[Federal Register Volume 78, Number 66 (Friday, April 5, 2013)]
[Proposed Rules]
[Pages 20718-20753]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-07781]
[[Page 20717]]
Vol. 78
Friday,
No. 66
April 5, 2013
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Parts 223 and 224
Endangered and Threatened Wildlife and Plants; Proposed Endangered,
Threatened, and Not Warranted Listing Determinations for Six Distinct
Population Segments of Scalloped Hammerhead Sharks; Proposed Rule
Federal Register / Vol. 78 , No. 66 / Friday, April 5, 2013 /
Proposed Rules
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Parts 223 and 224
[Docket No. 111025652-3245-02]
RIN 0648-XA798
Endangered and Threatened Wildlife and Plants; Proposed
Endangered, Threatened, and Not Warranted Listing Determinations for
Six Distinct Population Segments of Scalloped Hammerhead Sharks
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
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SUMMARY: In response to a petition submitted by WildEarth Guardians and
Friends of Animals to list the species as threatened or endangered, we,
NMFS, have completed a comprehensive status review under the Endangered
Species Act (ESA) for the scalloped hammerhead shark (Sphyrna lewini).
Based on the best scientific and commercial information available,
including the status review report (Miller et al., 2013), and other
information available since completion of the status review report, we
have determined that the species is comprised of six distinct
population segments (DPSs) that qualify as species under the ESA:
Northwest Atlantic and Gulf of Mexico (NW Atlantic & GOM DPS); Central
and Southwest Atlantic (Central & SW Atlantic DPS); Eastern Atlantic
DPS; Indo-West Pacific DPS; Central Pacific DPS; and Eastern Pacific
DPS. After reviewing the best available scientific and commercial
information on the DPSs, we have determined that two DPSs warrant
listing as endangered, the Eastern Atlantic and Eastern Pacific DPSs;
two DPSs warrant listing as threatened, the Central & SW Atlantic and
Indo-West Pacific DPSs; and two DPSs do not warrant listing at this
time, the NW Atlantic & GOM DPS and the Central Pacific DPS. Any
protective regulations determined to be necessary and advisable for the
conservation of the threatened DPSs under ESA section 4(d) would be
proposed in a subsequent Federal Register announcement. Should the
proposed listings be finalized, we would also designate critical
habitat for the species, to the maximum extent prudent and
determinable. We solicit information to assist these listing
determinations, the development of proposed protective regulations, and
designation of critical habitat in the event these proposed DPSs are
finally listed.
DATES: Comments on this proposed rule must be received by June 4, 2013.
Public hearing requests must be requested by May 20, 2013.
ADDRESSES: You may submit comments on this document, identified by the
code NOAA-NMFS-2011-0261 by any of the following methods:
Electronic Submissions: Submit all electronic comments via
the Federal eRulemaking Portal. Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2011-0261, click the ``Comment Now!'' icon,
complete the required fields, and enter or attach your comments.
Mail: Submit written comments to Office of Protected
Resources, NMFS, 1315 East-West Highway, Silver Spring, MD 20910.
Fax: 301-713-4060, Attn: Maggie Miller
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
www.regulations.gov without change. All personal identifying
information (e.g., name, address, etc.), confidential business
information, or otherwise sensitive information submitted voluntarily
by the sender will be publicly accessible. NMFS will accept anonymous
comments (enter ``N/A'' in the required fields if you wish to remain
anonymous). Attachments to electronic comments will be accepted in
Microsoft Word, Excel, or Adobe PDF file formats only. The proposed
rule and the status review report are also available electronically on
the NMFS Web site at http://www.nmfs.noaa.gov/pr/species/fish/scallopedhammerheadshark.htm.
FOR FURTHER INFORMATION CONTACT: Maggie Miller, NMFS, Office of
Protected Resources, (301) 427-8403.
SUPPLEMENTARY INFORMATION:
Background
On August 14, 2011, we received a petition from WildEarth Guardians
and Friends of Animals to list the scalloped hammerhead shark (Sphyrna
lewini) as threatened or endangered under the ESA throughout its entire
range, or, as an alternative, to delineate the species into five DPSs
(Eastern Central and Southeast Pacific, Eastern Central Atlantic,
Northwest and Western Central Atlantic, Southwest Atlantic, and Western
Indian Ocean) and list any or all of these DPSs as threatened or
endangered. The petitioners also requested that critical habitat be
designated for the scalloped hammerhead under the ESA. On November 28,
2011, we published a positive 90-day finding (76 FR 72891), announcing
that the petition presented substantial scientific or commercial
information indicating the petitioned action of listing the species may
be warranted and explained the basis for that finding. We also
announced the initiation of a status review of the species, as required
by Section 4(b)(3)(a) of the ESA, and requested information to inform
the agency's decision on whether the species warranted listing as
endangered or threatened under the ESA.
Listing Species Under the Endangered Species Act
We are responsible for determining whether scalloped hammerhead
sharks are threatened or endangered under the ESA (16 U.S.C. 1531 et
seq.) To make this determination, we first consider whether a group of
organisms constitutes a ``species'' under Section 3 of the ESA, then
whether the status of the species qualifies it for listing as either
threatened or endangered. Section 3 of the ESA defines species to
include ``any subspecies of fish or wildlife or plants, and any
distinct population segment of any species of vertebrate fish or
wildlife which interbreeds when mature.'' On February 7, 1996, NMFS and
the U.S. Fish and Wildlife Service (USFWS; together, the Services)
adopted a policy describing what constitutes a DPS of a taxonomic
species (61 FR 4722). The joint DPS policy identified two elements that
must be considered when identifying a DPS: (1) The discreteness of the
population segment in relation to the remainder of the species (or
subspecies) to which it belongs; and (2) the significance of the
population segment to the remainder of the species (or subspecies) to
which it belongs. As stated in the joint DPS policy, Congress expressed
its expectation that the Services would exercise authority with regard
to DPSs sparingly and only when the biological evidence indicates such
action is warranted.
Section 3 of the ESA defines an endangered species as ``any species
which is in danger of extinction throughout all or a significant
portion of its range'' and a threatened species as one ``which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range.'' Thus,
[[Page 20719]]
in the context of the ESA, the Services interpret an ``endangered
species'' to be one that is presently at risk of extinction. A
``threatened species,'' on the other hand, is not currently at risk of
extinction, but is likely to become so in the foreseeable future. In
other words, a key statutory difference between a threatened and
endangered species is the timing of when a species may be in danger of
extinction, either now (endangered) or in the foreseeable future
(threatened). The statute also requires us to determine whether any
species is endangered or threatened as a result of any one or a
combination of the following five factors: (A) The present or
threatened destruction, modification, or curtailment of its habitat or
range; (B) overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence (ESA, section 4(a)(1)(A)-(E)).
Section 4(b)(1)(A) of the ESA requires us to make listing
determinations based solely on the best scientific and commercial data
available after conducting a review of the status of the species and
after taking into account efforts being made by any State or foreign
nation or political subdivision thereof to protect the species. In
evaluating the efficacy of existing protective efforts, we rely on the
Services' joint Policy on Evaluation of Conservation Efforts When
Making Listing Decisions (``PECE''; 68 FR 15100; March 28, 2003). The
PECE provides direction for consideration of conservation efforts that
have not been implemented, or have been implemented but not yet
demonstrated effectiveness.
Status Review
We convened a team of agency scientists to conduct the status
review for the species and prepare a report. The status review report
of the scalloped hammerhead shark (Miller et al., 2013) compiles the
best available information on the status of the scalloped hammerhead
shark as required by the ESA, provides information on discreteness and
significance of populations and potential DPSs, and assesses the
current and future extinction risk for these scalloped hammerhead shark
populations, focusing primarily on threats related to the five
statutory factors set forth above. We appointed a contractor in the
Office of Protected Resources Endangered Species Division to undertake
a scientific review of the biology, population status and future
outlook for the scalloped hammerhead shark. Next we convened a team of
biologists and shark experts (Extinction Risk Analysis (ERA) team) to
conduct an extinction risk analysis for the scalloped hammerhead shark
populations, using the information in the scientific review. The ERA
team was comprised of a fishery biologist from NMFS Office of Protected
Resources, two fishery management specialists from NMFS' Highly
Migratory Species Management Division, two research fishery biologists
from NMFS' Southeast Fisheries Science Center and Pacific Island
Fisheries Science Center, and a fishery biologist contractor with NMFS'
Office of Protected Resources, with group expertise in shark biology
and ecology, population dynamics, highly migratory species management,
and stock assessment science. The status review report presents the ERA
team's professional judgment of the extinction risk facing each
population but makes no recommendation as to the listing status of
each. The status review report is available electronically at http://www.nmfs.noaa.gov/pr/species/fish/scallopedhammerheadshark.htm.
The status review report was peer reviewed by three scientists with
scalloped hammerhead shark expertise from academic institutions. The
peer reviewers were asked to evaluate the adequacy, appropriateness,
and application of data used in the Status Review document as well to
evaluate the findings made in the ``Assessment of Extinction Risk''
section of the report. We subsequently reviewed the status review
report, its cited references, and peer review comments, and believe the
status review report, upon which this proposed rule is based, provides
the best available scientific and commercial information on the
scalloped hammerhead shark. Much of the information discussed below on
scalloped hammerhead shark biology, distribution, abundance, threats,
and extinction risk is attributable to the status review report.
However, we have independently applied the statutory provisions of the
ESA, including evaluation of the factors set forth in Section
4(a)(1)(A)-(E); our regulations regarding listing determinations; and
our DPS policy in making the proposed listing determinations.
Life History, Biology, and Status of the Petitioned Species
Taxonomy and Species Description
All hammerhead sharks belong to the family Sphyrnidae and are
classified as ground sharks (Order Carcharhiniformes). Most hammerheads
belong to the Genus Sphyrna with one exception, the winghead shark (E.
blochii), which is the sole species in the Genus Eusphyra. The
hammerhead sharks are recognized by their laterally expanded head that
resembles a hammer, hence the common name ``hammerhead.'' The scalloped
hammerhead shark (Sphyrna lewini) is distinguished from other
hammerheads by a marked central indentation on the anterior margin of
the head, along with two more indentations on each side of this central
indentation, giving the head a ``scalloped'' appearance. It has a
broadly arched mouth and the rear margin of the head is slightly swept
backward. The dentition of the hammerhead consists of small, narrow,
and triangular teeth with smooth edges (often slightly serrated in
larger individuals), and is similar in both jaws. The front teeth are
erect while subsequent teeth have oblique cusps, and the lower teeth
are more erect than the upper teeth (Bester, n.d.).
The body of the scalloped hammerhead is fusiform, with a large
first dorsal fin and low second dorsal and pelvic fins. The first
dorsal fin is moderately hooked with its origin over or slightly behind
the pectoral fin insertions and the rear tip in front of the pelvic fin
origins. The height of the second dorsal fin is less than the anal fin
height and has a posterior margin that is approximately twice the
height of the fin, with the free rear tip almost reaching the precaudal
pit. The pelvic fins have relatively straight rear margins while the
anal fin is deeply notched on the posterior margin (Compagno, 1984).
The scalloped hammerhead shark generally has a uniform gray, grayish
brown, bronze, or olive coloration on top of the body that shades to
white on the underside with dusky or black pectoral fin tips.
Current Distribution
The scalloped hammerhead shark can be found in coastal warm
temperate and tropical seas worldwide. In the western Atlantic Ocean,
the scalloped hammerhead range extends from the northeast coast of the
United States (from New Jersey to Florida) to Brazil, including the
Gulf of Mexico and Caribbean Sea. In the eastern Atlantic, it can be
found from the Mediterranean to Namibia. Populations in the Indian
Ocean are found in the following locations: South Africa and the Red
Sea to Pakistan, India, and Myanmar, and in the western Pacific the
scalloped hammerhead can be found from Japan and China to New
Caledonia, including throughout the Philippines, Indonesia, and off
Australia. Distribution in the
[[Page 20720]]
eastern Pacific Ocean extends from the coast of southern California
(U.S.), including the Gulf of California, to Ecuador and possibly Peru
(Compagno, 1984), and off waters of Hawaii (U.S.) and Tahiti. The
scalloped hammerhead shark occurs over continental and insular shelves,
as well as adjacent deep waters, but is seldom found in waters cooler
than 22[deg] C (Compagno, 1984; Schulze-Haugen and Kohler, 2003). It
ranges from the intertidal and surface to depths of up to 450-512 m
(Sanches, 1991; Klimley, 1993), with occasional dives to even deeper
waters (Jorgensen et al., 2009). It has also been documented entering
enclosed bays and estuaries (Compagno, 1984).
Movement and Habitat Use
Scalloped hammerhead sharks are highly mobile and partly migratory
and are likely the most abundant of the hammerhead species (Maguire et
al., 2006). These sharks have been observed making primarily short-
distance migrations along continental margins as well as between
oceanic islands in tropical waters, with tagging studies revealing the
tendency for scalloped hammerhead sharks to aggregate around and travel
to and from core areas or ``hot spots'' within locations (Holland et
al., 1993; Kohler and Turner, 2001; Duncan and Holland, 2006; Hearn et
al., 2010; Bessudo et al., 2011; Diemer et al., 2011). However,
scalloped hammerhead sharks are also capable of traveling long
distances (1,941 km, Bessudo et al., 2011; 1,671 km, Kohler and Turner,
2001; Hearn et al., 2010), and in many of these tagging studies the
sharks were tracked leaving the study area for long periods of time,
ranging from 2 weeks to several months (Hearn et al., 2010; Bessudo et
al., 2011) to almost a year (324 days) (Duncan and Holland, 2006)
before eventually returning, displaying a level of site fidelity to
these areas.
Both juveniles and adult scalloped hammerhead sharks occur as
solitary individuals, pairs, or in schools. The schooling behavior has
been documented during summer migrations off the coast of South Africa
as well as in permanent resident populations, like those in the East
China Sea (Compagno, 1984). Adult aggregations are most common offshore
over seamounts and near islands, especially near the Galapagos,
Malpelo, Cocos and Revillagigedo Islands, and within the Gulf of
California (Compagno, 1984; CITES, 2010; Hearn et al., 2010; Bessudo et
al., 2011). Neonate and juvenile aggregations are more common in
nearshore nursery habitats, such as K[amacr]ne'ohe Bay in Oahu, Hawaii,
coastal waters off Oaxaca, Mexico, and Guam's inner Apra Harbor (Duncan
and Holland, 2006; Bejarano-[Aacute]lvarez et al., 2011). It has been
suggested that juveniles inhabit these nursery areas for up to or more
than a year, as they provide valuable refuges from predation (Duncan
and Holland, 2006).
Diet
The scalloped hammerhead shark is a high trophic level predator
(trophic level = 4.1; Cort[eacute]s, 1999) and opportunistic feeder
with a diet that includes a wide variety of teleosts, cephalopods,
crustaceans, and rays (Compagno, 1984; Bush, 2003; J[uacute]nior et
al., 2009; Noriega et al., 2011). In a study on feeding behavior in
K[amacr]ne'ohe Bay, Bush (2003) found a nocturnal increase in the rate
of foraging by juvenile scalloped hammerheads, with sharks consuming a
mixture of crustaceans and teleosts. The alpheid and goby species were
the most important prey items in their diet. Off the coast of Brazil,
immature S. lewini frequently fed on reef and pelagic fish, as well as
cephalopod species (Chiroteuthis sp. and Vampyroteuthis infernalis)
that inhabit deep waters (J[uacute]nior et al., 2009). Stomachs of 466
S. lewini off the coast of Australia revealed the importance of bony
fish as a prey item, followed by elasmobranchs, octopus and squid, and
baitfish, with a positive correlation between shark length and the
proportion of elasmobranchs in stomach contents (Noriega et al., 2011).
Reproduction
The scalloped hammerhead shark is viviparous (i.e., give birth to
live young), with a gestation period of 9-12 months (Branstetter, 1987;
Stevens and Lyle, 1989), which may be followed by a one-year resting
period (Liu and Chen, 1999). Females attain maturity around 200-250 cm
total length (TL) while males reach maturity at smaller sizes (range
128-200 cm TL). Estimates of age at maturity vary by region, ranging
from 3.8 to 15.2 years, but are likely a result of differences in band
interpretations in aging methodology approaches (Piercy et al., 2007).
Parturition, however, does not appear to vary by region and may be
partially seasonal (Harry et al., 2011), with neonates present year
round but with abundance peaking during the spring and summer months
(Duncan and Holland, 2006; Adams and Paperno, 2007; Bejarano-
[Aacute]lvarez et al., 2011; Harry et al. 2011; Noriega et al., 2011).
Females move inshore to birth, with litter sizes anywhere between 1 and
41 live pups. Off the coast of northeastern Australia, Noriega et al.
(2011) found a positive correlation between litter size and female
shark length for scalloped hammerheads, as did White et al. (2008) in
Indonesian waters. However, off the northeastern coast of Brazil, Hazin
et al. (2001) found no such relationship.
Growth
Total length at birth estimates range from 313 mm TL (Chen et al.,
1990) to 570 mm TL (White et al., 2008). Duncan and Holland (2006)
calculated an early juvenile growth rate of 9.6 cm per year. Observed
maximum sizes for male scalloped hammerheads range from 196-321 cm TL,
with the oldest male scalloped hammerhead estimated at 30.5 years
(Piercy et al., 2007). Observed maximum sizes for female scalloped
hammerheads range from 217-346 cm TL, with the oldest female scalloped
hammerhead estimated at 31.5 years (Kotas et al., 2011). Estimates of
the von Bertalanffy growth parameters vary by study, location, and sex
of the animal, with the following ranges: L[infin] = 212 to 519 cm TL,
k = 0.05 to 0.25 year-1, t0 = -3.9 to -0.4 (see Miller et
al., 2013).
The life history of the scalloped hammerhead shark, like most
elasmobranchs, is characterized as long lived (at least 20-30 years),
late maturing, and relatively slow growing (based on Branstetter
(1990), where k < 0.1/year indicates slow growth for sharks), which
generally contributes to a low intrinsic rate of increase. Using life
history parameters from the Atlantic S. lewini populations, estimates
of the intrinsic rate of increase (r) for the scalloped hammerhead
shark range from 0.028 (Smith et al., 1998) to 0.157 (Cort[eacute]s et
al., 2010). Based on the Food and Agriculture Organization of the
United Nations (FAO) productivity indices for exploited fish species
(where r < 0.14 is considered low productivity), overall estimates of
(r) values for the scalloped hammerhead shark indicate that S. lewini
populations are generally vulnerable to depletion and may be slow to
recover from overexploitation.
Current Status
Scalloped hammerhead sharks can be found worldwide, with no present
indication of a range contraction. The oldest living S. lewini
populations are found in the central Indo-West Pacific, indicating this
region as the origin of the species (Duncan et al., 2006; Daly-Engel et
al., 2012). During the late Pleistocene period, S. lewini underwent
several dispersal events (Duncan et al., 2006). Following the closing
of the Isthmus of Panama, it was suggested that gene flow occurred from
west to east, with S. lewini traveling from the Atlantic Ocean into the
Indo-Pacific, via southern Africa (Duncan et al., 2006).
[[Page 20721]]
Scalloped hammerhead sharks are both targeted and taken as bycatch
in many global fisheries, with their fins a primary product for
international trade. To a much lesser extent, scalloped hammerhead
sharks are also caught for their meat (with Colombia, Kenya, Mexico,
Mozambique, Philippines, Seychelles, Spain, Sri Lanka, China (Taiwan),
Tanzania, and Uruguay identified as countries that consume hammerhead
meat (Vannuccini, 1999; CITES, 2010)). However, given the fact that the
meat is essentially unpalatable, due to its high urea concentration, it
is thought that current volume of S. lewini traded meat and products is
insignificant when compared to the volume of S. lewini fins in
international trade (CITES, 2010). Unfortunately, the lack of species-
specific reporting in these trade products, as well as the scarcity of
information on the fisheries catching scalloped hammerhead sharks prior
to the early 1970s, with only occasional mentions in historical
records, makes it difficult to assess the current worldwide scalloped
hammerhead shark status.
In 2007, the International Union for Conservation of Nature (IUCN)
considered the scalloped hammerhead shark to be endangered globally,
based on an assessment by Baum et al. (2007) and its own criteria (A2bd
and 4bd), and placed the species on its ``Red List.'' Under criteria
A2bd and 4bd, a species may be classified as endangered when its
``observed, estimated, inferred or suspected'' population size is
reduced by 50% or more over the last 10 years, any 10 year time period,
or three generation period, whichever is the longer, and where the
causes of reduction may not have ceased, be understood, or be
reversible based on an index of abundance appropriate to the taxon and/
or the actual or potential levels of exploitation. IUCN justification
for the categorization includes both species-specific estimates and
estimates for the entire hammerhead family that suggest declines in
abundance of 50-90 percent over time periods of up to 32 years in
various regions of the species' range. The IUCN inferred similar
declines in areas where species-specific data are unavailable, but
where there is evidence of substantial fishing pressure on the
scalloped hammerhead shark. As a note, the IUCN classification for the
scalloped hammerhead shark alone does not provide the rationale for a
listing recommendation under the ESA, but the sources of information
that the classification is based upon are evaluated in light of the
standards on extinction risk and impacts or threats to the species.
Identification of Distinct Population Segments
As described above, the ESA's definition of ``species'' includes
``any subspecies of fish or wildlife or plants, and any distinct
population segment of any species of vertebrate fish or wildlife which
interbreeds when mature.'' The genetic diversity among subpopulations,
geographic isolation, and differences in international regulatory
mechanisms provide evidence that several populations of scalloped
hammerhead sharks meet the DPS Policy criteria. Therefore, prior to
evaluating the conservation status for scalloped hammerhead sharks, and
in accordance with the joint DPS policy, we considered: (1) The
discreteness of any scalloped hammerhead shark population segment in
relation to the remainder of the subspecies to which it belongs; and
(2) the significance of any scalloped hammerhead shark population
segment to the remainder of the subspecies to which it belongs.
Discreteness
The Services' joint DPS policy states that a population of a
vertebrate species may be considered discrete if it satisfies either
one of the following conditions: (1) It is markedly separated from
other populations of the same taxon as a consequence of physical,
physiological, ecological, or behavioral factors (quantitative measures
of genetic or morphological discontinuity may provide evidence of this
separation) or (2) it is delimited by international governmental
boundaries within which differences in control of exploitation,
management of habitat, conservation status, or regulatory mechanisms
exist that are significant in light of Section 4(a)(1)(D) of the ESA.
To inform its decisions with respect to possible scalloped hammerhead
DPSs, the ERA team mainly relied on genetic data, tagging studies, and
evidence of differences in the control of exploitation and management
by international governmental bodies.
Although scalloped hammerhead sharks are highly mobile, this
species rarely conducts trans-oceanic migrations (Kohler and Turner,
2001; Duncan and Holland, 2006; Duncan et al., 2006; Chapman et al.,
2009; Diemer et al., 2011). Female scalloped hammerhead sharks may even
display a level of site fidelity for reproduction purposes (Duncan et
al., 2006; Chapman et al., 2009) that likely contributes to the
apparent genetic discontinuity in the global scalloped hammerhead shark
population (Duncan et al., 2006; Chapman et al., 2009; Daly-Engel et
al., 2012). Genetics analyses for scalloped hammerhead sharks using
mitochondrial DNA (mtDNA), which is maternally inherited, and
microsatellite loci data, which reflects the genetics of both parents,
have consistently shown that scalloped hammerhead subpopulations are
genetically diverse and that individual subpopulations can be
differentiated, especially those populations separated by ocean basins
(Duncan et al., 2006; Chapman et al., 2009; Ovenden et al., 2011; Daly-
Engel et al., 2012). Using mtDNA samples, Duncan et al. (2006)
discovered no sharing of haplotypes between S. lewini in the Atlantic
and those from the Pacific or Indian Ocean, proving genetic isolation
by oceanic barriers. Chapman et al. (2009) further substantiated this
finding in a subsequent examination of mtDNA from scalloped hammerhead
shark fins, confirming the absence of shared haplotypes between S.
lewini in the western Atlantic (n = 177) and those found in the Indo-
Pacific (n = 275). Using microsatellite loci from 403 S. lewini
samples, Daly-Engel et al. (2012) concluded that scalloped hammerhead
sharks in the western and eastern Atlantic Ocean were significantly
differentiated from other populations in the Pacific and Indian Oceans,
suggesting that the male sharks in the Atlantic Ocean rarely mix with
scalloped hammerheads found elsewhere in the world.
Atlantic Ocean Population Segments
Further delineation within ocean basins is supported by regional
and global genetic studies as well as tagging data. For example, in the
Atlantic, both mitochondrial and microsatellite data indicate genetic
discontinuity within this ocean basin, with distinct populations of
scalloped hammerhead sharks defined by their respective coasts.
Analysis of S. lewini haplotypes from samples taken off West Africa and
the East Coast of the United States reveal genetic separation of these
two populations and point to missing hypothetical ancestors (Duncan et
al., 2006). Using biparentally-inherited DNA, Daly-Engel et al. (2012)
also provided evidence of genetic structure across the Atlantic Ocean,
with scalloped hammerhead samples from West Africa weakly
differentiated from South Carolina samples (FST = 0.052,
0.05 >= P >= 0.01) and significantly differentiated from Gulf of Mexico
samples (FST = 0.312, P <= 0.001). These studies confirm the
genetic isolation of the eastern and western Atlantic scalloped
hammerhead populations,
[[Page 20722]]
which should be treated as separate and discrete populations (Chapman
personal communication, 2012).
Finer scale delineation within the western Atlantic population is
also warranted based on analysis of both maternally and bi-parentally
inherited DNA; however, the boundaries of this delineation are
unresolved. For example, Chapman et al. (2009) structured the western
Atlantic scalloped hammerhead population into three distinct
mitochondrial stocks: the northern (U.S. Atlantic and Gulf of Mexico),
central (Central American Caribbean), and southern (Brazil) stocks.
Daly-Engel et al. (2012), on the other hand, found significant
population differentiation in between the Gulf of Mexico and the nearby
South Carolina site in the western Atlantic (FST = 0.201, P
< 0.001) using microsatellite fragments. This finding contrasts with
Chapman et al. (2009) who did not find significant population
differentiation between S. lewini in the U.S. Atlantic and the Gulf of
Mexico, and Duncan et al. (2006) who found a lack of genetic structure
along continental margins using mtDNA samples. Thus, although the
genetic data support dividing the western Atlantic population into
subpopulations, there is disagreement on where the lines should be
drawn.
Since differences in genetic composition can sometimes be explained
by the behavior of a species, the ERA team examined tagging data to
learn more about the movements of the scalloped hammerhead populations
along the western Atlantic coast. The available data corroborate the
genetic findings that these populations of scalloped hammerhead sharks
rarely travel long distances. In fact, the median distance between mark
and recapture of 3,278 adult scalloped hammerhead sharks, tagged along
the eastern U.S. coast and Gulf of Mexico, was less than 100 km (Kohler
and Turner, 2001). In addition, none of these tagged sharks were
tracked moving south (Kohler personal communication, 2012), indicating
a potential separation of the northwest Atlantic and Gulf of Mexico
population from the Central and South American population based on
movement behavior (Kohler personal communication, 2012).
To further inform its decisions as to whether there is discreteness
amongst the western Atlantic scalloped hammerhead subpopulations, the
ERA team looked at possible differences in current conservation status
and regulatory mechanisms across international boundaries. In the
northwest Atlantic and Gulf of Mexico, the United States has
implemented strict regulations aimed at controlling the exploitation of
the sharks, including the scalloped hammerhead, with the development of
fishery management plans (FMPs), requirement for stock assessments, and
quota monitoring. On August 29, 2011, NMFS prohibited the taking of
scalloped hammerhead sharks by the U.S. commercial highly migratory
species (HMS) pelagic longline fishery and recreational fisheries for
tunas, swordfish, and billfish in the Atlantic Ocean, including the
Caribbean Sea and Gulf of Mexico (76 FR 53652; August 29, 2011). These
comprehensive regulatory mechanisms are expected to help protect S.
lewini in the northwest Atlantic and Gulf of Mexico. Although the U.S.
regulations extend to the U.S. economic exclusive zone (EEZ) in the
Caribbean (i.e., surrounding U.S. territories), the vast majority of
the Caribbean sea, as well as waters farther south, lack regulatory
measures controlling the exploitation of scalloped hammerheads. For
example, Brazil, a country that has seen declines of 80 percent or more
in catch per unit effort (CPUE) of scalloped hammerheads in various
fisheries (FAO, 2010), does not have regulations specific to scalloped
hammerhead sharks or quota monitoring of the species. Many countries in
Central America are also either lacking protections for shark species
or have major problems with enforcement of their respective fishery
regulations (Kyne et al., 2012). Thus, the species continues to be
heavily fished for by industrial and artisanal fishers in waters off
Central and South America. Due to these differences in control of
exploitation and regulatory mechanisms for management and conservation
of this species across international boundaries, and coupled with the
results from the genetic analyses and tagging studies, the ERA team
concluded that the western Atlantic population is, in fact, two
discrete subpopulations: the Northwest Atlantic & Gulf of Mexico
population and the Central & Southwest Atlantic population. We find
both of these population segments satisfy the discreteness criterion
under the DPS policy.
Indo-West Pacific Population Segments
Within the Indo-West Pacific region, a lack of genetic structure
suggests frequent mixing of scalloped hammerhead populations found in
these waters (Daly-Engel et al., 2012). A comparison of microsatellite
loci samples from the Indian Ocean, specifically samples from the
Seychelles and West Australia, as well as from South Africa and West
Australia, indicated either no or weak population differentiation
(Daly-Engel et al., 2012). Additionally, there was no evidence of
genetic structure between the Pacific and Indian Oceans, as samples
from Taiwan, Philippines, and East Australia in the western Pacific
showed no population differentiation from samples in the Indian Ocean
(FST = -0.018, P = 0.470) (Daly-Engel et al., 2012).
Although these genetic data may imply that males of the species move
widely within this region, potentially across ocean basins, tagging
studies suggest otherwise. Along the east coast of South Africa, for
example, S. lewini moved an average distance of only 147.8 km (data
from 641 tagged scalloped hammerheads; Diemer et al., 2011). Tagging
studies in other regions also suggest limited distance movements, and
only along continental margins, coastlines, or between islands with
similar oceanographic conditions (Kohler and Turner, 2001; Duncan and
Holland, 2006; Bessudo et al., 2011). Thus, it seems more likely that
the high connectivity of the habitats found along the Indian and
western Pacific coasts has provided a means for this shark population
to mix and reproduce without having to traverse deep ocean basins. In
fact, along the east coast of Australia, Ovenden et al. (2011) found
evidence of only one genetic stock of S. lewini. The samples, spanning
almost 2,000 km of coastline on Australia's east coast, showed genetic
homogeneity based on eight microsatellite loci and mtDNA markers,
suggesting long-shore dispersal and panmixia of scalloped hammerhead
sharks (Ovenden et al., 2011). No genetic subdivision existed between
Indonesia and the eastern or northern coasts of Australia, suggesting
this species may move widely between the connecting habitats of
Australia and Indonesia (Ovenden et al., 2009; Ovenden et al., 2011).
Although the aforementioned genetic analyses suggest males of the
Indo-West Pacific population appear to make longer distance coastal
movements than what the Atlantic subpopulations typically exhibit
(Daly-Engel et al., 2012), they have not been observed mixing with the
neighboring eastern Atlantic population of sharks. The significant
levels of genetic structure between S. lewini microsatellite samples
from South Africa and those from West Africa samples (FST =
0.07, P <= 0.01) corroborate this finding, with the number of migrants
moving between these two locations estimated at 0.06 to 0.99 per
generation (Daly-Engel et al., 2012). Thus, although connected by a
continuous coastline, the genetic data
[[Page 20723]]
indicate that the eastern Atlantic population and Indo-West Pacific
populations rarely mix and qualify as discrete populations due to these
genetic differences.
Pacific Ocean Population Segments
In addition to the Indo-West Pacific population, the ERA team found
evidence of two other possible subpopulations of scalloped hammerheads
in the Pacific Ocean: those common in the Central Pacific region and
those found in the East Pacific region. The Central Pacific
subpopulation of scalloped hammerheads appears to be markedly separate
from other S. lewini populations within the Pacific Ocean as a
consequence of physical and genetic factors. The Central Pacific
population is located in the middle of the Pacific Ocean. Their range
primarily encompasses the Hawaiian Archipelago, which includes the
inhabited main islands in the southeast as well as the largely
uninhabited Papah[amacr]naumoku[amacr]kea Marine National Monument that
extends from Nihoa to Kure Atoll in the northwest. Johnston Atoll is
also included in this population's range due to its proximity to the
Hawaiian Archipelago. In order to reach the other neighboring
populations in the western and eastern Pacific, the Central Pacific
scalloped hammerhead sharks would have to travel over hundreds to
thousands of kilometers, overcoming various bathymetric barriers.
However, as previously mentioned, tagging studies and mtDNA analyses
suggest this species rarely makes long-distance oceanic migrations.
Instead, the data support the assumption that this species more
commonly disperses along continuous coastlines, continental margins,
and submarine features, such as chains of seamounts, commonly
associated with scalloped hammerhead shark ``hotspots'' (Holland et
al., 1993; Kohler and Turner, 2001; Duncan and Holland, 2006; Hearn et
al., 2010; Bessudo et al., 2011; Diemer et al., 2011). This is true
even for island populations, with tagged S. lewini individuals
frequently migrating to nearby islands and mainlands (Duncan and
Holland, 2006; Hearn et al., 2010; Bessudo et al., 2011), but no
evidence or data to support oceanic migration behavior.
For example, Bessudo et al. (2011) observed scalloped hammerhead
sharks in the Eastern Tropical Pacific (ETP) and noted that although
they are capable of covering long distances (i.e., 1941 km), the sharks
remain within the area, moving widely around and occasionally between
neighboring islands with similar oceanographic conditions. A study
conducted in a nursery ground in Hawaii revealed that sharks travelled
as far as 5.1 km in the same day, but the mean distance between capture
points was only 1.6 km (Duncan and Holland, 2006). Another tagging
study in Hawaii indicates that adult males remain ``coastal'' within
the archipelago (Holland personal communication, 2012). The genetic
data from scalloped hammerhead populations also supports this theory of
limited oceanic dispersal, with significant genetic discontinuity
associated with oceanic barriers but less so along continental margins
(Duncan et al., 2006; Chapman et al., 2009; Daly-Engel et al., 2012).
With regards to the S. lewini sharks in Central Pacific and Eastern
Pacific, both microsatellite loci and mtDNA data indicate significant
genetic differentiation between these two populations (Daly-Engel et
al., 2011), corroborating the theory of genetic isolation due to
biogeographic barriers. Thus, these genetic analyses, coupled with the
tagging studies, suggest that the populations of scalloped hammerhead
sharks found in the Pacific (i.e. Indo-West Pacific, Central Pacific,
and East Pacific subpopulations) rarely conduct open ocean migrations
(Kohler and Turner, 2001; Bessudo et al., 2011; Diemer et al., 2011;
Holland personal communication, 2012) to mix or reproduce with each
other.
Further separating these subpopulations, especially the Central
Pacific scalloped hammerhead population from its neighboring western
and eastern Pacific populations, are the differences in fisheries
regulations across these international boundaries. The Central Pacific
currently has many management controls in place that protect important
scalloped hammerhead habitats and nursery grounds, as well as fishing
regulations that control the exploitation of the species. For example,
the fisheries of the Hawaiian Islands are managed by both Federal
regulations, such as the Magnuson-Stevens Fishery Conservation and
Management Act (MSA), and state regulations aimed at protecting and
conserving marine resources. Currently, there are no directed shark
fisheries in Hawaii; however, scalloped hammerheads are sometimes
caught as bycatch on Hawaiian longline gear. The Hawaii pelagic
longline (PLL) fishery, which operates mainly in the Northern Central
Pacific Ocean, is managed through a Fishery Ecosystem Plan (FEP)
developed by the Western Pacific Regional Fishery Management Council
(WPFMC) and approved by NMFS under the authority of the MSA. In an
effort to reduce bycatch in this fishery, a number of gear regulations
and fishery management measures have been implemented. For example, a
50-75 nm (92.6-138.9 km) longline fishing buffer zone exists around the
Hawaiian Islands, helping to protect scalloped hammerheads from being
caught near popular nursery grounds and their coastal adult habitat.
Periodic closures and effort limits in the shallow-set sector of this
fishery (which has a higher shark catch rate) also helps protect
scalloped hammerheads in this fishery.
In addition, mandatory fishery observers have been monitoring both
sectors (shallow and deep) of the limited-entry Hawaii-based PLL
fishery since 1994, with observer coverage increasing in recent years
to provide a more comprehensive bycatch dataset. Shark finning, a
practice which involves harvesting sharks, severing their fins and
returning their remaining carcasses to the sea, was banned in 2000 for
the Hawaii-based longline fishery. Additionally, the U.S. Shark
Conservation Act of 2010 requires that sharks lawfully harvested in
Federal waters, including those located in the range of this DPS, be
landed with their fins naturally attached, and additional legislation
aimed at shark finning was enacted in 2010 by the State of Hawaii
(State of Hawaii SB2169). In the neighboring ETP, as well as other
islands and countries in the western Pacific, regulatory mechanisms are
either missing, inadequate, or weakly enforced, and illegal fishing is
widespread. Therefore, it is reasonable to assume that the differences
in the control of exploitation and regulatory mechanisms between the
Central Pacific and the surrounding countries could influence the
conservation status of the scalloped hammerhead population around the
Central Pacific region and thus could be considered a discrete
population under the DPS policy.
In the eastern Pacific region, results from both microsatellite
loci data and mtDNA confirm the genetic isolation of the eastern
Pacific S. lewini population from those found in the central and
western Pacific, Indian, and Atlantic Oceans (P <= 0.001) (Daly-Engel
et al., 2012). Nance et al. (2011) suggested that the ETP S. lewini
population may actually exist as a series of small and genetically
separate populations. This observed low genetic diversity in the
eastern Pacific population may indicate peripatric speciation (i.e.,
formation of new species in isolated peripheral populations that are
much smaller than
[[Page 20724]]
the original population) from the Indo-West Pacific hammerhead
population (Duncan et al., 2006). Interestingly, when compared to
samples from the Gulf of Mexico, Daly-Engel et al. (2012) found high
levels of allelic differentiation (FST = 0.519, P <= 0.001),
suggesting that these two populations have never mixed and thus make up
the opposing ends of the S. lewini dispersal range from the Indo-West
Pacific. The genetic differentiation and geographic isolation of the
Eastern Pacific population from other scalloped hammerhead populations
thus qualify it as a discrete population under the DPS policy.
Based on the above information on scalloped hammerhead population
structuring, as well as additional information provided in the status
review report, we have concluded that the following six discrete
subpopulations of scalloped hammerhead sharks are present in the world:
(1) Northwest Atlantic & Gulf of Mexico population segment, (2) Central
& Southwest Atlantic population segment, (3) Eastern Atlantic
population segment, (4) Indo-West Pacific population segment, (5)
Central Pacific population segment, and (6) Eastern Pacific population
segment. Each is markedly separate from the other five population
segments as a consequence of genetic and/or physical factors, with some
population segments also delimited by international governmental
boundaries within which differences in control of exploitation,
conservation status, or regulatory mechanisms exist that are
significant in light of Section 4(a)(1)(D) of the ESA.
Significance
When the discreteness criterion is met for a potential DPS, as it
is for the Northwest Atlantic & Gulf of Mexico, Central & Southwest
Atlantic, Eastern Atlantic, Indo-West Pacific, Central Pacific, and
Eastern Pacific population segments identified above, the second
element that must be considered under the DPS policy is significance of
each DPS to the taxon as a whole. Significance is evaluated in terms of
the importance of the population segment to the overall welfare of the
species. Some of the considerations that can be used to determine a
discrete population segment's significance to the taxon as a whole
include: (1) Persistence of the population segment in an unusual or
unique ecological setting; (2) evidence that loss of the population
segment would result in a significant gap in the range of the taxon;
and (3) evidence that the population segment differs markedly from
other populations of the species in its genetic characteristics.
Based on the results from the genetic and tagging analyses
mentioned previously, we believe that there is evidence that loss of
any of the population segments would result in a significant gap in the
range of the taxon. For example, the Indo-West Pacific region, which is
hypothesized as the center of origin for S. lewini, with the oldest
extant scalloped hammerhead species found in this region (Duncan et
al., 2006; Daly-Engel et al., 2012), covers a wide swath of the
scalloped hammerhead sharks' range (extending from South Africa to
Japan, and south to Australia and New Caledonia and neighboring Island
countries). However, as Daly-Engel et al. (2012) notes, the migration
rate of S. lewini individuals from West Africa into South Africa is
very low (0.06 individuals per generation), suggesting that in the case
of an Indo-West Pacific extirpation, re-colonization from the Eastern
Atlantic to the Western Indian Ocean is very unlikely. In addition, re-
colonization from the Central Pacific DPS would also occur rather
slowly (on an evolutionary timescale) as those individuals would have
to conduct trans-oceanic migrations, a behavior that has yet to be
documented in this species. The Central Pacific region, itself
(extending from Kure Atoll to Johnston Atoll, and including the
Hawaiian Archipelago), encompasses a vast portion of the scalloped
hammerhead sharks' range in the Pacific Ocean and is isolated from the
neighboring Indo-West Pacific and eastern Pacific regions by deep
expanses of water. Loss of this DPS would result in a decline in the
number of suitable and productive nursery habitats and create a
significant gap in the range of this taxon across the Pacific Ocean.
From an evolutionary standpoint, the Central Pacific population is
thought to be the ``stepping stone'' for colonization to the isolated
ETP, as Duncan et al. (2006) observed two shared haplotypes between
Hawaii and the otherwise isolated ETP population. In other words, in
the case of an ETP extirpation and loss of the Central Pacific
population, it would require two separate and rare colonization events
to repopulate the ETP population: one for the re-colonization of the
Central Pacific and another for the re-colonization of the ETP. Thus,
on an evolutionary timescale, loss of the Central Pacific population
would result in a significant truncation in the range of the taxon.
Even those discrete population segments that share a connecting
coastline, like the Northwest Atlantic & Gulf of Mexico and Central &
Southwest Atlantic population segments, will not likely see individuals
re-colonizing the other population segment, given that gene flow is low
between these areas and tagging studies show limited distance movements
by individuals along the western Atlantic coast. In addition,
repopulation by individuals from the eastern Pacific to the western
Atlantic, or vice versa, is highly unlikely as these animals would have
to migrate through suboptimal oceanographic conditions, such as very
cold waters, that are detrimental to this species' survival. Therefore,
the display of weak philopatry and constrained migratory movements
provides evidence that loss of any of the discrete population segments
would result in a significant gap in the range of the scalloped
hammerhead shark, negatively impacting the species as a whole.
In summary, the scalloped hammerhead shark population segments
considered by the ERA team meet both the discreteness and significance
criterion of the DPS policy. We concur with the ERA team's conclusion
that there are six scalloped hammerhead shark DPSs, which comprise the
global population, and are hereafter referred to as: (1) NW Atlantic &
GOM DPS, (2) Central & SW Atlantic DPS, (3) Eastern Atlantic DPS, (4)
Indo-West Pacific DPS, (5) Central Pacific DPS, and (6) Eastern Pacific
DPS. The boundaries for each of these DPSs, as determined from the DPS
analysis, are as follows (see Figure 1):
(1) NW Atlantic & GOM DPS--Bounded to the north by 40[deg] N.
latitude (lat.), includes all U.S. EEZ waters in the Northwest Atlantic
and extends due east along 28[deg] N. lat. off the coast of Florida to
30[deg] W. longitude (long.). In the Gulf of Mexico, the boundary line
includes all waters of the Gulf of Mexico, with the eastern portion
bounded by the U.S. and Mexico EEZ borders.
(2) Central & SW Atlantic DPS--Bounded to the north by 28[deg] N.
lat., to the east by 30[deg] W. long., and to the south by 36[deg] S.
lat. All waters of the Caribbean Sea are within this DPS boundary,
including the Bahamas' EEZ off the coast of Florida as well as Cuba's
EEZ.
(3) Eastern Atlantic DPS--Bounded to the west by 30[deg] W. long.,
to the north by 40[deg] N. lat., to the south by 36[deg] S. lat., and
to the east by 20[deg] E. long., but includes all waters of the
Mediterranean Sea.
(4) Indo-West Pacific DPS--Bounded to the south by 36[deg] S. lat.,
to the west by 15[deg] E. long., and to the north by 40[deg] N. lat. In
the east, the boundary line extends from 175[deg] W. long. due south to
10[deg] N. lat., then due east along 10[deg] N.
[[Page 20725]]
lat. to 140[deg] W. long., then due south to 4[deg] S. lat., then due
east along 4[deg] S. lat. to 130[deg] W. long, and then extends due
south along 130[deg] W. long.
(5) Central Pacific DPS--Bounded to the north by 40[deg] N lat., to
the east by 140[deg] W. long., to the south by 10[deg] N. lat., and to
the west by 175[deg] E. long.
(6) Eastern Pacific DPS--bounded to the north by 40[deg] N lat. and
to the south by 36[deg] S lat. The western boundary line extends from
140[deg] W. long. due south to 10[deg] N., then due west along 10[deg]
N. lat. to 140[deg] W. long., then due south to 4[deg] S. lat., then
due east along 4[deg] S. lat. to 130[deg] W. long, and then extends due
south along 130[deg] W. long.
[GRAPHIC] [TIFF OMITTED] TP05AP13.001
Assessment of Extinction Risk
The Endangered Species Act (ESA) (Section 3) defines endangered
species as ``any species which is in danger of extinction throughout
all or a significant portion of its range.'' Threatened species are
``any species which is likely to become an endangered species within
the foreseeable future throughout all or a significant portion of its
range.'' Neither we nor the USFWS have developed any formal policy
guidance about how to interpret the definitions of threatened and
endangered. We consider a variety of information and apply professional
judgment in evaluating the level of risk faced by a species in deciding
whether the species is threatened or endangered. We evaluate both
demographic risks, such as low abundance and productivity, and threats
to the species including those related to the factors specified by the
ESA Section 4(a)(1)(A)-(E).
Methods
As we have explained, we convened an ERA team to evaluate
extinction risk to the species. This section discusses the methods used
to evaluate threats to each DPS and draw overall extinction risk
conclusions for each. As explained further down in this notice, we have
separately taken into account other conservation efforts which have the
potential to reduce threats identified by the ERA team.
For purposes of the risk assessment, an ERA team comprised of
fishery biologists and shark experts was convened to review the best
available information on the species and evaluate the overall risk of
extinction facing the scalloped hammerhead shark now and in the
foreseeable future. The term ``foreseeable future'' was defined as the
timeframe over which threats could be reliably predicted to impact the
biological status of the species. After considering the life history of
the scalloped hammerhead shark, availability of data, and type of
threats, the ERA team decided that the foreseeable future should be
defined as approximately 3 generation times for the scalloped
hammerhead shark, or 50 years. (A generation time is defined as the
time it takes, on average, for a sexually mature female scalloped
hammerhead shark to be replaced by offspring with the same spawning
capacity). This timeframe (3 generation times) takes into account the
time necessary to provide for the conservation and recovery of the
species. As a late-maturing species, with slow growth rate and low
productivity, it would likely take more than a generation time for any
conservative management action to be realized and reflected in
population abundance indices (as evidenced by the slow recovery of the
NW Atlantic & GOM DPS discussed below).
In addition, the foreseeable future timeframe is also a function of
the reliability of available data regarding the identified threats and
extends only as far as the data allow for making reasonable predictions
about the species' response to those threats. The ERA team considered
extending foreseeable future out to 100 years as well, but after
discussion, agreed that
[[Page 20726]]
they could not reliably predict the severity of threats, such as
overutilization or inadequacy of regulatory measures, with any
certainty past 50 years, given the changing nature of international and
national fishery management and push towards conservation and control
of illegal fishing. (As an aside, the timeframe of 3 generations is a
widely used scientific indicator of biological status, and has been
applied in decision making models by many other conservation management
bodies, including the American Fisheries Society, the CITES, and the
IUCN.)
Often the ability to measure or document risk factors is limited,
and information is not quantitative or very often lacking altogether.
Therefore, in assessing risk, it is important to include both
qualitative and quantitative information. In previous NMFS status
reviews, Biological Review Teams have used a risk matrix method to
organize and summarize the professional judgment of a panel of
knowledgeable scientists. This approach is described in detail by
Wainright and Kope (1999) and has been used in Pacific salmonid status
reviews as well as in the status reviews of many other species (see
http://www.nmfs.noaa.gov/pr/species/ for links to these reviews). In
the risk matrix approach, the collective condition of individual
populations is summarized at the DPS level according to four
demographic risk criteria: Abundance, growth rate/productivity, spatial
structure/connectivity, and diversity. These viability criteria,
outlined in McElhany et al. (2000), reflect concepts that are well-
founded in conservation biology and that individually and collectively
provide strong indicators of extinction risk.
Using these concepts, the ERA team estimated the extinction risk of
each scalloped hammerhead shark DPS based on current and future
demographic risks by assigning a risk score to each of the four
demographic criteria. The scoring for the risk criteria correspond to
the following values: 1--no or very low risk, 2--low risk, 3--moderate
risk, 4--high risk, and 5--very high risk. Likewise, the ERA team
performed a threats assessment for each DPS by scoring the severity of
current threats to the DPS as well as predicting whether the threat
will increase, decrease, or stay the same in the foreseeable future.
Detailed definitions of these risk scores can be found in the status
review report. The scores were tallied (mode, median, range), reviewed
by the ERA team, and considered in making the overall risk
determination. Although this process helps to integrate and summarize a
large amount of diverse information, there is no simple way to
translate the risk matrix scores directly into a determination of
overall extinction risk. Other descriptive statistics, such as mean,
variance, and standard deviation, were not calculated as the ERA team
felt these metrics would add artificial precision or accuracy to the
results.
Guided by the results from the demographics risk analyses as well
as the threats assessment, the ERA team members were asked to use their
informed professional judgment to make an overall extinction risk
determination for each DPS now and in the foreseeable future. For this
analysis, the ERA team again defined five levels of extinction risk:
1--no or very low risk, 2--low risk, 3--moderate risk, 4--high risk,
and 5--very high risk: however, the definitions differ slightly from
those used in the demographic and threats assessment, and can be found
in the status review report. To allow individuals to express
uncertainty in determining the overall level of extinction risk facing
the species, the ERA team adopted the ``likelihood point'' (FEMAT)
method. This approach has been used in previous NMFS status reviews
(e.g., Pacific salmon, Southern Resident killer whale, Puget Sound
rockfish, Pacific herring, and black abalone) to structure the team's
thinking and express levels of uncertainty when assigning risk
categories. For this approach, each team member distributed 10
`likelihood points' among the five levels of risks. The scores were
then tallied (mode, median, range) and summarized for each DPS.
Finally, the ERA team did not make recommendations as to whether
the species should be listed as threatened or endangered. Rather, the
ERA team drew scientific conclusions about the overall risk of
extinction faced by each DPS under present conditions and in the
foreseeable future based on an evaluation of the species' demographic
risks and assessment of threats.
Demographic Data Reviewed by the ERA Team
The amount of available data on scalloped hammerhead shark
abundance and trends varies by DPS. The abundance status of the NW
Atlantic & GOM DPS is likely the best understood, with over 2 decades
of data available from multiple recreational and commercial sources and
analyzed in a recent stock assessment by Hayes et al. (2009).
Recreational catch data used in this stock assessment were collected by
the NMFS Marine Recreational Fishery Statistics Survey, NMFS' Southeast
Region Headboat Survey, and the Texas Parks and Wildlife Department
Marine Recreational Fishing Survey. These surveys have been in
operation since the early 1970s and provide estimates of total catch
data and CPUE data through random-dial telephone surveys, dockside
intercept sampling programs, and self-reported logbook or daily catch
record surveys. As these surveys do not provide data to estimate catch
in biomass, the recreational survey data was only analyzed in terms of
numbers of individual sharks. Commercial catch data used in the stock
assessment were collected by the NMFS Southeast Fisheries Science
Center from the Pelagic Dealer Compliance database and from the
Accumulated Landings Systems. Landings weights were converted into
catch numbers by dividing the weight by an average weight of the
individual animal as reported in the Commercial Shark Fishery Observer
Program. In this way, recreational and commercial catch numbers could
be directly compared. Discard estimates specifically for scalloped
hammerheads are not available before 1987 or after 2001 (due to S.
lewini being lumped into a larger dealer report category), so estimates
for these years were based on average discards in 1987-1992 and 1993-
2001, respectively. Additionally, no catch was assumed to take place
prior to 1981 based on insufficient catch data available before that
year. This assumption was tested through sensitivity analyses and
subsequently accepted by Hayes et al. (2009).
For the stock assessment, indices of relative abundance from
fishery-dependent and -independent data were estimated for inclusion in
surplus-production models to determine population projections and
rebuilding probabilities. Fishery dependent indices were estimated
through CPUE data provided by commercial fishery logbooks and observer
programs and standardized according to the Lo method (Lo et al., 1992).
Fishery-independent surveys are less biased indices of abundance and
were included in the models after standardization. Fishery-independent
surveys are assumed to more accurately reflect population abundance due
to their standardized sampling methods that are designed not to target
specific concentrations of fish. The three fishery-independent surveys
that were included in the stock assessment models are: the NMFS
Pascagoula longline survey, which uses a standardized, random sampling
design stratified by depth and covering the western Gulf of Mexico to
North Carolina along the U.S.
[[Page 20727]]
southeastern Atlantic seaboard; the NMFS Panama city Gillnet Survey,
which uses a standardized sampling design, with monofilament gillnets
set at fixed stations monthly from April to October in shallow, coastal
areas of the northwestern Gulf of Mexico close to the Florida
panhandle; and the North Carolina longline survey, which uses a
standardized sampling design, with unanchored longlines set biweekly
off the central coast of North Carolina near Cape Lookout.
In addition to the stock assessment, the ERA team also considered
other data sources of abundance estimates. This included a study by
Ferretti et al. (2008), which provided historical records of shark
catches from the Mediterranean Sea; however, the ERA team had concerns
about the species-level identifications in the study. Some CPUE
information, providing long-term trends data, was available from beach
netting programs off the coasts of South Africa and Australia. The
methods and materials from these beach protection programs have largely
remained the same over the years, providing a good source of fishery-
independent data. In South Africa, the beach protection programs have
been in place since the early 1950s, providing catch rates of scalloped
hammerhead sharks off various beaches from 1952 to 2003. In Australia,
catch data from shark control programs off the coast of Queensland is
available from 1986 to 2010. Other data sources for abundance analyses
include: estimates of breeding individuals and pups from a scalloped
hammerhead nursery ground in Hawaii, diver sighting reports from 1992-
2004 in protected waters of the eastern Pacific, and estimates of the
rate of population decline in the Gulf of Tehuantepac, Mexico.
Growth and productivity analyses were primarily based on data
collected from scalloped hammerhead populations in the Atlantic Ocean
as there is some scientific disagreement on the aging methodology used
to interpret growth bands in studies on S. lewini from the Pacific
Ocean. Scalloped hammerhead sharks develop opaque bands on their
vertebrae, which are used to estimate age. For some studies conducted
in the eastern and western Pacific, band formation was assumed to occur
bi-annually, whereas in the Atlantic, bands were assumed to form
annually (see Miller et al., 2013). Although indirect age validation
studies for S. lewini are still inconclusive, bomb radiocarbon and
calcein methods (direct age validation methods) have been used to
validate annual growth bands for two other species of Sphyrna,
including the great hammerhead shark (S. mokarran) and the bonnethead
shark (S. tiburo) (Parsons, 1993; Passerotti et al., 2010). Therefore,
it seems more likely that the scalloped hammerhead shark undergoes
annual band formation, as has been found in other chondrichthyan growth
studies (Campana et al., 2002; Okamura and Semba, 2009), and this
assumption was used when examining age maturity, growth, and
productivity estimates.
For spatial structure/connectivity the ERA team considered the
current and historical range of the taxon and the habitat requirements
and physical characteristics of the habitat as documented in the
scientific literature. With respect to diversity, the ERA team examined
the genetic data, which provided estimates of migration rates per
generation, and analyzed any potential threats of genetic bottlenecking
or other ecological and human-caused factors that could substantially
alter the rate of gene flow in the DPS.
Evaluation of Demographic Risks
NW Atlantic & GOM DPS
A recent assessment for the northwest Atlantic and Gulf of Mexico
scalloped hammerhead shark stock concluded that the population has
declined by over 80 percent since 1981 (Hayes et al., 2009). Other
studies have also reported similar decreases in S. lewini populations
along the western Atlantic coast. For example, Baum et al. (2003)
calculated that the northwest Atlantic population of S. lewini has
declined 89 percent since 1986; however, this study is controversial
due to its reliance on only pelagic longline logbook data. Off the
southeastern U.S. coast, Beerkircher et al. (2002) observed significant
declines in nominal CPUE for S. lewini between 1981-1983 (CPUE = 13.37;
Berkeley and Campos, 1988) and 1992-2000 (CPUE = 0.48). On a smaller
scale, Myers et al. (2007) documented a 98 percent decline of the S.
lewini population off the coast of North Carolina between 1972 and
2003, using standardized CPUE data from shark targeted, fishery-
independent surveys. However, the authors also discovered a significant
increase in juvenile scalloped hammerheads (instantaneous rate of
change = 0.094) from 1989 to 2005. Comparing estimates of population
size off the coast of South Carolina, Ulrich (1996) reported a 66
percent decrease between 1983-1984 and 1991-1995. Although these
declines in former abundance numbers are significant, the latest stock
assessment for this DPS found that population numbers have remained
fairly stable since 1995 (Hayes et al., 2009). The stock assessment
also predicted a 91 percent probability of the population rebuilding
within 30 years under 2005 catch levels. From 2006 to 2010, the U.S.
scalloped hammerhead harvest has been below this 2005 catch level. In
addition, stronger management measures have been implemented in this
fishery, with a scalloped hammerhead shark rebuilding plan expected in
2013, which we believe will substantially contribute to continued
increases in abundance and stability of this DPS. As such, the ERA team
concluded, and we agree, that the future levels of abundance of the NW
Atlantic & GOM DPS alone are unlikely to contribute significantly to
its risk of extinction.
The ERA team also noted that sharks, in general, have lower
reproductive rates and growth rates compared to bony fishes. Estimates
for the intrinsic rate of increase (r) for scalloped hammerhead sharks
are relatively low, ranging from 0.028 to 0.121 (see Miller et al.,
2013), suggesting general vulnerability to depletion. But compared to
other chondrichthyan species, scalloped hammerhead sharks actually show
a moderate rebound potential to exploitation by pelagic longline
fisheries common in this DPS (Cort[eacute]s et al., 2010; ICCAT, 2012).
In addition, the ERA team did not see habitat structure or
connectivity as a potential risk to this DPS. Already, an extensive
range of essential fish habitat (EFH) has been identified for both
juveniles and adults of this DPS. EFH is the habitat necessary for
spawning, breeding, feeding, and growth to maturity for a species, and
NMFS, the regional fishery management councils, and other Federal
agencies work together to minimize threats to these identified EFH
areas. The current EFH for this DPS extends from the coastal areas in
the Gulf of Mexico from Texas to the southern west coast of Florida and
along the Atlantic U.S. southeast coast from Florida up to Long Island,
NY. Scalloped hammerhead sharks of all developmental stages have been
identified within this EFH range (NMFS, 2006), along the eastern
Atlantic and Gulf of Mexico coast, which suggests that habitat
connectivity does not appear to be a limiting factor in this DPS's
survival. Habitat structure also does not appear to be a threat, with
the sharks inhabiting a range of environments with varying complexity
(from estuaries to open oceans). Because the shark resides in the water
column, threats to changes in the physical characteristics of the water
column, such as salinity, temperature, and dissolved oxygen, may pose
the greatest
[[Page 20728]]
risk to this species. Estuaries and nearshore waters are especially
susceptible to pollution from anthropogenic impacts and subsequent
water quality degradation. However, the species is highly mobile with
no data to suggest it is restricted to any specific estuarine or
shallow coastal area for use as a habitat ground. In addition, the
degree to which habitat alterations have affected this shark species is
not currently known (NMFS, 2009). As such, the ERA team concluded, and
we agree, that habitat structure or connectivity is not a present risk
to this DPS.
Central & SW Atlantic DPS
The ERA team noted that specific abundance numbers for this DPS are
unavailable but likely similar to, and probably worse than, those found
in the NW Atlantic & GOM DPS, mainly due to the observed intensive
fishing pressure on this DPS. In the late 1990s, Amorim et al. (1998)
remarked that heavy fishing by longliners led to a decrease in this
population off the coast of Brazil. According to the FAO global capture
production database, Brazil reported a significant increase in catch of
S. lewini during this period, from 30 mt in 1999 to 508 mt by 2002,
before decreasing to a low of 87 mt in 2009. Documented heavy inshore
fishing has also led to significant declines of adult female S. lewini
abundance (up to 90 percent) (CITES, 2010) as well as targeted fishing
of and reported decreases in juvenile and neonate scalloped hammerhead
populations (Vooren et al., 2005; Kotas et al., 2008). Information from
surface longline and bottom gillnet fisheries targeting hammerhead
sharks off southern Brazil indicates declines of more than 80 percent
in CPUE from 2000 to 2008, with the targeted hammerhead fishery
abandoned after 2008 due to the rarity of the species (FAO, 2010). The
population abundance in the Caribbean is unknown as catch reporting is
sporadic and not normally recorded down to the species level.
However, unlike the NW Atlantic & GOM DPS, exploitation of this DPS
continues to go largely unregulated. In Central America, a lack of
resources has led to poor enforcement of fishery regulations as well as
frequent incidences of illegal fishing (further discussed in the
Inadequacy of Existing Regulatory Mechanisms section). In Brazilian
waters, there are very few fishery regulations that help protect
hammerhead populations. For example, the minimum legal size for a
scalloped hammerhead caught in Brazilian waters is 60 cm total length;
however, S. lewini pups may range from 38 cm to 55 cm. As the pup sizes
are very close to this minimum limit, the legislation is essentially
ineffective, and as such, large catches of both juveniles and neonates
have been documented from this region (Silveira et al., 2007; Kotas et
al., 2008; CITES, 2010). Although Brazil has implemented other measures
aimed at protecting species that use inshore areas as nursery grounds,
such as by limiting gillnets and closing off certain fishing areas,
unlike the management measures in the NW Atlantic & GOM DPS, these
regulations are poorly enforced. Because of the lack of enforced
fishery regulations, fishers continue to take large numbers of all ages
of scalloped hammerhead sharks from inshore and coastal waters of this
DPS. These threats, which have contributed to the decline in abundance
of this DPS, and will continue to do so into the foreseeable future,
are discussed in more detail below. Given the scalloped hammerhead
shark's low intrinsic productivity, the observed downward trends in
reported catches and population numbers, and continued threat from
bycatch and directed catch in weakly regulated commercial and
recreational fisheries, the ERA team concluded, and we agree, that the
DPS' current and future levels of abundance are likely to contribute
significantly to its risk of extinction.
Eastern Atlantic DPS
Abundance numbers for this DPS are unavailable or unreliable, but
population trends likely reflect those found in the NW Atlantic & GOM
DPS based on the similar fishing effort of longline fleets in this area
(Zeeberg et al. 2006; CITES, 2010). One study that the ERA team
reviewed used historical records to estimate declines of > 99.99
percent in both biomass and abundance of scalloped hammerhead sharks
over the past 100 years in the Mediterranean Sea (Ferretti et al.,
2008). However, the ERA team voiced concerns regarding the species
identification in the records, as many of the hammerheads found in the
Mediterranean Sea are actually the similarly-looking smooth, not
scalloped, hammerhead shark. Recently, Sperone et al. (2012) confirmed
the presence of both S. lewini and S. zyganea around southern Italy,
providing evidence that the species can still be found in the
Mediterranean Sea.
According to data provided to the FAO, S. lewini abundance off the
coast of Mauritania has declined by 95 percent since 1999, with
evidence of a decrease in average size of the shark since 2006 (FAO,
2013). Abundance trends from off the coast of other western African
countries are not available but likely similar to the situation off
Mauritania (FAO, 2013). The status of other stocks from this region may
also provide a likely picture of the scalloped hammerhead shark
population in this region. According to the latest FAO report on the
State of World Fisheries and Aquaculture, most of the pelagic stocks
and demersal fish from the Eastern Central Atlantic are considered
fully exploited to overexploited (FAO, 2012). In addition, many of the
shrimp stocks range between fully and overexploited and the
commercially important octopus and cuttlefish stocks in this region are
deemed overexploited. Some stocks, such as the white grouper in Senegal
and Mauritania, are even considered to be in severe condition. Driving
this exploitation is the increasing need for protein resources in this
region, both as a trade commodity and as a dietary staple. In fact,
many people in Sub-Saharan Africa depend on fish for protein in their
diet, with fish accounting for around 22 percent of their protein
intake (Heck and B[eacute]n[eacute], 2005). This proportion increases
to over 50 percent in many of the poorer African countries, where other
animal protein is scarce, and in West African coastal countries, where
fishing has driven the economy for many centuries (Heck and
B[eacute]n[eacute], 2005). For example, fish accounts for 47 percent of
protein intake in Senegal, 62 percent in Gambia, and 63 percent in
Sierra Leone and Ghana (Heck and B[eacute]n[eacute], 2005). With this
reliance on fish stocks for dietary protein as well as a sole source of
income for many people in this region, it is not surprising that the
FAO reports that ``the Eastern Central Atlantic has 43 percent of its
assessed stocks fully exploited, 53 percent overexploited and 4 percent
non-fully exploited, a situation warranting attention for improvement
in management.'' (FAO, 2012)
With evidence to suggest that large artisanal fisheries are taking
substantial amounts of juvenile scalloped hammerhead sharks from these
waters, and reports of fisheries even specializing in catching sphyrnid
species (CITES, 2010), it is highly likely that this DPS' status is
similar to the status of other fish stocks in this region (i.e., fully
to overexploited). Thus, taking into consideration the species' low
intrinsic rate of productivity, the largely unregulated catch of the
species off West Africa with indications of abundance declines and
possible size truncation, threats from overexploitation and poor
management,
[[Page 20729]]
and the rising demand for food/protein in this region (projected to
double by 2020; World Bank, 2012), the ERA team concluded, and we
agree, that future abundance levels of this DPS are likely to
contribute significantly to its risk of extinction. These threats,
which have contributed to the decline in abundance of this DPS, and
will continue to do so into the foreseeable future, are discussed in
more detail below.
Indo-West Pacific DPS
Beach protection programs in the Indo-West Pacific region have
provided valuable fishery-independent data that reveal drastic declines
in this scalloped hammerhead shark population since the early 1950s.
Specifically, declines of 99 percent, 86 percent, and 64 percent have
been estimated for S. lewini from catch rates in shark nets deployed
off the beaches of South Africa from 1952-1972, 1961-1972, and 1978-
2003, respectively (Dudley and Simpfendorfer, 2006; Ferretti et al.,
2010). Estimates of the decline in Australian hammerhead abundance
range from 58-85 percent (Heupel and McAuley 2007; CITES, 2010). CPUE
data from the northern Australian shark fishery indicate declines of
58-76 percent in hammerhead abundance in Australia's northwest marine
region from 1996-2005 (Heupel and McAuley, 2007). Data from protective
shark meshing programs off beaches in New South Wales (NSW) and
Queensland also suggest significant declines in hammerhead populations
off the east coast of Australia. From 1973 to 2008, the number of
hammerheads caught per year in NSW beach nets decreased by more than 90
percent, from over 300 individuals to fewer than 30 (Reid and Krogh,
1992; Williamson, 2011). Similarly, data from the Queensland shark
control program indicate declines of around 79 percent in hammerhead
shark abundance between the years of 1986 and 2010, with S. lewini
abundance fluctuating over the years but showing a recent decline of 63
percent between 2005 and 2010 (QLD DEEDI, 2011). Although these studies
provide evidence of declining local populations, there is a high degree
of uncertainty regarding the overall population size given the
expansive range of this DPS.
Additionally, the ERA team noted that the coastal habitats of this
DPS, especially around the island nations of the western Pacific, are
less connected than those of the other DPSs that have a contiguous
coastline. But since the western Pacific islands are relatively close
together or connected by various submarine features, the ERA team felt
that these areas are easily accessible to this DPS and therefore should
pose minimal ecological risk. Overall, the ERA team recognized that the
total abundance for this species in the entire region is not well
known, but the available data confirm localized depletions of
populations. This information, coupled with the species' low intrinsic
rate of productivity, led the ERA team to conclude that the abundance
in the foreseeable future may decline to a level that would not provide
the DPS adequate resilience to environmental or anthropogenic
perturbations. We agree with the ERA team's findings.
Central Pacific DPS
Abundance in this DPS is perceived to be high based on shark pup
data from this region as well as personal observations from NMFS
fishery scientists in the Pacific Islands Fishery Science Center. In
K[amacr]ne`ohe Bay, a large nursery ground in Oahu, Hawaii, estimates
of 7700 2240 SD scalloped hammerhead sharks are born per
year, which suggests that between 180 and 660 adult female sharks use
this area annually as a birthing ground (Duncan and Holland, 2006).
Growth rate of these pups is estimated to be 9.6 cm per year (Duncan
and Holland, 2006). Although Clarke (1971) observed high predation on
the pups by adult scalloped hammerheads, the author noted that the pup
population remained high and suggested that either the pup population
is significantly larger than previously thought, or that new births are
compensating for the mortality of the pups in this nursery ground.
With respect to spatial structure and connectivity, this DPS has a
high degree of isolation. However, while the population is limited in
its connection to other coastal habitat areas, the fragmented habitats
that are within this DPS are traversable, connected by various
submarine features like seamounts and guyots. In addition, a number of
suitable nursery grounds have been identified within this DPS. Thus,
although the isolation of the DPS in the middle of the Pacific Ocean
may pose a moderate risk to the species, the ERA team concluded, and we
agree, that high abundance numbers and ample suitable nursery habitats
protect the scalloped hammerhead shark population from extinction, with
current levels of abundance unlikely to contribute significantly to
this DPS' risk of extinction now or in the foreseeable future.
Eastern Pacific DPS
The ERA team commented that there are few good abundance data from
this region; however, reports of substantial legal and illegal takes of
S. lewini, and observed declines in scalloped hammerhead abundance and
overall shark abundance, including in protected waters, suggest
significant reductions in abundance of this species. Scalloped
hammerhead sharks of all age classes are caught in substantial numbers
by fisheries operating in this region (Perez-Jimenez et al., 2005;
Rom[aacute]n-Vedesoto and Orozco-Z[ouml]ller 2005; INP, 2006; Bizarro
et al., 2009; Arriatti, 2011). Some artisanal fisheries primarily
target juvenile S. lewini (Arriatti, 2011), while other fisheries, like
the tuna purse seine fisheries, catch significant numbers of the sharks
as bycatch (Rom[aacute]n-Vedesoto and Orozco-Z[ouml]ller, 2005). In the
Gulf of Tehuantepac, in Pacific southeastern Mexico, it is estimated
that the scalloped hammerhead population is currently decreasing by 6
percent per year (INP, 2006). From 1996-2001, CPUE of all sharks in the
Gulf of Tehuantepac declined by around 46 percent, and for S. lewini,
CPUE declined to nearly zero in 2001 (INP, 2006). Farther south, in the
Costa Rica EEZ, analysis of survey research and catch data from 1991-
1992 and 1999-2000 indicate a decline of 58 percent in relative pelagic
shark abundance (Arauz et al., 2004). In Costa Rica's Pacific mahi-mahi
targeted longline fishery, the mean CPUE (per 1,000 hooks) of S. lewini
between 1999 and 2008 was low (0.041 0.279); however, the
majority of the fishing effort was concentrated in pelagic waters (from
19.5 to 596.2 km offshore) (Whoriskey et al., 2011). More troubling are
the diver reports of S. lewini populations in the protected waters
around Cocos Island National Park. Analysis of these reports indicate
declines of 71 percent in this protected S. lewini population, and
suggest substantial fishing on this population by illegal, unreported,
and unregulated (IUU) fishing vessels (Myers et al., n.d.).
Furthermore, landings data from the Pacific Mexican coast suggest a
possible size truncation of this S. lewini population, with larger
animals less common in 2007-2009 landings compared to those from 1998-
1999 (Bizarro et al., 2009). The removal of larger, and hence, likely
mature animals can decrease the productivity of the population,
particularly for slow-growing, long-lived species such as the scalloped
hammerhead shark. From an evolutionary standpoint, Nance et al. (2011)
calculated that this DPS has undergone significant declines (1-3
[[Page 20730]]
orders of magnitude) from its ancestral population, with the onset of
decline occurring approximately 3600 to 12,000 years ago. Thus, given
the observed decreases in population and possible size truncation, low
intrinsic productivity of the species, and evidence of significant
legal and illegal fishing of this DPS, suggesting a need for better
fisheries management or enforcement, the ERA team concluded, and we
agree, that the current abundance may be at a level that contributes
significantly to the DPS' risk of extinction now and in the foreseeable
future. These threats (significant legal and illegal fishing), which
have contributed to the decline in abundance of this DPS, and will
continue to do so into the foreseeable future, are discussed in more
detail below.
Summary of Factors Affecting the Six DPSs of Scalloped Hammerhead
Sharks
As described above, section 4(a)(1) of the ESA and NMFS
implementing regulations (50 CFR 424) state that we must determine
whether a species is endangered or threatened because of any one or a
combination of the following factors: (1) The present or threatened
destruction, modification, or curtailment of its habitat or range; (2)
overutilization for commercial, recreational, scientific, or
educational purposes; (3) disease or predation; (4) inadequacy of
existing regulatory mechanisms; or (5) other natural or man-made
factors affecting its continued existence. The ERA team evaluated
whether and the extent to which each of the foregoing factors
contributed to the overall extinction risk of the six DPSs. The status
report identifies the most serious individual threat(s) to a DPS'
persistence. It also identifies those threats that, in combination with
others, were thought to contribute significantly to the risk of a DPS'
extinction. This section briefly summarizes the ERA team's findings and
our conclusions regarding threats to scalloped hammerhead sharks with
occasional focus on threats specific to individual DPSs. More details
can be found in the status review report (Miller et al., 2013).
The Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range
The ERA team identified habitat destruction as a potential threat
to the scalloped hammerhead shark, but did not find evidence to suggest
that it is presently contributing significantly to any of the DPS's
risks of extinction. Currently, scalloped hammerhead sharks are found
worldwide, residing in coastal warm temperate and tropical seas and
rarely in waters cooler than 22 [deg]C (Compagno, 1984; Schulze-Haugen
and Kohler, 2003). They occur over continental and insular shelves and
adjacent deep waters, but can also be found in intertidal and surface
waters and depths of up to 450 to 512 m (Sanches, 1991; Klimley, 1993).
Estuaries and coastal embayments have been identified as particularly
important nursery areas for scalloped hammerhead sharks range wide,
while offshore waters contain important spawning and feeding areas. The
vertical habitat of scalloped hammerheads in the Gulf of California may
extend even farther to include areas of cold hypoxic waters (Jorgensen
et al., 2009), indicating an ability to tolerate large fluctuations in
temperature and dissolved oxygen concentrations.
In the U.S. EEZ, the MSA requires NMFS to identify and describe EFH
in FMPs, minimize the adverse effects of fishing on EFH, and identify
actions to encourage the conservation and enhancement of EFH. Towards
that end, NMFS has funded two cooperative survey programs intended to
help delineate shark nursery habitats in the Atlantic and Gulf of
Mexico. The Cooperative Atlantic States Shark Pupping and Nursery
Survey and the Cooperative Gulf of Mexico States Shark Pupping and
Nursery Survey are designed to assess the geographical and seasonal
extent of shark nursery habitat, determine which shark species use
these areas, and gauge the relative importance of these coastal
habitats for use in EFH determinations. Results from the surveys
indicate the importance of estuarine, nearshore, and coastal waters of
South Carolina, Georgia, Atlantic Florida, Florida Panhandle, and
Alabama as potential nursery habitats for scalloped hammerhead sharks
along the eastern U.S. Coast and Gulf of Mexico. Since the scalloped
hammerhead EFH is defined as the water column or attributes of the
water column, NMFS determined that there are minimal or no cumulative
anticipated impacts to the EFH from gear used in HMS and non-HMS
fisheries, basing its finding on an examination of published literature
and anecdotal evidence (NMFS, 2006).
Likewise, scalloped hammerhead shark habitat in the other DPSs is
similar to what is found in the NW Atlantic & GOM DPS, characterized
primarily by the water column attributes. For example, Zeeberg et al.
(2006) noted an increase in abundance of hammerhead bycatch in pelagic
trawlers operating in the Mauritania EEZ during the summer months,
which suggested frequent use of these waters as habitat areas by
scalloped hammerheads. However, bycatch probability decreased
significantly during the winter and spring, as trade wind-induced
upwellings caused sea surface temperatures to drop from summer maximums
of 30 [deg]C to 18 [deg]C, indicating sea surface temperature as a
significant habitat determinant. Likewise, Bessudo et al. (2011) found
that the depth at which scalloped hammerhead sharks commonly swam
around Malpelo Island in the Eastern Pacific coincided with the
thermocline, the temperature-based transition layer between the mixed
layer at the surface and the deep water layer. The authors also
suggested that scalloped hammerhead seasonal movements to and from the
island of Malpelo are linked to oceanographic conditions, with seasonal
environmental signals triggering the migratory movements (Bessudo et
al., 2011).
To date, no studies have looked at habitat alteration effects on
scalloped hammerhead shark populations. However, any modifications
would most likely affect S. lewini nursery habitats as these waters are
usually shallower, located closer inshore, and thus are more
susceptible to anthropogenic inputs than the offshore habitats.
Examples of identified scalloped hammerhead pupping grounds include the
T[aacute]rcoles River in the Gulf of Nicoya, Guam's Apra Harbor,
K[amacr]ne`ohe Bay in Oahu, Hawaii, and coastal waters off Oaxaca,
Mexico and the Republic of Transkei. These waters are or may be used by
humans for a variety of purposes that often result in degradation of
these and adjacent habitats, posing threats, either directly or
indirectly, to the biota they support (NMFS, 2006). These effects,
either alone or in combination with effects from other activities
within the ecosystem, may contribute to the decline of the species or
degradation of the habitat. The ERA team specifically noted that the
increased industrialization seen within the scalloped hammerhead shark
range could result in loss of coastal and nearshore habitats and higher
pollutants in waters used by the scalloped hammerhead shark. For
example, in Costa Rica, the increased industrialization and subsequent
waste from commercial, industrial, and transportation activities, as
well as coffee production and cattle farming, has led to the
accumulation of heavy metals near the mouth of a river frequently used
as a scalloped hammerhead shark nursery ground (Zanella et al., 2009).
High
[[Page 20731]]
concentrations of heavy metals damage the epithelial gill cells of
sharks and cause respiratory system failure (de Boeck et al., 2002);
however, such effects to S. lewini have not yet been reported in this
area or elsewhere in the species' range. Although severe pollution and
the degradation of water quality may be serious threats to S. lewini
nursery and juvenile habitats range wide, the ERA team also noted that
this species usually prefers more turbid and murkier waters. Data from
K[amacr]ne`ohe Bay in Hawaii show that juvenile scalloped hammerheads
prefer to aggregate in deeper water during the day, where the habitat
is composed mainly of mud and silt (Duncan and Holland, 2006). Areas of
higher hammerhead shark abundance also corresponded to locations of
greater turbidity and higher sedimentation and nutrient flow (Duncan
and Holland, 2006). This was also true of scalloped hammerheads in the
Eastern Pacific, with large adult schools gathering on the sides of
islands where the current was strongest, and juvenile scalloped
hammerheads frequenting shallow, turbid waters at the mouth of rivers
(Garro et al., 2009; Zanella et al., 2009). As such, characteristics
usually associated with coastal habitat degradation (such as runoff,
siltation, eutrophication, etc.) could actually enhance some of the
habitat for this species to a degree, creating more sediment and
nutrient rich waters.
Because the scalloped hammerhead range is mainly comprised of open
ocean environments occurring over broad geographic ranges, large-scale
impacts such as global climate change that affect ocean temperatures,
currents, and potentially food chain dynamics, are most likely to pose
the greatest threat to this species. Additionally, the scalloped
hammerhead shark is highly mobile within the range of its DPS, and
there is no evidence to suggest its access to essential habitat is
restricted within any of the DPSs. It also does not participate in
natal homing, which would essentially restrict the species to a
specific nursery ground, but rather has been found utilizing
artificially enlarged estuaries as nursery habitats located 100 to 600
km from established nursery grounds (Duncan et al., 2006). Also, based
on a comparison of S. lewini distribution maps from 1984 (Compagno,
1984) and 2012 (Bester, n.d.), and current reports of scalloped
hammerhead catches in FAO fishing areas, there is no evidence to
suggest a range contraction for any DPS based on habitat degradation.
Overall, using the best available information, there is no evidence to
suggest there exists a present or threatened destruction, modification,
or curtailment of the scalloped hammerhead shark's habitat or range and
we conclude that it is unlikely that this factor is contributing on its
own or in combination with other factors to the extinction risk of any
of the six DPSs evaluated.
Overutilization for Commercial, Recreational, Scientific or Educational
Purposes
The ERA team identified overutilization for commercial and/or
recreational purposes as a moderate to major threat contributing to
extinction risk for all six scalloped hammerhead shark DPSs. Scalloped
hammerhead sharks are targeted by industrial, commercial, artisanal and
recreational fisheries, and caught as bycatch in many other fisheries,
including pelagic longline tuna and swordfish fisheries and purse seine
fisheries. Unfortunately, significant catches of scalloped hammerheads
have and continue to go unrecorded in many countries. In addition,
scalloped hammerheads are likely under-reported in catch records, as
many records do not account for discards (example: Where the fins are
kept but the carcass is discarded) or reflect dressed weights instead
of live weights. Also, many catch records do not differentiate between
the hammerhead species, or shark species in general, and thus species-
specific population trends for scalloped hammerheads are not readily
available. Thus, the lack of catch data on scalloped hammerhead sharks
makes it impossible to estimate rates of fishing mortality for many of
the DPSs, or conduct detailed quantitative analyses of the effects of
fishing on the scalloped hammerhead populations. Nonetheless, there is
little doubt that overfishing has played a major role in the decline of
scalloped hammerhead sharks, and many other shark species for that
matter, around the world (Lack and Sant, 2011).
Estimates of worldwide catches of sphyrnids are reported in the FAO
Global Capture Production dataset mainly at the family level, but a
select number of countries have reported down to the species level.
Total catches of the hammerhead family have increased since the early
1990s (prior years were not reported), from 377 mt in 1991 to a current
peak of 5,786 mt in 2010. This rise is in contrast to the catches of S.
lewini, which have decreased, for the most part, since reaching a
maximum of 798 mt in 2002, suggesting a possible decline in population
abundance. However, only seven countries have reported S. lewini data
in this FAO database, which is by no means an accurate representation
of worldwide S. lewini landings data. Additionally, these FAO data do
not include discard mortalities. In order to gain a better estimate of
the global shark catch, the ERA team reviewed a study by Clarke et al.
(2006a, 2006b), which analyzed 1999-2001 Hong Kong fin trade auction
data in conjunction with species-specific fin weights and genetic
information. Scalloped hammerhead sharks are popular in the
international fin trade due to their large fins with a high fin needle
content (a gelatinous product used to make shark fin soup), and
subsequently fetch a high commercial price (Abercrombie et al., 2005).
These fins are found under the second most traded fin category in the
Hong Kong market. Applying a Bayesian statistical method to the trade
auction data, it was estimated that between 1 and 3 million smooth and
scalloped hammerhead sharks, with an equivalent biomass of 60-70
thousand mt, are traded annually (Clarke et al., 2006b). These
estimates are significantly higher than the catches reported to FAO,
and suggest that FAO catch data should only be used as coarse
estimates. To put these numbers into perspective, Hayes et al. (2009)
estimated the virgin, or unfished, population size (in 1981) of the
Northwest Atlantic and Gulf of Mexico scalloped hammerhead stock to be
in the range of 142,000--169,000 individuals.
Given the high exploitation rates and vulnerability of the
scalloped hammerhead shark to overfishing, the ERA team identified
overutilization, especially for the international fin trade, as the
most severe threat to the global scalloped hammerhead shark population.
With respect to each DPS, the severity of this threat to its risk of
extinction is briefly explained below.
NW Atlantic & GOM DPS
The ERA team identified the threat of overutilization by commercial
and recreational fisheries as a moderate risk to the extinction of the
NW Atlantic & GOM DPS of scalloped hammerhead sharks, but projected the
threat to decrease in the foreseeable future. In the Atlantic U.S.,
scalloped hammerhead sharks are considered a highly migratory species
(HMS), with this DPS managed as part of the U.S. Atlantic HMS
fisheries. These scalloped hammerhead sharks are mainly caught by
directed shark permit holders using bottom longline gear. To a lesser
degree they are caught as bycatch in longline and coastal gillnet
fisheries. In the recreational fisheries sector, scalloped
[[Page 20732]]
hammerheads became a popular target species of fishers in the last
several decades following the release of the movie ``Jaws'' (Hayes et
al., 2009). Data from multiple sources indicate that the NW Atlantic &
GOM DPS has experienced severe declines over the past few decades. It
is likely that these scalloped hammerhead sharks were overfished
beginning in the early 1980s and experienced periodic overfishing from
1983 to 2005 (Jiao et al., 2011).
In October 2009, Hayes et al. (2009) produced a stock assessment
for the U.S. Northwest Atlantic and Gulf of Mexico population of
scalloped hammerhead sharks, which NMFS reviewed and deemed appropriate
for the basis of U.S. management decisions. The stock assessment
incorporated both recreational and commercial catch information as well
as discard estimates since 1981, and developed abundance indices from
fishery-dependent and -independent surveys. From 1981-1990, a total of
181,544 scalloped hammerhead sharks from the NW Atlantic & GOM DPS were
estimated as caught, primarily by recreational fishers. In fact, the
recreational fishery sector accounted for over 90 percent of this
harvest. However, as the demand for shark products grew (including
meat, cartilage, and the highly prized fins), so did the commercial
shark fishery in the Atlantic, which saw expansion throughout the late
1970s and the 1980s (NMFS, 2006). Specifically, tuna and swordfish
vessels started to retain a greater proportion of their shark
incidental catch, and some directed fishery effort expanded as well.
Subsequently, catches accelerated through the 1980s and shark stocks,
especially the scalloped hammerhead shark, began to show signs of
decline (NMFS, 2006). After 1993, the estimated harvest of scalloped
hammerhead sharks decreased dramatically from 22,330 to 4,554
individuals; however, it should be noted that it was at this time when
NMFS implemented an FMP for Sharks of the Atlantic Ocean. Due to the
concern over the possibility of the Atlantic shark resource being
overfished, the 1993 Shark FMP established quotas, monitoring measures,
and a rebuilding plan for the large coastal shark fishery (NMFS, 1993).
In the following years, NMFS continued to revise these quotas based on
the latest stock assessment data, and developed stronger management
measures for the fishery, which likely explains the decrease in catch
of scalloped hammerhead sharks. Since 1993, the harvest of scalloped
hammerhead sharks has remained below 7,800 individuals, with the
average annual harvest of this DPS from 1995-2005 only about a quarter
of the pre-1990 levels (Hayes et al., 2009).
Using two forms of a surplus-production model, a logistic
(Schaefer, 1954) and Fox (1970) model, Hayes et al. (2009) calculated
annual fishing mortality (F), maximum sustainable yield (MSY), and the
size (N) of both the unfished and fished scalloped hammerhead shark
population in the U.S. Northwest Atlantic and Gulf of Mexico. Both
models showed that overfishing is likely occurring (F >
FMSY) with a greater than 95 percent probability that the
population is overfished (N < NMSY). The logistic model
estimated a population size in 2005 to be 35 percent (CI = 19-87
percent) of the population at MSY, with an estimated F of 114 percent
(CI = 43-397 percent) of FMSY, whereas the Fox model
estimated the population size to be 45 percent (CI = 18-89 percent) of
NMSY and F to be 129 percent (CI = 54-341 percent) of
FMSY. Both models estimated a depletion of around 83 percent
from the virgin population size (in 1981). However, under a constant
catch at the 2005 harvest level, the probability that the stock of
scalloped hammerheads will rebuild within 30 years was estimated to be
91 percent (with rebuilding defined as reaching a population size
greater than NMSY).
Since 2005, the catches of this DPS have remained fairly low in all
U.S. fishery sectors. In the Atlantic HMS fishery, an average of 25
vessels landed 181 hammerhead sharks per year from 2005 to 2009 on
pelagic longline gear (based on logbook data). In bottom longline (BLL)
hauls, observed catches of scalloped hammerhead sharks have varied by
year. In 2007, 39 individuals were observed in the BLL catch. This
number increased to 539 individuals in 2009, and then dropped 1 year
later to 328, with S. lewini comprising <= 2.8 percent of the total
number of sharks caught in the BLL hauls. However, comparisons of these
catches should be made with caution, as the number of participating
vessels, hauls, and trips vary greatly by year. In the gillnet fishery,
the scalloped hammerhead shark is no longer a frequently caught bycatch
species. In 2010, 4 drift gillnet vessels were observed making 14 sets
on 8 trips. Out of the total 2,728 sharks caught during these trips,
scalloped hammerhead sharks comprised only 1.2 percent (n = 33). In the
sink gillnet fishery, 17 vessels were observed making 281 sets on 53
trips in 2010. A total of 3,131 sharks were caught, with scalloped
hammerhead sharks comprising only 0.6 percent of this total (n = 19)
(Passerotti et al., 2011). Recreational harvest of scalloped hammerhead
sharks has also seen a decrease from the 1980s and early 1990 numbers,
likely due to the establishment of bag limits beginning in 1993, and
regulations limiting this fishery to only rod and reel and handline
gear in 2003.
The ERA team ranked the threat of overutilization as a moderate
risk, one that would contribute significantly to risk of extinction
only in combination with other factors, such as low and decreasing
abundance or inadequate regulatory mechanisms. However, given the
increase in management of the fishery since the early 1990s, the
subsequent infrequent occurrence of the species in fishing gear, the
stable abundance numbers, and the fact that both the U.S. commercial
and recreational harvest of this DPS have been below the recommended
rebuilding catch levels since 2005 (which will allow abundance levels
to increase in the foreseeable future), the ERA team concluded, and we
agree, that the available data suggest that the current threat of
overutilization by commercial and recreational fisheries has been
greatly reduced, minimized by the effectiveness of the existing fishery
management measures, and by itself will not contribute significantly to
this DPS' risk of extinction in the foreseeable future.
Central & SW Atlantic DPS
The ERA team identified the threat of overutilization by
industrial/commercial fisheries as a high risk and overutilization by
artisanal fisheries as a moderate risk to the extinction of the Central
& SW Atlantic DPS, with the threat projected to increase in the
foreseeable future. Brazil, the country that reports one of the highest
scalloped hammerhead landings in South America, maintains heavy
industrial fishing of this species off its coastal waters. In the ports
of Rio Grande and Itajai, annual landings of hammerhead sharks have
fluctuated over the years, but have reached significantly high numbers.
For example, in 1992, reported landings were approximately 30 mt but
increased rapidly to 700 mt in 1994. From 1995 to 2002, catches
decreased but fluctuated between 100-300 mt (Baum et al., 2007). FAO
global capture production statistics from Brazil show a significant
increase in catch of S. lewini, from 30 mt in 1999 to 262 mt in 2000.
In 2001 and 2002, catches almost doubled to 507 mt and 508 mt,
respectively, before decreasing to 87 mt in 2009.
[[Page 20733]]
High numbers of hammerhead sharks have also been removed by
longliners fishing off the coast of South America. Data from a tuna
fishery based in Santos City, S[atilde]o Paulo State, Brazil, revealed
that although longliners mainly target tuna, sharks have become popular
as incidental take (Amroim et al., 1998). In fact, from 1983-1994
Santos longliners began targeting sharks at least part of the time
during their trips, and by 1993, sharks comprised approximately 60
percent of the total longline catch. The total hammerhead yield
(includes S. lewini and S. zyganea) increased slightly from 1972 (7 mt)
to 1988 (79 mt), and then more significantly to a maximum of 290 mt in
1990 (as did the number of longliners catching sharks). During the
study period (from 1974-1997), S. lewini catch was reported throughout
the year and represented approximately 60 percent of the total
hammerhead yield. After 1990, hammerhead yield exhibited a decreasing
trend (to 59 mt in 1996), but this may have been a result of a change
in gear from traditional Japanese longline to monofilament longline
(Amorim et al., 1998). However, despite this change in gear, a follow-
up study conducted from 2007-2008 found that S[atilde]o Paulo State
longliners were still targeting sharks, and that the catch was
dominated by shark species (catch composition: Sharks = 49.2 percent,
swordfish = 35.5 percent, billfish, tuna, other = 15.3 percent) (Amorim
et al., 2011). By weight, hammerheads represented only 6.3 percent of
the total shark catch, or 37.7 mt, a decrease from the previously
reported yield in 1996. Of the 376 hammerhead sharks caught, 131 (or 35
percent) were S. lewini (Amorim et al., 2011).
S. lewini is also commonly landed by artisanal fishers in the
Central and Southwest Atlantic, with concentrated fishing effort in
nearshore and inshore waters, areas likely to be used as nursery
grounds. In the Caribbean, specific catch and landings data are
unavailable; however, S. lewini is often a target of artisanal
fisheries off Trinidad and Tobago and Guyana, and anecdotal reports of
declines in abundance, size, and distribution shifts of sharks suggest
significant fishing pressure on overall shark populations in this
region (Kyne et al., 2012). Additionally, Chapman et al. (2009)
recently linked S. lewini fins from Hong Kong fin traders to the
Central American Caribbean region, suggesting the lucrative fin trade
may partially be driving the artisanal and commercial fishing of this
DPS. Farther south, in Brazil, artisanal fisheries make up about 50
percent of the fishing sector, with many fishers focusing their efforts
inshore on schools of hammerheads. Between 1993 and 2001, adult female
S. lewini abundance in Brazil decreased by 60-90 percent due to this
inshore fishing pressure (CITES, 2010). In 2004, Brazil recognized this
threat of S. lewini overutilization in its waters and subsequently
added the species to its list of over-exploited species (Normative
Instruction MMA n[deg] 05); however, this listing does not carry with
it any prohibitions on fishing for the species. Thus, given the
available data on catch trends, yields, fishing effort, and fin trade
incentives, the ERA team concluded, and we agree, that the threat of
overutilization alone is likely to contribute significantly to risk of
extinction for the Central & SW Atlantic DPS.
Eastern Atlantic DPS
The ERA team identified the threat of overutilization by
industrial/commercial fisheries as a high risk to the extinction of the
Eastern Atlantic DPS, with the threat projected to increase in the
foreseeable future. Although species-specific data are unavailable from
this region, hammerheads are a large component of the bycatch in the
European pelagic freezer-trawler fishery that operates off Mauritania.
Between 2001 and 2005, 42 percent of the retained pelagic megafauna
bycatch from over 1,400 freezer-trawl sets consisted of hammerhead
species (S. lewini, S. zygaena, and S. mokarran) (Zeeberg et al.,
2006). Of concern, especially as it relates to abundance and
recruitment to the population, is the fact that around 75 percent of
the hammerhead catch were juveniles of 0.50-1.40 m in length (Zeeberg
et al., 2006).
In 2009, the European Union (EU) ranked second in the world for
landings of sharks, rays, and chimaeras (according to FAO catch
statistics), with landings estimated at 112,329 mt. The total amount of
hammerhead sharks landed was 227 mt, with Spanish vessels responsible
for 78 percent of the catch (178 mt), followed by Portugal (37 mt)
(Shark Alliance, 2012). Although these vessels fish all over the world,
they likely concentrate efforts in the Atlantic. In 2005, 85 percent of
the overall reported Spanish shark catches were from the Atlantic Ocean
(Shark Alliance, 2007), suggesting the Eastern Atlantic DPS of
scalloped hammerhead sharks may be at risk from overutilization by
these top EU shark fishing nations.
The threat of overutilization by artisanal fisheries was identified
as a moderate risk to the extinction of the scalloped hammerhead shark,
but is projected to increase under the weakly regulated and enforced
fisheries of West Africa to match the increasing demand for food/
protein in this region. In fact, estimates of per capita fish
consumption is expected to increase from 2011-2021 in all continents
except for Africa, where the population is growing faster than the
supply (FAO, 2012). In the Sub Regional Fisheries Commission (SRFC)
member countries (Cape-Verde, Gambia, Guinea, Guinea-Bissau,
Mauritania, Senegal, and Sierra Leone), the population is predicted to
increase from 35 million (in 2007) to around 76 million by 2050 (Diop
and Dossa, 2011). The fact that around 78.4 percent of the population
currently lives within 100 km of the coast means that there will likely
be higher demand and fishing pressure on marine resources as the
population continues to grow (Diop and Dossa, 2011). Already, around 96
percent of the fish stocks in the Eastern Central Atlantic are
considered fully to overexploited (FAO, 2012). Because many of these
West African countries depend on fish for dietary protein but also, as
it relates to scalloped hammerhead sharks, as a source of income, the
threat of overutilization is not likely to decrease.
According to FAO (2012), Africa is the continent with the highest
proportion of its fleet operating in inland waters (42 percent),
suggesting juveniles and neonates of this DPS may be in the most
danger. And, in fact, large artisanal fisheries in Mauritania have been
documented fishing great quantities of juvenile scalloped hammerhead
sharks using driftnets and fixed gillnets (CITES, 2010), with S. lewini
also caught in large numbers in the sciaenid fishery operating in this
region. In 2010, the first year that it provided capture production
statistics to FAO, Mauritania reported a total catch of 257 mt of S.
lewini, the highest amount reported by any one country since 2003.
According to Diop and Dossa (2011), shark fishing has occurred in
the SRFC member countries for around 30 years. Shark fisheries and
trade in this region first originated in Gambia, but soon spread
throughout the region in the 1980s and 1990s, as the development and
demand from the worldwide fin market increased. From 1994 to 2005,
shark catch reached maximum levels, with a continued increase in the
number of boats, better fishing gear, and more people entering the
fishery, especially in the artisanal fishing sector. Before 1989,
artisanal catch was less than 4,000 mt (Diop and Dossa, 2011). However,
[[Page 20734]]
from 1990 to 2005, catch increased dramatically from 5,000 mt to over
26,000 mt, as did the level of fishing effort (Diop and Dossa, 2011).
Including estimates of bycatch from the industrial fishing fleet brings
this number over 30,000 mt in 2005 (however, discards of shark
carcasses at sea were not included in bycatch estimates, suggesting
bycatch may be underestimated) (Diop and Dossa, 2011). In the SRFC
region, an industry focused on the fishing activities, processing, and
sale of shark products became well established. However, since 2005,
there has been a significant and ongoing decrease in shark landings,
with an observed extirpation of some species, and a scarcity of others,
such as large hammerhead sharks (Diop and Dossa, 2011), indicating
overutilization of the resource. From 2005 to 2008, shark landings
dropped by more than 50 percent (Diop and Dossa, 2011). In 2010, the
number of artisanal fishing vessels that landed elasmobranches in the
SRFC zone was estimated to be around 2,500 vessels, with 1,300 of those
specializing in catching sharks (Diop and Dossa, 2011).
Although species-specific data from this region are relatively
poor, due to the lack of detailed catch reporting in many of the
developing African countries, the ERA team concluded, and we agree,
that the available commercial information, observations on fishing
activities, and catch trends suggest that the threat of overutilization
alone is likely to contribute significantly to risk of extinction for
the Eastern Atlantic DPS.
Indo-West Pacific DPS
The ERA team identified the threat of overutilization by
industrial/commercial and artisanal fisheries as a high risk to the
extinction of the Indo-West Pacific DPS, with the threat projected to
increase in the foreseeable future. High levels of commercial fishing
that target sharks or catch them as bycatch occur in this DPS.
Unfortunately, few studies on the specific abundance of S. lewini have
been conducted in this DPS, making it difficult to determine the rate
of exploitation of this species. One study, off the coast of Oman,
found S. lewini to be among the most commonly encountered species in
commercial landings from 2002 to 2003 (Henderson et al., 2007).
However, in 2003, S. lewini experienced a notable decline in relative
abundance and, along with other large pelagic sharks, was displaced by
smaller elasmobranch species (a trend also reported by informal
interviews with fisherman) (Henderson et al., 2007). Off East Lombok,
in Indonesia, data provided to the FAO also suggest potential declines
in the population as the proportion of scalloped hammerheads in the
Tanjung Luar artisanal shark longline fishery catch decreased from 15
percent to 2 percent over the period of 2001 to 2011 (FAO, 2013).
Additionally, CPUE data from South Africa and Australia shark control
programs indicate significant declines (over 90 percent) of local
scalloped hammerhead populations in this DPS, most likely a result from
overharvesting, although it should be noted that these shark control
programs were also assessed to have at least a medium causative impact
on these localized depletions.
In other waters of this DPS, such as off the coasts of Maldives,
Kenya, Mauritius, Seychelles, and the United Republic of Tanzania,
shark populations are presumed to be fully to over-exploited (de Young,
2006). Likely contributing to the overexploitation of shark populations
is the vast number of tuna fisheries prevalent within the range of this
DPS, which are known to take substantial amounts of sharks as bycatch.
In the Republic of the Marshall Islands EEZ, the tuna fishery alone
accounted for annual longline catches ranging from 1,583 to 2,274 mt of
sharks (over the period of 2005-2009) (Bromhead et al., 2012). The tuna
purse seine fleet is also very active in this region and contributes to
the incidental catch of scalloped hammerhead sharks. The recent
addition of fleets entering the Western and Central Pacific Fishery
Commission (WCPFC) tropical fishery have brought the number of purse
seine vessels up to 280, the highest it has been since 1972 (Williams
and Terawasi, 2011). This is especially troubling given the species'
susceptibility to being caught in large numbers in purse seine nets
(Rom[aacute]n-Verdesoto and Orozco-Z[ouml]ller, 2005), although recent
WCPFC observer data suggest otherwise (SPC, 2010). In fact, the WCPFC
observer data, collected from 1994-2009, indicate that longline sets
may pose more of a threat to non-target shark species than purse-seine
sets in this convention area, but in terms of hammerhead sharks,
observers reported only negligible catch but with high rates of finning
in both types of sets (SPC, 2010). However, some fisheries operating in
the WCPFC Convention Area have not been observed, such as the Chinese
Taipei small scale tuna longline fleet, which reported a significant
catch of 365 mt (preliminary estimate) of scalloped hammerhead sharks
in the Convention Area in 2010 (Shark Year Magazine, 2011), and
suggests reliance on observer data alone may not be a good indicator of
scalloped hammerhead catch in this region.
Currently, the exact extent of fishing on this DPS by WCPFC vessels
is unknown, as the WCPFC has only just recently designated hammerheads
as key shark species for data collection (WCPFC, 2011) and many
Cooperating Commission Member (CMM) and Cooperating Non-Member fleets
have yet to provide this catch data, including fleets from among the
top 20 countries reporting Pacific shark catches to the FAO. As of
2012, the CMMs that reported specific catches of hammerheads from 2011
in the WCPFC convention area included Australia, Papua New Guinea,
Fiji, Chinese Taipei, and the European Union. The European Union
reported only negligible catch of hammerheads, with Fiji and Australia
reporting zero catches of scalloped hammerhead sharks. Papua New
Guinea, which currently has an active shark longline fishery that is
managed separately from its tuna longline fishery, reported catch from
its domestic shark fishery to the WCPFC. This shark fishery operates
entirely within Papua New Guinea's national waters, and is limited to 9
vessels, setting 1,200 hooks per day with a total allowable catch of
2,000 mt dressed weight per year (Usu et al., 2012). This fishery has
seen substantial expansion since 2000, when there was only one active
vessel with a reported catch of 143 sharks. However, in the last 4
years, an average of 7 vessels has actively fished for sharks, with an
average catch of 56,528 sharks (Usu et al., 2012). In 2011, there were
9 active shark longline vessels, reporting the highest overall effort
yet (27,934 hundred hooks), and subsequently reporting the highest
catches of sharks to date (1,479.66 mt) (Usu et al., 2012). Hammerhead
shark species comprised only 1.5 percent of the catch (22.34 mt), which
was a decrease of 43 percent from the previous year and suggests that
the intensive and targeted shark fishing effort may be contributing to
the hammerhead population decline in these waters.
Many fisheries in this region are also driven primarily by the
lucrative trade in shark fins. For example, in northern Madagascar,
Robinson and Sauer (2011) documented an artisanal fishery that targets
sharks primarily for their fins and discards the carcasses. Two shark
families comprised the majority of the artisanal landings:
Carcharhinidae accounted for 69 percent of the species and Sphyrnidae
accounted for 24 percent (Robinson and Sauer, 2011). S. lewini was the
most common species in
[[Page 20735]]
the Sphyrnidae landings. In addition, many of these fishers operated in
water shallower than 100 m and, consequently, over 96 percent of their
scalloped hammerhead catch was comprised of immature individuals
(Robinson and Sauer, 2011). Similarly, the shark fisheries operating in
Antongil Bay in northeastern Madagascar commonly land only fins, rather
than whole sharks, with the scalloped hammerhead shark as the most
represented species in the shark fishery (Doukakis et al., 2011). Both
adults, including pregnant females, and juveniles are harvested in the
small and large-mesh artisanal gillnet and traditional beach seine
fisheries, suggesting largely unregulated and targeted fishing of
scalloped hammerhead sharks in a potential breeding ground (Doukakis et
al., 2011).
Furthermore, four of the top five exporters of shark fins to Hong
Kong (Singapore, Taiwan, Indonesia, and the United Arab Emirates) are
located in this DPS' range. In 2008, these countries accounted for
around 34 percent (or 3,384 mt) of the total exports of shark fins
(both frozen and dried). Therefore, with the increased number of tuna
fleets, evidence of declines in shark catch and populations in this DPS
range, as well as the popularity of the scalloped hammerhead shark in
the fin trade, the ERA team agreed that the threat of overutilization
alone is likely to contribute significantly to the risk of extinction
of the Indo-West Pacific DPS.
Central Pacific DPS
The ERA team identified the threat of overutilization by
industrial/commercial fisheries as a moderate risk to the extinction of
the Central Pacific DPS, with the threat projected to remain the same
in the foreseeable future. Currently, scalloped hammerheads in this
region are mainly caught as bycatch by pelagic longline and purse seine
fleets. The Hawaii-based pelagic longline fishery has been in operation
since approximately 1917, and underwent considerable expansion in the
late 1980s to become the largest fishery in the state (Boggs and Ito,
1993). This fishery currently targets tunas and billfish and catches
are frequently documented by mandatory observers (100 percent coverage
for shallow-set sector and 25 percent for deep-set sector). From 1995-
2006, the observer data indicated a very low catch of scalloped
hammerhead sharks (56 individuals on 26,507 sets total, both fishery
sectors combined). More recent observer data (2009-2011) from this
fishery confirm that scalloped hammerhead sharks continue to be a very
rare catch, commensurate with the earlier time period (Walsh et al.,
2009; Walsh personal communication, 2012). In non-longline catch,
hammerhead shark species are also rare, with a total of 11 sharks
caught from 1990-1994 and 1995-1999, 6 caught from 2000-2004, 17 caught
from 2005-2009, and 6 caught from 2010-2011 (Seki and Kokubun personal
communication, 2012). Although the ERA team identified overutilization
by commercial fisheries as a threat, it ranked it as a moderate risk,
one that would contribute significantly to risk of extinction only in
combination with other factors, such as low and decreasing abundance or
inadequate regulatory mechanisms. We do not believe that the observed
low catch of this DPS is due to low population numbers since, as
previously mentioned, abundance is high in this area due in part to the
DPS' productive nursery grounds. Therefore, the low catch of S. lewini
is likely due to the strict management and regulation of these
commercial fisheries within this DPS range (see The Inadequacy of
Existing Regulatory Mechanisms section below). As such, we conclude
that the available data suggest that the threat of overutilization by
commercial fisheries is ameliorated by high population abundance and
effective existing management measures. We also agree with the ERA
team's finding that the adequacy of regulatory mechanisms in minimizing
the extinction risk of this DPS will only increase in the next 50
years, making it unlikely that the threat of overutilization will be a
greater risk to the DPS' continued existence in the foreseeable future.
Eastern Pacific DPS
The ERA team identified the threat of overutilization by
industrial/commercial fisheries and artisanal fisheries as a high risk
to the extinction of the Eastern Pacific DPS, with the threat projected
to increase in the foreseeable future. Although abundance data are
lacking in this area, information from commercial and artisanal
fisheries suggests heavy exploitation of this DPS. As an example, in
central Mexico, the shark fishery, which began in the early 1940s, grew
from catches of less than 5,000 mt in the early 1960s to catches of
25,000 mt in the late 1970s, and reached maximum exploitation in the
1980s and 1990s (P[eacute]rez-Jim[eacute]nez et al., 2005). During this
time, scalloped hammerheads were an important small shark species that
was routinely caught on the southern coast of Sinaloa (P[eacute]rez-
Jim[eacute]nez et al., 2005; Bizzarro et al., 2009). From 1998-1999,
scalloped hammerhead sharks comprised 54.4 percent of the elasmobranch
catch and 43.1 percent of the total recorded catch (n = 1,584 S. lewini
individuals) based on surveys from 28 Sinaloa artisanal fishing sites
(Bizzarro et al., 2009). In 2006, elasmobranch landings from this area
comprised 16.5 percent of the national elasmobranch production, the
most of any Mexican state, indicating S. lewini as a popular fished
species in the Mexican shark fishery. S. lewini is also an important
shark species in the artisanal fisheries operating elsewhere along the
Mexican Pacific coast. From 2004 to 2005, S. lewini comprised 64
percent of the artisanal shark catch south of Oaxaca, Mexico (CITES,
2012). In the Gulf of Tehuantepec, scalloped hammerhead sharks
constitute the second most important shark species targeted by Mexican
fishers, comprising around 29 percent of the total shark catch from
this region (INP, 2006). In fact, from 1996 to 2003, a total of 10,919
individual scalloped hammerhead sharks were landed from this area and
brought to port in the Mexican state of Chiapas (INP, 2006), where S.
lewini and C. falciformis represent 89.3 percent of the shark catch
(CITES, 2012).
In Ecuador, sharks are mainly caught as incidental catch in a
variety of fishing gear, including pelagic and bottom longlines, and
drift and set gill nets, with scalloped hammerheads used primarily for
the fin trade. A recent study by Jacquet et al. (2008) found that
Ecuadorian mainland shark landings have been grossly underestimated.
Through a reconstruction of catches by small-scale and industrial
fishers using government reports and grey literature, Jacquet et al.
(2008) estimated Ecuador mainland landings to be 6,868 mt (average) per
year from 1979-2004, with small-scale fisheries representing 93 percent
of the total landings. For the period of 1991-2004, the reconstructed
estimates were 3.6 times greater than what was reported to the FAO. For
the years following the study, Ecuadorian records from small-scale
fisheries show significantly lower catches of the hammerhead complex
and no clear trend. In 2004, total combined landings from ten of
Ecuador's main small-scale fishing ports were approximately 149 mt. In
2005, this number decreased by about 67 percent to 49 mt but
subsequently increased in the following years to reach a peak of 327 mt
in 2008. In 2009, landings decreased again by around 71 percent, but
tripled the following year to reach approximately 304 mt of hammerhead
sharks in 2010 (INP, 2010).
In Costa Rica, shark catches reported by the artisanal and longline
fisheries have shown a dramatic decline
[[Page 20736]]
(approximately 50 percent) after reaching a maximum of 5,000 mt in 2000
(SINAC, 2012). According to the Costa Rican Institute of Fishing and
Aquaculture, the estimated total catch of S. lewini by the coastal
artisanal and longline fleet from 2004-2007 was 823 mt, which
represented 3 percent of the national Costa Rican total catch of sharks
for these years (SINAC, 2012).
Of major concern is that many of the artisanal fishers from the
Eastern Pacific region are targeting schools of immature S. lewini due
to the profitability of the younger shark meat (Arriatti, 2011), and
likely negatively affecting recruitment to this DPS. In Panama,
directed artisanal fishing for hammerheads has been documented in
coastal nursery areas, with artisanal gillnet fishery catches dominated
by neonate and juvenile S. lewini (Arriatti, 2011). Likewise, in Costa
Rica, many of the identified nursery grounds for scalloped hammerheads
are also popular elasmobranch fishing grounds and are heavily fished by
gillnets (Zanella et al., 2009). From 2006 to 2007, artisanal fishers
operating in the Gulf of Nicoya (central Pacific coast of Costa Rica)
landed a total of 253 scalloped hammerhead sharks. The average total
length of these sharks ranged from 75.45-87.92 cm, significantly below
the maturity sizes that have been documented for this species (Zanella
et al., 2009). In ``Tres Marias'' Islands and Isabel Island in the
Central Mexican Pacific, Perez-Jimenez et al. (2005) found artisanal
fishery catches dominated by immature individuals. Out of 1,178 females
and 1,331 males caught from 1995-1996 and 2000-2001, less than 1
percent were mature (Perez-Jimenez et al., 2005). On the coast of
Chiapas in Mexico, neonates (<= 60cm TL) comprised over 40 percent of
the Port of Madero catch from 1996-2003 (INP, 2006). Seasonal surveys
conducted in Sinaloa, Mexico from 1998-1999 depict an active artisanal
fishery that primarily targets early life stages of S. lewini, with
only four specimens (out of 1,515) measuring > 200 cm stretched TL
(Bizzarro et al., 2009). A comparison of landing sizes from this region
between 1998-1999 and 2007-2008 revealed a significant decrease in S.
lewini size, indicating a possible truncation of the size of the local
population (Bizzarro et al., 2009). In Michoac[aacute]n, hammerheads
represent 70 percent of the catch, with fishing effort concentrated in
breeding areas and directed towards juveniles and pregnant females
(CITES, 2012) and reports of the artisanal fisheries filleting the
embryos of S. lewini for domestic consumption (Smith et al., 2009).
Overall, the data suggest heavy fishing pressure in scalloped
hammerhead nursery areas by artisanal fisheries, with substantial takes
of juveniles and neonates, and possibly pregnant females, of this DPS,
which is likely to have devastating effects on the stock structure and
size of the population, especially given the low productivity of the
species.
Large numbers of scalloped hammerhead sharks are also caught as
bycatch in industrial purse seine fisheries operating in the eastern
Pacific (Rom[aacute]n-Verdesoto and Orozco-Z[ouml]ller, 2005). Since
1993, observers placed by the Inter-American Tropical Tuna Commission
(IATTC) regional fishery management organization (RFMO) have recorded
shark bycatch data onboard large purse seiners in the eastern Pacific.
Unfortunately, much of this data is aggregated under the category of
``sharks,'' especially data collected prior to 2005. In an effort to
improve species identifications in these data, a 1-year shark
characteristics sampling program was conducted to quantify at-sea
observer misidentification rates. Rom[aacute]n-Verdesoto and Orozco-
Z[ouml]ller (2005) used the program results and IATTC observer field
notes to provide summaries of the spatial distributions, size
composition, and species identification of the IATTC-observed bycatch
of sharks in the eastern Pacific Ocean tuna purse-seine fishery. From
1993 to 2004, hammerhead sharks were caught in high numbers as bycatch
and were most susceptible to the floating-objects type of purse seine
set (Rom[aacute]n-Verdesoto and Orozco-Z[ouml]ller, 2005). From 2001 to
2003, their observed numbers in the tuna purse seine sets increased by
approximately 166 percent to reach a maximum of 1,898 individuals.
Although specific data on scalloped hammerhead numbers are unavailable,
results from the 1-year sampling program suggest that scalloped
hammerhead sharks may comprise around 54 percent of the total
hammerhead bycatch (Rom[aacute]n-Verdesoto and Orozco-Z[ouml]ller,
2005). The IATTC observer data also revealed that the majority of the
bycatch consisted of large hammerhead individuals (>150 cm TL).
Given the available data on catch trends and the heavy fishing
effort targeting both juveniles and adults of the species, the ERA team
concluded, and we agree, that the threat of overutilization by
industrial/commercial and artisanal fisheries alone was likely to
contribute significantly to risk of extinction for the Eastern Pacific
DPS.
Competition, Disease, and Predation
The ERA team also wanted to examine whether competition, disease,
and predation were potential threats to the scalloped hammerhead shark,
but after reviewing the available data, ranked these factors as ``no or
very low risks,'' meaning these factors are unlikely to contribute
significantly to any of the DPS' risk of extinction, either by
themselves or in combination with other factors. Scalloped hammerhead
sharks are apex predators and opportunistic feeders, with a diet
composed of a wide variety of items, including teleosts, cephalopods,
crustaceans, and rays (Compagno, 1984; Bush, 2003; J[uacute]nior et
al., 2009; Noriega et al., 2011). Although there may be some prey
species that have experienced population declines, no information
exists to indicate that depressed populations of these prey species are
negatively affecting the scalloped hammerhead shark abundance.
Additionally, discovery of a possibly cryptic species of Sphyrna sp.
was reported in the northwestern Atlantic (mainly from coastal North
Carolina, South Carolina, and Florida) and most recently in the western
South Atlantic (Southern Brazil) (Abercrombie et al., 2005; Quattro et
al., 2006; Pinhal et al., 2012). This cryptic species is closely
related to and morphologically very similar to the scalloped hammerhead
shark (S. lewini); however, little is known about the life history or
abundance of this species. Although it may compete for similar
resources as the scalloped hammerhead shark, there are currently no
available data to indicate it as a threat to the scalloped hammerhead
shark's existence.
Furthermore, no information has been found to indicate that disease
is a factor in scalloped hammerhead shark abundance. These sharks
likely carry a range of parasites, such as external leeches
(Stilarobdella macrotheca) and copepods (Alebion carchariae, A.
elegans, Nesippus crypturus, Kroyerina scotterum); however, they have
often been observed visiting parasite cleaning stations (Bester, n.d.)
and no data exist to suggest these parasites are affecting S. lewini
abundance.
Predation is also not thought to be a major threat to scalloped
hammerhead abundance numbers. The most significant predator on
scalloped hammerhead sharks is likely humans; however larger sharks,
including adult S. lewini, are known to prey upon injured or smaller
scalloped hammerheads. In K[amacr]ne`ohe Bay, Oahu, Clarke (1971)
observed high predation on pups by adult scalloped
[[Page 20737]]
hammerheads. Clarke (1971) also noted that the pup population remained
high and suggested that new births may compensate for pup mortalities.
Subsequently, Duncan and Holland (2006) examined mortality rates in
this bay and estimated juvenile attrition to be 0.85 to 0.93 for the
first year of life (includes both natural and fishing mortality, as
well as emigration), a relatively high rate for a nursery habitat.
However, the authors concluded that weight loss, and not predation,
significantly contributed to the high natural mortality of the shark
pups, and suggested the popularity of the nursery ground was due to its
value as a refuge from predation. In the northwestern Pacific, Liu and
Chen (1999) estimated a significantly lower attrition rate for age zero
S. lewini sharks (0.558/year), with natural mortality rates decreasing
even further to 0.279/year for sharks aged 1-15 years. The ERA team
noted that there are no major predators of adult scalloped hammerhead
sharks.
Based on the available data, we conclude that it is unlikely that
the threats of competition, disease, or predation is contributing on
its own or in combination with other factors to the extinction risk of
any of the six DPSs evaluated.
The Inadequacy of Existing Regulatory Mechanisms
The ERA team evaluated existing regulatory mechanisms to determine
whether they may be inadequate to address threats to each of the
scalloped hammerhead DPSs. Existing regulatory mechanisms may include
Federal, state, and international regulations. Below is a brief
description and evaluation of current and relevant domestic and
international management measures that affect each scalloped hammerhead
shark DPS. More information on these domestic and international
management measures can be found in the status review report (Miller et
al., 2013).
NW Atlantic & GOM DPS
The Atlantic HMS Management Division within NMFS develops
regulations for Atlantic HMS fisheries, and primarily coordinates the
management of Atlantic HMS fisheries in Federal waters (domestic) and
the high seas (international), while individual states establish
regulations for HMS in state waters. The NMFS Atlantic HMS Management
Division currently manages 39 species of sharks (excluding spiny
dogfish, which is managed jointly by the New England and Mid-Atlantic
Fishery Management Councils, and smooth dogfish, which will be managed
by the HMS Management Division) under the Consolidated HMS FMP (NMFS,
2006). The management of these sharks is divided into four species
groups: large coastal sharks (LCS), small coastal sharks (SCS), pelagic
sharks, and prohibited sharks. The LCS complex is further divided into
sandbar sharks and non-sandbar sharks, with different management
measures for each group. Scalloped hammerhead sharks are currently
managed within the non-sandbar LCS complex with established acceptable
biological catch levels to control harvest.
Every year, NMFS monitors the different commercial shark quota
complexes and will close the fishing season for each fishery after 80
percent of the respective quota has been landed or is projected to be
landed. The non-sandbar LCS commercial quota is split between the Gulf
of Mexico and the Atlantic regions. One way that NMFS controls and
monitors this commercial harvest is by requiring U.S. commercial
Atlantic HMS fishers who fish for or sell scalloped hammerhead sharks
to have a Federal Atlantic Directed or Incidental shark limited access
permit. These permits are administered under a limited access program,
and NMFS is no longer issuing new shark permits. Currently, 214 U.S.
fishers are permitted to target sharks managed by the HMS Management
Division in the Atlantic Ocean and Gulf of Mexico, and an additional
285 fishers are permitted to land sharks incidentally. A directed shark
permit allows fishers to retain 36 LCS, including scalloped hammerhead
sharks, per vessel per trip whereas an incidental permit allows
fisherman to retain up to 3 LCS, including scalloped hammerhead sharks,
per vessel per trip. These limits apply to all gear; however, starting
in 2011, pelagic longline fishers have been prohibited from retaining,
possessing, or landing any hammerhead sharks, including scalloped
hammerhead sharks, due to Recommendation 10-08 from the International
Commission for the Conservation of Atlantic Tunas (ICCAT) (76 FR 53652;
August 29, 2011). In addition to permitting and trip limit
requirements, logbook reporting or carrying an observer onboard may be
required for selected commercial fishers. The head may be removed and
the shark may be gutted and bled, but the shark cannot be filleted or
cut into pieces while onboard the vessel.
Scalloped hammerhead sharks may also be retained recreationally
with either rod and reel or handline gear. Scalloped hammerheads that
are kept in the recreational fishery must have a minimum size of 54
inches (4.5 feet) fork length, and only one shark, which could be a
scalloped hammerhead, may be kept per vessel per trip. When NMFS
implemented ICCAT's Recommendation 10-08, NMFS prohibited hammerhead
sharks, including scalloped hammerhead sharks, from being retained,
possessed, or landed by recreational fishermen if there is a tuna,
swordfish, or billfish onboard the vessel (76 FR 53652; August 29,
2011). Since 2008, recreational fishers have been required to land all
sharks with their head, fins, and tail naturally attached.
Individual state fishery management agencies have authority for
managing fishing activity in state waters, which usually extends from
zero to three nautical miles (5.6 km) off the coast in most cases, and
zero to nine nautical miles (16.7 km) off Texas and the Gulf coast of
Florida. In the case of federally permitted shark fishers, fishers are
required to follow Federal regulations in all waters, including state
waters, unless the state has more restrictive regulations. To aid in
enforcement and reduce confusion among fishers, in 2010, the Atlantic
States Marine Fisheries Commission, which regulates fisheries in state
waters from Maine to Florida, implemented a Coastal Shark Fishery
Management Plan that mostly mirrors the Federal regulations for sharks,
including scalloped hammerhead sharks. States in the Gulf of Mexico and
territories in the Caribbean Sea have also implemented regulations that
are mostly the same as the Federal regulations for sharks, including
scalloped hammerhead sharks. However, the state of Florida, which has
the largest marine recreational fisheries in the United States and the
greatest number of HMS angling permits, recently went even further than
Federal regulations to protect the scalloped hammerhead shark by
prohibiting the harvest, possession, landing, purchasing, selling, or
exchanging any or any part of a hammerhead shark (including scalloped,
smooth, and great hammerheads) caught in its waters (Florida Fish and
Wildlife Conservation Commission, effective January 1, 2012).
The ERA team determined, and we agree, that existing domestic
management measures implemented under U.S. Federal and state
authorities are adequate to substantially reduce the primary threats
contributing to the extinction risk of the NW Atlantic & GOM DPS. The
existing regulatory mechanisms, which strictly manage and control
exploitation of the species by commercial and recreational fisheries,
are likely to contribute significantly to stabilizing and increasing
abundance of
[[Page 20738]]
this DPS. Based on an analysis of recreational and commercial catch and
landings data from the early 1980s through 2005, the Hayes et al.
(2009) stock assessment showed that a total allowable catch (TAC) of
2,853 scalloped hammerhead sharks would allow for a greater than 70
percent probability of rebuilding the stock within 10 years, an 85
percent probability of rebuilding within 20 years, and a 91 percent
probability of rebuilding within 30 years. Under existing Federal shark
regulations, the average total scalloped hammerhead shark mortality
from 2006-2010 was less than this Hayes et al. (2009) TAC
recommendation, suggesting current regulatory measures are adequate to
protect the scalloped hammerhead shark from risk of extinction.
Furthermore, because NMFS made an ``overfished'' and ``overfishing''
status determination of the scalloped hammerhead stock (76 FR 23794;
April 28, 2011), it is mandated to implement additional conservation
and management measures by 2013, providing additional protection for
the scalloped hammerhead shark stock from overexploitation. Proposed
conservation efforts are evaluated below in accordance with ESA Section
4(b)(1)(A).
Although the ERA team considered the threat of inadequate
regulatory measures as a low risk to the extinction of this scalloped
hammerhead shark population, it expressed concerns about the level of
IUU fishing of this DPS. Since the mid-1990s, the U.S. Coast Guard has
documented Matamoros Mexican vessels illegally fishing in the area
surrounding South Padre Island, Texas (Brewster-Geisz and Eytcheson,
2005). The Mexican IUU fishers use gillnet and longline gear to catch
sharks for the fin trade, the majority of which are blacktips and
hammerheads. Based on data from 2000-2005, Brewster-Geisz and Eytcheson
(2005) estimated that Mexican fishers are illegally catching anywhere
from 3 to 56 percent of the total U.S. Atlantic commercial shark quota,
and between 6 and 108 percent of the Gulf of Mexico regional commercial
quota, indicating a high degree of uncertainty in these estimates.
Updated data since 2005 show a decrease in the number of detected
incursions (Brewster-Geisz et al., 2010); however, the extent of IUU
fishing on the scalloped hammerhead sharks in the Gulf of Mexico
remains unknown. In 2012, Mexico established an annual shark fishing
prohibition in its jurisdictional Gulf of Mexico waters (from May 1 to
June 30) (DOF, 2012), which may also help deter future IUU fishing by
its fishers, at least during the prohibitive period.
Central & SW Atlantic DPS
In addition to its jurisdiction in NW Atlantic & GOM DPS waters,
the United States also has jurisdiction over a very small portion of
this DPS range, specifically the U.S. EEZ around Puerto Rico and the
U.S. Virgin Islands (as defined in 50 CFR 622.2), where Federal fishing
laws apply. NMFS recently published an amendment to the Consolidated
HMS FMP which specifically addresses Atlantic HMS fishery management
measures in the U.S. Caribbean territories (77 FR 59842; Oct. 1, 2012).
Due to substantial differences between some segments of the U.S.
Caribbean HMS fisheries and the HMS fisheries that occur off the
mainland of the United States (including permit possession, vessel
size, availability of processing and cold storage facilities, trip
lengths, profit margins, and local consumption of catches), NMFS
implemented measures to better manage the traditional small-scale
commercial HMS fishing fleet in the U.S. Caribbean Region. Among other
things, this rule created an HMS Commercial Caribbean Small Boat (CCSB)
permit, which: allows fishing for and sales of big eye, albacore,
yellowfin, and skipjack tunas, Atlantic swordfish, and Atlantic sharks
within local U.S. Caribbean market; collects HMS landings data through
existing territorial government programs; authorizes specific gears; is
restricted to vessels less than or equal to 45 feet (13.7 m) length
overall all; and may not be held in combination with any other Atlantic
HMS vessel permits. However, at this time, fishers who hold the CCSB
permit are prohibited from retaining Atlantic sharks, and are
restricted to fishing with only rod and reel, handline, and bandit gear
under the permit. Both the CCSB and Atlantic HMS regulations will help
protect scalloped hammerhead sharks, but only within the U.S. EEZ
around Puerto Rico and the U.S. Virgin Islands and from fishers under
U.S. jurisdiction.
Many other foreign commercial and artisanal fisheries operate
within the range of this DPS, with little to no regulatory oversight,
and thus existing regulations are likely inadequate to reduce the most
significant threats to the scalloped hammerhead shark population. For
example, artisanal gillnet fisheries, known for their substantial
bycatch problems, are still active in Central America, with many
allowed to operate in inshore nursery areas. Due in large part to the
number of sovereign states found in this region, the management of
shark species in Central America and the Caribbean remains largely
disjointed, with some countries lacking basic fisheries regulations
(Kyne et al., 2012). Other countries lack the capabilities to enforce
what has already been implemented. The Organization of the Fisheries
and Aquaculture Section of the Central American Isthmus (OSPECA) was
formed to address this situation by assisting with the development and
coordination of fishery management measures in Central America. OSPECA
recently approved a common regional finning regulation for eight member
countries from the Central American Integration System (SICA) (Belize,
Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras,
Nicaragua, and Panama). The regulation specifically requires sharks to
be landed with fins still attached for vessels fishing in SICA
countries or in international waters flying a SICA country flag. If
fins are to be traded in a SICA country, they must be accompanied by a
document from the country of origin certifying that they are not the
product of finning (Kyne et al., 2012). Other Central American and
Caribbean country-specific regulations include the banning or
restriction of longlines in certain fishing areas (Bahamas, Belize,
Panama), seasonal closures (Guatemala), shark fin bans (Colombia,
Mexico, Venezuela) and the prohibition of shark fishing (Bahamas and
Honduras). Unfortunately, enforcement of these regulations is weak,
with many reports of illegal and unregulated fishing activities. For
example, in May 2012, the Honduran navy seized hundreds of shark fins
from fishers operating illegally within the borders of its shark
sanctuary. As Kyne et al. (2012) reports, it is basically common
practice to move shark fins across borders for sale in countries where
enforcement is essentially lacking in this region.
In South America, Brazil has also banned finning, but continues to
find evidence of IUU fishing in its waters. In Bel[eacute]m in May
2012, the Brazilian Institute of Environmental and Renewable Natural
Resources (IBAMA) seized around 7.7 mt of illegally obtained dried
shark fins intended for export to China (Nickel, 2012). A few months
later, IBAMA confiscated more than 5 mt of illegal shark fins in Rio
Grande do Norte (Rocha de Medeiros, 2012), suggesting current
regulations and enforcement are not adequate to deter or prevent
illegal shark finning. In fact, it is estimated that illegal fishing
constitutes 32 percent of the Southwest Atlantic region's catch (based
on estimates of illegal and unreported catch
[[Page 20739]]
averaged over the years of 2000 to 2003; Agnew et al., 2009).
In addition, heavy industrial fishing off the coast of Brazil, with
the use of drift gillnets and longlines, remains largely unregulated,
as does the intensive artisanal fishery which accounts for about 50
percent of the fishing sector. Brazil currently has regulations
limiting the extension of pelagic gillnets and prohibiting trawls in
waters less than 3 nautical miles (5.6 km) from the coast; however, as
is the case with many regulations affecting this DPS, inadequate
enforcement of these laws has led to continued fishing in these inshore
nursery areas and resultant observed declines in both adult and
juvenile scalloped hammerhead abundance (Amorim et al., 1998; Kotas,
2008; CITES, 2010). Brazil is also presently working on implementing
new regulations to enforce recent ICCAT recommendations (Hazin personal
communication, 2012). ICCAT is the RFMO responsible for the
conservation of tunas and tuna-like species in the Atlantic Ocean and
its adjacent seas, and, as mentioned previously, adopted Recommendation
10-08 prohibiting the retention of hammerheads caught in association
with ICCAT-managed fisheries. Each Contracting Party to ICCAT is
responsible for implementing this recommendation. Many countries within
the Central & SW Atlantic DPS range are Contracting Parties to ICCAT,
including Brazil, Venezuela, Panama, Honduras, Nicaragua, Belize,
Trinidad & Tobago, Barbados, and St Vincent & the Grenadines. ICCAT
Recommendation 10-08 includes a special exception for developing
coastal States, allowing them to retain hammerhead sharks for local
consumption provided that they report their catch data to ICCAT,
endeavor not to increase catches of hammerhead sharks, and take the
necessary measures to ensure that no hammerhead parts enter
international trade. As this exception allows hammerheads to be
retained under certain circumstances, it may provide a lesser degree of
protection for hammerhead sharks in the developing coastal States that
choose to take advantage of the exception.
Given the information above, the ERA team ranked both IUU fishing
and the inadequacy of current regulatory mechanisms as moderate risks.
We agree that these factors, in combination with others (such as
overutilization and low species productivity), likely contribute
significantly to the Central & SW Atlantic DPS risk of extinction.
Eastern Atlantic DPS
The ICCAT convention area also covers the range of the Eastern
Atlantic DPS, providing some protection for scalloped hammerheads;
however, again, given the special exception available to developing
coastal States for local consumption, Recommendation 10-08 provides a
lesser degree of protection for hammerhead sharks in those fisheries.
Given this exception, the management measures that may be implemented
to achieve the ICCAT recommendation may not be adequate to protect the
shark from overutilization. Within the range of this DPS, many of the
countries that would qualify under this exemption, mainly those
countries along the west coast of Africa, also have weak or poorly
enforced country-specific shark fisheries regulations. In other words,
these countries will be able to continue fishing for scalloped
hammerhead sharks with little to no regulation on the harvest of the
species and existing regulatory mechanisms in these areas are not
considered adequate to control or reduce the primary threats to this
DPS.
In Europe, the European Parliament recently passed a proposal
prohibiting the removal of shark fins by all vessels in EU waters and
by all EU-registered vessels operating anywhere in the world.
Previously, the EU prohibited shark finning, but allowed fins and
bodies to be landed in different ports, resulting in enforcement
difficulties, and allowed justified exceptions and special permits for
finning, essentially diminishing the effectiveness of the finning ban.
In 2009, the EU accounted for up to 17 percent of the global shark
catch, and is the largest exporter of shark products to markets in
mainland China and Hong Kong. Therefore, in an effort to close the
loopholes in the original shark fin regulations and discourage the
wasteful practice of finning, the European Parliament passed the
proposal requiring fins be attached to landed sharks. This proposal is
expected to be approved by member states, which will make the draft law
definitive.
Many individual European countries have already implemented
measures to stop the practice of finning and conserve shark
populations. For example, England and Wales banned finning in 2009 and
no longer issue special permits for finning exceptions. France
prohibits on-board processing of sharks, and Spain recently passed a
regulation in 2011 that prohibits the capture, injury, trade, import
and export of scalloped hammerhead sharks, with a periodic evaluation
of their conservation status. Given that Spain is Europe's top shark
fishing nation, accounting for 7.3 percent of the global shark catch,
and was the world's largest exporter of shark fins to Hong Kong in
2008, this new regulation should provide significant protection for
scalloped hammerhead sharks from Spanish fishing vessels.
Although regulations in Europe appear to be moving towards the
sustainable use and conservation of shark species, these strict and
enforceable regulations do not extend farther south in the Eastern
Atlantic, where the majority of scalloped hammerhead sharks are caught.
Some western African countries have attempted to impose restrictions on
shark fishing; however, these regulations either have exceptions,
loopholes, or poor enforcement. For example, Mauritania has created a
6,000 km\2\ coastal sanctuary for sharks and rays, prohibiting targeted
shark fishing in this region; however, sharks, such as the scalloped
hammerhead, may be caught as bycatch in nets. Many other countries,
such as Namibia, Guinea, Cape-Verde, Sierra Leone, and Gambia, have
shark finning bans, but even with this regulation, scalloped hammerhead
sharks are may be caught with little to no restrictions on harvest
numbers. According to Diop and Dossa (2011), fishing in the SRFC region
now occurs year-round, including during shark breeding season, and, as
such, both pregnant and juvenile shark species may be fished, with
shark fins from fetuses included on balance sheets at landing areas.
Many of these state-level management measures also lack standardization
at the regional level (Diop and Dossa, 2011), which weakens some of
their effectiveness. For example, Sierra Leone and Guinea both require
shark fishing licenses; however, these licenses are much cheaper in
Sierra Leone, and as a result, fishers from Guinea fish for sharks in
Sierra Leone (Diop and Dossa, 2011). Also, although many of these
countries have recently adopted FAO recommended National Plans of
Action--Sharks, their shark fishery management plans are still in the
early implementation phase, and with few resources for monitoring and
managing shark fisheries, the benefits to sharks from these regulatory
mechanisms (such as reducing the threat of overutilization) have yet to
be realized (Diop and Dossa, 2011).
In addition, reports of IUU fishing are prevalent in the waters off
West Africa and account for around 37 percent of the region's catch,
the highest regional estimate of illegal fishing worldwide (Agnew et
al., 2009; EJF, 2012). From
[[Page 20740]]
January 2010 to July 2012, the UK-based non-governmental organization
Environmental Justice Foundation (EJF) conducted a surveillance project
in southern Sierra Leone to determine the extent of IUU fishing in
waters off West Africa (EJF, 2012). The EJF staff received 252 reports
of illegal fishing by industrial vessels in inshore areas, 90 percent
of which were bottom trawlers, with many vessels exporting their
catches to Europe and East Asia (EJF, 2012). The EJF (2012)
surveillance also found these pirate industrial fishing vessels
operating inside exclusion zones, using prohibited fishing gear,
refusing to stop for patrols, attacking local fishers and destroying
their gear, and fleeing to neighboring countries to avoid sanctions.
Due to a lack of resources, many West African countries are unable to
provide effective or, for that matter, any enforcement, with some
countries even lacking basic monitoring systems. These deficiencies
further increase the countries' susceptibility to IUU fishing,
resulting in heavy unregulated fishing pressure and likely
overexploitation of their fisheries.
Overall, the ERA team ranked the inadequacy of existing regulatory
measures and IUU fishing as moderate risks to the entire Eastern
Atlantic DPS. However, since this DPS is most abundant off waters of
West Africa, we conclude that the threats concentrated in this area
would not be greatly minimized by increased conservation measures
within European waters. The available data suggest that illegal fishing
is a serious and rampant problem in West African waters, and with lack
of enforcement of existing regulations and weak management of the
fisheries in this area, as evidenced by the observed substantial and
largely unregulated catches of both adult and juvenile hammerheads by
artisanal fishers in this region, we agree with ERA team's findings and
conclude that the combination of both the inadequacy of existing
regulatory measures and IUU fishing are contributing significantly to
the risk of extinction of this DPS. The ERA team concluded that the
threat of IUU fishing is also projected to increase as current
regulatory mechanisms are expected to remain the same in the
foreseeable future. We agree that the threat of IUU fishing is likely
to increase in the next 50 years without effective fishery management
regulations and enforcement in this DPS range.
Indo-West Pacific DPS
Multiple RFMOs cover the Indo-West Pacific DPS area, including the
Indian Ocean Tuna Commission in the Indian Ocean and the WCPFC in the
western Pacific. Currently, these RFMOs require the full utilization of
any retained catches of sharks, with a regulation that onboard fins
cannot weigh more than 5 percent of the weight of the sharks. These
regulations are aimed at curbing the practice of shark finning, but do
not prohibit the fishing of sharks. In addition, these regulations may
not even be effective in stopping finning of scalloped hammerheads, as
a recent study found the scalloped hammerhead shark to have an average
wet-fin-to-round-mass ratio of only 2.13 percent (n=81; Biery and
Pauly, 2012). This ratio suggests that fishing vessels operating in
these RFMO convention areas would be able to land more scalloped
hammerhead shark fins than bodies and still pass inspection. There are
no scalloped hammerhead-specific RFMO management measures in place for
this region, even though this DPS is heavily fished. Subsequently, this
species has seen population declines off the coasts of South Africa and
Australia, so much so that in 2012, New South Wales listed it as an
endangered species.
Few countries within the Indian Ocean have regulations aimed at
controlling the exploitation of shark species. Off northern Madagascar,
where there is an active artisanal fin fishery, sharks are an open
access resource, with no restrictions on gear, established quotas, or
fishing area closures (Robinson and Sauer, 2011). On the other hand,
Oman, Seychelles, Australia, South Africa, and Taiwan all have measures
to prevent the waste of shark parts and discourage finning. The
Maldives have even designated their waters as a shark sanctuary.
However, many of the top shark fishing nations and world's exporters of
fins are located within the range of this DPS, and have little to no
regulation (or enforcement) of their shark fisheries. For example,
Indonesia, which is the top shark fishing nation in the world, does not
currently have restrictions pertaining to shark fishing or finning.
Indonesian small-scale fisheries, which account for around 90 percent
of the total fisheries production, are not required to have fishing
permits (Varkey et al., 2010), nor are their vessels likely to have
insulated fish holds or refrigeration units (Tull, 2009), increasing
the incentive for shark finning by this sector (Lack and Sant, 2012).
Ultimately, their fishing activities remain largely unreported (Varkey
et al., 2010), which suggests that the estimates of Indonesian shark
catches are greatly underestimated. In fact, in Raja Ampat, an
archipelago in Eastern Indonesia, Varkey et al. (2010) estimated that
44 percent of the total shark catch in 2006 was unreported (including
small-scale and commercial fisheries unreported catch and IUU fishing).
Although Indonesia adopted an FAO recommended shark conservation
plan (National Plan of Action--Shark) in 2010, due to budget
constraints, it can only focus its implementation of key conservation
actions in one area, East Lombok (Satria et al. 2011). The current
Indonesian regulations that pertain to sharks are limited to those
needed to conform to international agreements (such as trade controls
for certain species listed by CITES (e.g. whale shark) or prescribed by
RFMOs) (Fischer et al., 2012). Due to this historical and current
absence of shark management measures, especially in the small-scale
fisheries sector, many of the larger shark species in Indonesian waters
have already been severely overfished. In the late 1990s, Indonesian
fishers noticed this decline in shark species and began moving south
from the South China Sea and Gulf of Thailand to the waters of northern
Australia in order to hunt for shark fins (Field et al., 2009). After
2001, Australian Customs patrol reported a large increase in the number
of IUU vessel sightings, mainly from Indonesia, with a peak occurring
in late 2005 and early 2006 (Field et al., 2009). During 2006, more
than 4,000 small traditional vessels were spotted by aerial surveys,
with an average of 22 IUU vessels fishing per day (Field et al., 2009).
Since this peak, there has been a decline in IUU fishing in Australian
waters, thought to be due to exhaustion of stocks in easily accessible
regions near the Australian EEZ, as well as international government
agreements and domestic policies (Field et al., 2009). Between July
2008 and June 2012, only 60 Indonesian vessels targeting sharks were
apprehended (Lack and Sant, 2012). Because illegal shark fishing is
often unreported, there is a lack of information available on the
species composition of the IUU shark catch. However, using a small
collection of shark fins that were confiscated from IUU fishers in
northern Australian waters, the Commonwealth Scientific and Industrial
Research Organisation identified that 8.8 percent of the illegal fins
belonged to S. lewini. Only one other shark species, the whitecheek
shark (Carcharhinus dussumieri), was a source of more fins (27.9
percent) (Lack and Sant, 2008).
In addition to within the Australian EEZ, IUU fishing, especially
for shark fins, has been reported in other waters throughout this DPS
range. The following are documented cases of IUU fishing as compiled by
Paul (2009). In 2008, off the coast of Africa, a
[[Page 20741]]
Namibian-flagged fishing vessel was found fishing illegally in
Mozambican waters, with 43 mt of sharks and 4 mt of shark fins onboard.
In 2009, a Taiwanese-flagged fishing trawler was found operating
illegally in the South Africa EEZ with 1.6 mt of shark fins onboard
without the corresponding carcasses. Also in 2009, 250 trawlers were
found to be poaching sharks in coastal areas in the Bay of Bengal with
the purpose of smuggling the sharks to Myanmar and Bangkok by sea.
There are also reports of traders exploiting shark populations in the
Arabian Gulf due to the lack of United Arab Emirates enforcement of
finning regulations. In the Western Pacific, in 2007, a Taiwanese-
flagged tuna boat was seized in Palau for IUU fishing and had 94 shark
bodies and 650 fins onboard. In 2008, a Chinese-flagged fishing vessel
was arrested by the Federated States of Micronesia (FSM) National
Police for fishing within the FSM's EEZ. Based on the number of fins
found onboard, there should have been a corresponding 9,000 bodies;
however, only 1,776 finned shark bodies were counted.
In Somalia, it is estimated that around 700 foreign-owned vessels
are operating in Somali waters without proper licenses, and
participating in unregulated fishing for highly-valued species like
sharks, tunas, and lobsters (HSTF, 2006). A study that provided
regional estimates of illegal fishing (using FAO fishing areas as
regions) found the Western Central Pacific (Area 71) and Eastern Indian
Ocean (Area 57) regions to have relatively high levels of illegal
fishing (compared to the rest of the regions), with illegal and
unreported catch constituting 34 and 32 percent of the region's catch,
respectively (Agnew et al., 2009).
Due to the historical exploitation of shark stocks, current levels
of IUU fishing, and noticeable decline in shark stocks, many Pacific
Island countries have created shark sanctuaries in their respective
waters, including Tokelau, Palau, Marshall Islands, American Samoa,
Cook Islands, and French Polynesia; however, enforcement in these
waters has proven difficult. Due to the small size of these Pacific
Island countries, many simply lack the resources to effectively patrol
their expansive oceanic territory. For example, the country of Palau
has only one patrol boat to enforce fishing regulations in its 604,000
km\2\ of ocean waters (Turagabeci, 2012). Because of the relatively
weak enforcement and potential for large catches of sharks in protected
waters, IUU vessels are known to fish in these areas, as mentioned
above, and have been found removing thousands of pounds of shark
products from these waters (Paul, 2009; AFP, 2012; Turagabeci, 2012).
So although the creation of shark sanctuaries is on the rise,
especially in areas of known S. lewini nursery grounds and ``hot
spots'' in this DPS' range, the protections that they afford the Indo-
West Pacific DPS may be minimal if IUU fishing is not controlled. Thus,
the ERA team ranked the threat of IUU fishing as a high risk and the
inadequacy of current regulatory mechanisms as a moderate risk to the
extinction of the Indo-West Pacific DPS now. The ERA team predicted
that regulatory measures may increase in the foreseeable future,
especially in nations that currently lack fishing regulations, but that
the threat of IUU fishing of this DPS will remain the same. We agree
with the ERA team's findings. Although nations may implement new, or
further strengthen existing, fishery management measures that may help
protect this DPS from overutilization, without effective enforcement of
these regulations, the benefits of these measures may not be realized.
Central Pacific DPS
Significant fishery management measures in the Central Pacific help
to protect this DPS from overfishing. As there are no directed shark
fisheries on this DPS, the biggest threat to the scalloped hammerhead
sharks comes from the Hawaii-based pelagic longline fishery. This
fishery, the largest in the state, currently targets tunas and billfish
and is managed under the auspices of the WPFMC. Due to the mostly
unregulated historical take that occurred in this fishery, and the
demand to continue fishery operations, the WPFMC implemented strict
management controls for this fishery. Although scalloped hammerheads
are only caught as bycatch in this longline fishery, the measures that
regulate their operations have helped to protect this species from
population declines. Some of these regulations include mandatory
observers, designated longline buffer zones, areas of prohibited
fishing, and periodic closures and effort limits. Since 1995, an
observer program has been in place with targeted coverage of 25 percent
in the deep-set longline sector and 100 percent in the shallow-set
sector. This program has provided valuable information on the number of
scalloped hammerheads caught as bycatch in the fishery. Since many
protected species can also be found in this DPS' range, the regulations
aimed at minimizing interactions with these species also protects
scalloped hammerhead sharks. For example, the Northwestern Hawaiian
Island (NWHI) Protected Species Zone prohibits longline fishing within
a 50 nautical mile (92.6 km) radius from the centers of the
Northwestern Hawaiian Islands and atolls. Commercial fishing is also
prohibited within the boundaries of the Marine National Monuments.
Around the Main Hawaiian Islands, areas have been designated as closed
to longline fishing year-round or open only at certain times of the
year. These regulations are strongly enforced, with catch and bycatch
of species regularly monitored.
Additionally, several regulatory mechanisms ban the practice of
finning, which offer a level of protection to this DPS from
overutilization for the shark fin trade. The U.S. Shark Conservation
Act of 2010 requires that sharks lawfully harvested in Federal waters,
including those located in the range of this DPS, and be landed with
their fins naturally attached. In 2000, Hawaii made it unlawful to
harvest or land shark fins in the state or territorial waters of the
state. These regulatory measures have effectively reduced the harvest
of sharks from the DPS and export of shark fins from the region to Hong
Kong (Clarke et al., 2007). Additionally, in July 2010, the State of
Hawaii enacted additional legislation aimed at curbing shark finning
(State of Hawaii SB2169), which may further reduce this threat.
Overall, the strict management of the Hawaii-based pelagic longline
fisheries, the additional implemented measures aimed at minimizing
protected species interactions, and the current catch data from
observers and scientists suggest the regulations in place in this
region are adequate to protect the Central Pacific DPS from the threat
of extinction. Therefore, the ERA team ranked the threat of inadequate
current regulatory mechanisms as a low risk and felt it was unlikely to
contribute significantly to this DPS' risk of extinction.
Eastern Pacific DPS
Similar to the RFMO regulations found in the Indo-West Pacific DPS,
the RFMO that covers the Eastern Pacific DPS area, the Inter-American
Tropical Tuna Commission (IATTC), requires the full utilization of any
retained catches of sharks, with a regulation that onboard fins cannot
weigh more than 5 percent of the weight of the sharks. Again, these
regulations are aimed at curbing the practice of shark finning, but do
not prohibit the fishing of sharks, and, as mentioned previously, the
fin-to-carcass ratio of 5 percent may not even be effective in
protecting scalloped hammerhead sharks from being finned. Although
there are no scalloped
[[Page 20742]]
hammerhead-specific RFMO management measures in place for this DPS,
many of the measures implemented by the IATTC are aimed at protecting
non-target species caught by tuna purse-seine vessels. In addition, the
IATTC encourages the release of live sharks, especially juveniles that
are caught incidentally and are not used for food and/or subsistence in
fisheries for tunas and tuna-like species. The IATTC also monitors
fishing activities, recommending maximum catch limits for longline
vessels based on recent stock assessment data and issuing closures to
purse-seine vessels in the convention area. Since hammerheads are
frequently a bycatch species in purse-seine nets, these closures should
provide extra protection for the Eastern Pacific DPS.
In the west-coast based U.S. fisheries, hammerheads are rarely
caught. This is likely due to the fact that the core scalloped
hammerhead range is located to the south and west of the U.S. West
Coast EEZ (Compagno, 1984). Additionally, recent regulations that
prohibit shallow longline sets, restrict specific types of fishing
gear, and close various areas to fishing have also contributed to the
rare catch of hammerheads in the U.S. Pacific fisheries. In 2004, NMFS
issued a final rule that prohibited shallow longline sets on the high
seas in the Pacific Ocean by vessels managed under the FMP for U.S.
West Coast Fisheries for HMS. Vessels under this FMP, however, are
permitted to target tunas with deep-set longline gear in the high seas
zone outside the U.S. EEZ, but the number participating is small.
During the 2009/2010 fishing season, fewer than three vessels, with 100
percent observer coverage, participated in this deep-set pelagic
longline fishery (PFMC, 2011). The California/Oregon drift gillnet
fishery is another U.S. west-coast based fishery where hammerheads may
be caught as bycatch. In this fishery, target species are mainly
swordfish and common thresher sharks. The majority of fishing effort
takes place from August through January within the southern California
Bight, as this fishery is closed from August 15th to November 15th, in
an area of approximately 213,000 square miles (551,670 km\2\) off the
coasts of central California up to Central Oregon for the protection of
leatherback sea turtles. Additional closures of this fishery take place
from February 1st to April 30th within 25 nautical miles (46.3 km) of
the coast, and from May 1st to August 14th within 75 nautical miles
(138.9 km). Even during the peak fishing season, observer data indicate
that hammerheads are rarely caught in this fishery. From 1990-2012, a
total of 8,310 sets were observed with only 50 hammerhead sharks caught
over this time period. However, none of the hammerhead sharks were
identified as S. lewini (SWRO, 2012).
In addition, in January 2011, the U.S. Shark Conservation Act of
2010 was signed into law, effectively banning the practice of shark
finning within the U.S. EEZ or on the high seas by U.S. fishing
vessels. Previously, the U.S. Pacific fisheries lacked a fins-attached
policy, but with the passage of the U.S. Shark Conservation Act, all
sharks must be landed with fins naturally attached. Thus, the U.S.
regulatory measures aimed at managing the Pacific fisheries, including
the Pacific longline and gillnet fisheries, appear adequate to protect
this DPS from overutilization by the U.S. west-coast based fisheries.
Many of the Central American countries in the Eastern Pacific also
have regulatory mechanisms in place with regard to sharks; however,
some are stronger than others. For example, Colombia, Costa Rica, and
El Salvador prohibit shark finning. Panama requires industrial fishers
to land sharks with fins naturally attached but artisanal fishers may
separate the fins from the carcass, as long as they satisfy the 5
percent weight rule. These regulations may help to deter finning, but
they do not protect sharks from overfishing.
Although Ecuador has banned directed fishing for sharks in its
waters, sharks caught in ``continental'' (i.e., not Galapagos)
fisheries may be landed if bycaught. Panama still allows directed
artisanal gillnet fishing for juvenile and adult sharks, including S.
lewini (Arriatti, 2011), as does the Mexican State of Sinaloa, where
the most popular gear in the elasmobranch fishery are bottom set
gillnets and longlines (Bizzarro et al., 2009). Bottom fixed gillnets
are also allowed in the artisanal fishery around ``Tres Marias'' Island
and Isabel Island in the Central Mexican Pacific, with bycatch
dominated by juvenile S. lewini (Perez-Jimenez et al., 2005). Although
Mexico is working towards promoting a sustainable shark and ray
fishery, the current legislation (NOM-029-PESCA-2006) allows artisanal
fishers to target hammerheads with longlines within 10 nm from the
shore and reduces the competition with larger commercial longline
vessels, which are subsequently restricted to waters 20 nm or more from
the shore. The restriction of these larger commercial longline vessels
will be beneficial to the artisanal fleet. However, given the artisanal
fleets' already substantial fishing effort on sharks (artisanal vessels
contribute 40 percent of the marine domestic production and comprise up
to 80 percent of the elasmobranch fishing effort; Cartamil et al.,
2011), this increase in fishing opportunity may further threaten the
Eastern Pacific DPS, especially since 62 percent of the total Mexican
domestic shark production comes from the Pacific Ocean (NOM-029-PESCA-
2006). In addition, many of the new regulations are not well understood
by current Mexican fishers, with very few fishers found to be in
compliance with them (Cartamil et al., 2011). Mexico also recently
prohibited shark fishing in its Pacific Ocean waters; however, the
prohibition period only lasts 3 months (from May 1 to July 31) (DOF,
2012).
More restrictive regulations, such as complete moratoriums on shark
fishing, can be found in this DPS range around Honduras and in the
Eastern Tropical Pacific Seascape. The Eastern Tropical Pacific
Seascape, a two million square kilometer region that encompasses the
national waters, coasts, and islands of Colombia, Costa Rica, Ecuador,
and Panama, was created to support marine conservation and sustainable
use of resources. The Seascape includes the Galapagos, Cocos, and
Malpelo Islands, and, although designated as a shark sanctuary, there
is evidence of illegal fishing by both local fishers and industrial
longliners within many of these marine protected areas. For example, in
Cocos Island National Park, off Costa Rica, a ``no take'' zone was
established in 1992, yet populations of S. lewini continued to decline
by an estimated 71 percent from 1992 to 2004 (Myers et al., n.d.). From
1998-2004, Jacquet et al. (2008) found Ecuadorian shark fin exports
exceeded mainland catches by 44 percent (average of 3,850 mt per year),
and suggested that this discrepancy may have been a result of illegal
fishing on protected Galapagos sharks. In 2004, this concern over
illegal fishing around the Galapagos Islands prompted a ban on the
exportation of fins, but only resulted in the establishment of new
illegal trade routes and continued exploitation of the scalloped
hammerhead shark (CITES, 2010). In 2007, Paul (2009) reports of a sting
operation by the Ecuadorian Environmental Police and the Sea Shepherd
Conservation Society which resulted in the seizure of 19,018 shark fins
that were being smuggled over the border on buses from Ecuador to Peru.
The fins were believed to come from protected sharks in the Galapagos
Islands. More recently, in November 2011, Colombian environmental
[[Page 20743]]
authorities reported a large shark massacre in the Malpelo wildlife
sanctuary. The divers counted 10 illegal Costa Rican trawler boats in
the wildlife sanctuary and estimated that as many as 2,000 sharks may
have been killed for their fins (Brodzinsky, 2011).
Although shark finning is discouraged in the waters of this DPS,
the ERA team voiced concerns about the allowed use of fishing gear that
is especially effective at catching schools of scalloped hammerhead
sharks within inshore and nursery areas in this DPS range. Thus, the
ERA team ranked the threat of inadequate current regulatory mechanisms
as a moderate risk. Additionally, without stronger enforcement,
especially in the marine protected areas in the Eastern Tropical
Pacific, the inadequacy of existing regulatory mechanisms will continue
to enable the IUU fishing, which was ranked as a threat contributing
significantly to this DPS' risk of extinction now and projected to
increase in the foreseeable future. We agree with the ERA team's
findings.
Other Natural or Man-Made Factors Affecting Its Continued Existence
Many sharks are thought to be biologically vulnerable to
overexploitation based on their life history parameters. As mentioned
previously, the scalloped hammerhead shark is no exception, with
relatively low estimated productivity values (r = 0.028-0.121; Miller
et al., 2013). Contributing to the scalloped hammerhead's biological
vulnerability is the fact that these sharks are obligate ram
ventilators (they must keep moving to ensure a constant supply of
oxygenated water) and suffer very high at-vessel fishing mortality in
bottom longline fisheries (Morgan and Burgess, 2007; Macbeth et al.,
2009). From 1994-2005, NMFS observers calculated that out of 455
scalloped hammerheads caught on commercial bottom longline vessels in
the northwest Atlantic and Gulf of Mexico, 91.4 percent were dead when
brought aboard (Morgan and Burgess, 2007). Size did not seem to be a
factor influencing susceptibility, as 70 percent of the young S. lewini
(0-65 cm), 95.2 percent of the juveniles (66-137 cm), and 90.9 percent
of the adults (>137 cm) suffered at-vessel fishing mortality. Soak time
of the longline had a positive effect on the likelihood of death
(Morgan and Burgess, 2007), with soak times longer than 4 hours
resulting in > 65 percent mortality (Morgan et al., 2009). When soak
time was shortened to 1hour, S. lewini at-vessel fishing mortality
decreased to 12 percent (Lotti, 2011). Lotti (2011) also found that at-
vessel fishing mortality was negatively correlated with S. lewini
length (p = 0.0032) and dissolved oxygen (p = 0.003), with male
scalloped hammerheads showing a higher probability of suffering from
at-vessel mortality compared to females (p = 0.0265).
Sphyrna spp. also suffer high mortality in beach net programs (Reid
and Krogh, 1992; Dudley and Simpfendorfer, 2006). In a study examining
the protective shark mesh program in New South Wales, Australia,
Sphyrna spp. was the taxonomic group with the lowest net survival
rates. The nets used in the protective mesh program were 150 m long and
6 m deep, with a mesh size of 50-60 cm and soak time generally between
12 and 48 hours. Out of the 2,031 hammerheads caught by this program
(from 1972-1990), only 1.7 percent were alive when cleared from the
nets (Reid and Krogh, 1992). Thus, due to the scalloped hammerhead's
high at-vessel fishing mortality on a variety of fishing gear, and the
difficulty of implementing or enforcing measures to mitigate this
mortality, the ERA team ranked this biological vulnerability as
contributing significantly to the risk of extinction of each of the
scalloped hammerhead shark DPSs. We agree that the species' high at-
vessel mortality may be a significant threat to the species, but only
in combination with other factors, such as low abundance, heavy fishing
pressure, or inadequate regulatory mechanisms that do not take into
account this biological vulnerability in the development of fishery
management measures. Therefore, we conclude that the scalloped
hammerhead's high at-vessel fishing mortality contributes a greater
risk of extinction that may be cause for concern to those DPSs where
abundance is low and decreasing and overutilization and/or regulatory
mechanisms are significant threats (i.e., Central & SW Atlantic DPS,
Eastern Atlantic DPS, Indo-West Pacific DPS, and Eastern Pacific DPS).
Another threat the ERA team identified as affecting the continued
existence of S. lewini is the shark's schooling behavior. This
schooling behavior increases the shark's likelihood of being caught in
large numbers. For example, fishers in Costa Rica were documented using
gillnets in shallow waters to target schools of juveniles and neonates
in these nursery areas (Zanella et al., 2009). In Brazil, schools of
neonates and juveniles are caught in large numbers by coastal gillnets
and recreational fishers in inshore waters, and subsequently their
abundance has significantly decreased over time (CITES, 2010). Off
South Africa, Dudley and Simpfendorfer (2006) reported significant
catches of newborn S. lewini by prawn trawlers, with estimates of 3,288
sharks in 1989, and 1,742 sharks in 1992. This schooling behavior also
makes the species a popular target for illegal fishing activity, with
fishers looking to catch large numbers of scalloped hammerhead sharks
(both adult and juveniles) quickly and with relatively little effort.
In the Malpelo wildlife sanctuary, divers had reported sightings of
schools of more than 200 hammerhead sharks before the sanctuary became
a recent target of IUU fishing vessels (Brodzinsky, 2011). Because this
schooling behavior provides greater access to large numbers of
scalloped hammerheads, the likelihood of this species being overfished
greatly increases. Thus, the ERA team ranked the schooling behavior as
a moderate risk for most of the DPSs, a factor that, in combination
with others, such as IUU fishing, contributes significantly to the DPS'
risk of extinction. In the Eastern Pacific DPS, the ERA team ranked
this schooling behavior as a high risk based on reports of frequent IUU
fishing on scalloped hammerhead schools in protected waters and the
evidence of heavy inshore fishing pressure on schools of juveniles and
neonates in nursery grounds. We agree with the ERA team's findings.
Overall Risk Summary
NW Atlantic & GOM DPS
The ERA team concluded, and we agree, that the NW Atlantic & GOM
DPS is at a ``low'' risk of extinction throughout all of its range, now
and in the foreseeable future. Although the ERA team had some concerns
about the significant decline in absolute abundance from fisheries,
they concluded that the population has a high likelihood of rebuilding
because of stronger fishery management measures and is unlikely to be
at risk of extinction due to trends in abundance, productivity, spatial
structure or diversity now or in the foreseeable future. Likelihood
points attributed to the current level of extinction risk categories
are as follows: No or Very Low Risk (6/50), Low Risk (20/50), Moderate
Risk (17/50), High Risk (7/50). None of the team members placed a
likelihood point in the ``Very high risk'' category for the overall
level of extinction risk now or in the foreseeable future, indicating
their strong certainty that the DPS is not, nor will it be, at a very
high risk of extinction. Likelihood
[[Page 20744]]
points attributed to the other categories for the level of extinction
risk in the foreseeable future are as follows: No or Very Low Risk (11/
50), Low Risk (26/50), Moderate Risk (12/50), High Risk (1/50). Based
on the likelihood point distributions, the team was fairly certain that
the DPS currently has a low to moderate risk of extinction. However,
the difference of only three likelihood points separating these two
risk categories indicates a level of uncertainty as to the severity of
the current threats and demographic risks. This level of uncertainty
diminishes in the foreseeable future, with the increased number and
majority of likelihood points for the low risk category.
Central & SW Atlantic DPS
The ERA team concluded, and we agree, that the Central & SW
Atlantic DPS is at a ``moderate'' risk of extinction throughout all of
its range, now and in the foreseeable future. The ERA team agreed that
the DPS is on a trajectory approaching a level of abundance and
productivity that places its current and future persistence in
question. Given the combination of threats including the inadequacy of
current regulatory mechanisms, the reports of heavy fishing, the high
at-vessel mortality rate, and the projected increase of commercial,
artisanal, and IUU fishing, the team does not envision a reversal of
demographic trends in the foreseeable future that would lessen its risk
of extinction. Likelihood points attributed to the categories for the
current level of extinction risk are as follows: Low Risk (8/50),
Moderate Risk (25/50), High Risk (14/50), and Very High Risk (3/50).
None of the team members placed a likelihood point in the ``No or very
low risk'' category for the overall level of extinction risk now or in
the foreseeable future, indicating their strong certainty that the DPS
is, and will continue to be, at some risk of extinction. Likelihood
points attributed to the other categories for the level of extinction
risk in the foreseeable future are as follows: Low Risk (8/50),
Moderate Risk (20/50), High Risk (15/50), and Very High Risk (7/50).
Based on the likelihood point distributions, the team was fairly
certain that the DPS has a moderate risk of extinction now, receiving
half of the votes, but expressed some uncertainty regarding the future
level of extinction risk, increasing the number of likelihood points in
the high and very high risk categories.
Eastern Atlantic DPS
The ERA team concluded, and we agree, that the Eastern Atlantic DPS
is at a ``high'' risk of extinction throughout all of its range, now
and in the foreseeable future. The ERA team had serious concerns
regarding the level of overutilization and lack of regulatory
mechanisms in the Eastern Atlantic DPS. Although Spain and other EU
countries have implemented new regulations aimed at protecting this
species in the Atlantic, these management measures are lacking in the
West African region where enforcement of existing measures is weak and
IUU fishing is rampant. There is no evidence of this situation in
western Africa changing in the foreseeable future, as resources are
very limited. Thus, the ERA team concluded that overutilization by
artisanal, industrial, and IUU fishing in this area is creating a DPS
that is at or near a level of abundance and productivity that places
its current and future persistence in question throughout its entire
range. Likelihood points attributed to the categories for the current
level of extinction risk are as follows: No or Very Low Risk (1/50),
Low Risk (6/50), Moderate Risk (14/50), High Risk (18/50), and Very
High Risk (11/50). Likelihood points attributed to the other categories
for the level of extinction risk in the foreseeable future are as
follows: Low Risk (7/50), Moderate Risk (14/50), High Risk (20/50), and
Very High Risk (9/50). None of the team members placed a likelihood
point in the ``No or very low risk'' category for the overall level of
extinction risk in the foreseeable future, indicating their strong
certainty that the DPS will be at some risk of extinction. Based on the
likelihood point distributions, the team was less certain about the
current risk of extinction for this DPS, with the moderate risk
category separated from the high risk category by only four likelihood
points. However, in the foreseeable future, the team expressed
increased certainty that the DPS would be at a high risk of extinction
with more likelihood points added to this category while the moderate
risk category remained the same.
Indo-West Pacific DPS
The ERA team concluded, and we agree, that the Indo-West Pacific
DPS is at a ``moderate'' risk of extinction throughout all of its
range, now and in the foreseeable future. The ERA team was mainly
concerned about the level of overutilization and limited regulatory
mechanisms in the Indo-West Pacific DPS and concluded that the DPS is
exhibiting a trajectory indicating that it is approaching a level of
abundance and productivity that places its current and future
persistence in question throughout its entire range. Given the
inadequacy of current regulatory mechanisms, the reports of heavy
fishing, increased industrialization, high at-vessel mortality rate,
and the projected increase of commercial, artisanal, and IUU fishing,
the team does not envision a reversal of demographic trends in the
foreseeable future that would reduce its risk of extinction throughout
all or a significant portion of its range. Likelihood points attributed
to the categories for the current level of extinction risk are as
follows: Low Risk (4/50), Moderate Risk (20/50), High Risk (17/50), and
Very High Risk (9/50). None of the team members placed a likelihood
point in the ``No or very low risk'' category for the overall level of
extinction risk now or in the foreseeable future, indicating their
strong certainty that the DPS is, and will continue to be, at some risk
of extinction. Likelihood points attributed to the other categories for
the level of extinction risk in the foreseeable future are as follows:
Low Risk (3/50), Moderate Risk (19/50), High Risk (16/50), and Very
High Risk (12/50). Based on the likelihood point distributions, the
team was fairly certain that the DPS has a moderate to high risk of
extinction. However, the difference of only three likelihood points
separating these two risk categories indicates a level of uncertainty
as to the severity of the current and future threats and demographic
risks. In addition, three likelihood points were moved to the very high
risk category in the foreseeable future. The team thought the DPS was
at a moderate risk of extinction, but were concerned that the situation
could actually be worse in the future.
Central Pacific DPS
The ERA team concluded, and we agree, that the Central Pacific DPS
is at a ``no or very low'' risk of extinction throughout all of its
range, now and in the foreseeable future. Although the ERA team had
concerns regarding the threat of overutilization by commercial
fisheries in combination with the scalloped hammerhead's tendency to
school, they felt that the current abundance and productivity of this
DPS, along with the number of suitable nursery grounds and effective
management measures, provided ample protection from extinction for this
DPS. Likelihood points attributed to the categories for the current
level of extinction risk are as follows: No or Very Low Risk (24/50),
Low Risk (19/50), and Moderate Risk (7/50). None of the team members
placed a likelihood point in the ``High risk'' or ``Very High
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Risk'' categories for the overall level of extinction risk now or in
the foreseeable future, indicating their strong certainty that the DPS
is not, nor will it be, at a high risk of extinction. Likelihood points
attributed to the other categories for the level of extinction risk in
the foreseeable future are as follows: No or Very Low Risk (27/50), Low
Risk (17/50), and Moderate Risk (6/50). Based on the likelihood point
distributions, the team was fairly certain that this DPS is at a no or
very low risk of extinction now and in the foreseeable future.
Eastern Pacific DPS
The ERA team concluded, and we agree, that the Eastern Pacific DPS
is at a ``high'' risk of extinction throughout all of its range, now
and in the foreseeable future. The ERA team had strong concerns
regarding the level of overutilization and limited regulatory
mechanisms or enforcement of fishery regulations in the Eastern
Pacific, and concluded that the DPS is at or near a level of abundance
and productivity that places its current and future persistence in
question throughout its entire range. Likewise, the present threats,
which include heavy fishing, IUU fishing, and overutilization by
industrial/commercial and artisanal fisheries, coupled with the
behavioral and biological aspects that increase S. lewini's
susceptibility and mortality to certain fishing gear, will only serve
to exacerbate the demographic risks currently faced by the DPS in the
foreseeable future. Likelihood points attributed to the current level
of extinction risk categories are as follows: Low Risk (6/50), Moderate
Risk (17/50), High Risk (21/50), and Very High Risk (5/50). None of the
team members placed a likelihood point in the ``No or very low risk''
category for the overall level of extinction risk now or in the
foreseeable future, indicating their strong certainty that the DPS is,
and will continue to be, at some risk of extinction. Likelihood points
attributed to the other categories for the level of extinction risk in
the foreseeable future are as follows: Low Risk (4/50), Moderate Risk
(15/50), High Risk (21/50), and Very High Risk (10/50). Based on the
likelihood point distributions, the team was fairly certain that the
DPS has a moderate to high risk of extinction, with the high risk
category receiving more of the votes. In addition, five likelihood
points were moved to the very high risk category in the foreseeable
future, indicating increased concern for this DPS.
Efforts Being Made to Protect Scalloped Hammerhead Sharks
Section 4(b)(1)(A) of the ESA requires the Secretary of Commerce to
take into account ``* * * efforts, if any, being made by any State or
foreign nation, or any political subdivision of a State or foreign
nation, to protect such species, whether by predator control,
protection of habitat and food supply, or other conservation practices,
within any area under its jurisdiction or on the high seas.'' The ESA
therefore directs us to consider all conservation efforts being made to
conserve the species. The joint USFWS and NOAA Policy on Evaluation of
Conservation Efforts When Making Listing Decisions (``PECE Policy'', 68
FR 15100; March 28, 2003) further identifies criteria we use to
determine whether formalized conservation efforts that have yet to be
implemented or to show effectiveness contribute to making listing
unnecessary, or to list a species as threatened rather than endangered.
In determining whether a formalized conservation effort contributes to
a basis for not listing a species, or for listing a species as
threatened rather than endangered, we must evaluate whether the
conservation effort improves the status of the species under the ESA.
Two factors are key in that evaluation: (1) For those efforts yet to be
implemented, the certainty that the conservation effort will be
implemented and (2) for those efforts that have not yet demonstrated
effectiveness, the certainty that the conservation effort will be
effective. The following is a review of the major conservation efforts
and an evaluation of whether these efforts are reducing or eliminating
threats by having a positive conservation benefit and thus improving
the status of the scalloped hammerhead shark DPSs.
U.S. Fishery Management: Amendment 5 to the Consolidated HMS FMP
On April 28, 2011, NMFS determined that the Northwest Atlantic and
Gulf of Mexico scalloped hammerhead shark stock was overfished and
experiencing overfishing (76 FR 23794; April 28, 2011). Under National
Standard (NS) 1 of the MSA and implementing regulations (50 CFR
600.310), NMFS is required to ``prevent overfishing while achieving, on
a continuing basis, the OY [optimum yield] from each fishery for the
U.S. fishing industry.'' In order to accomplish this, NMFS must
determine the MSY and specify status determination criteria to allow a
determination of the status of the stock. In cases where NMFS has
determined that a fishery is overfished, the MSA, Section 304, mandates
that NMFS notify the appropriate Fishery Management Council and request
that the Council take action. The Council must then take action within
2 years to end overfishing and rebuild the stock in the shortest time
possible. The NMFS Atlantic HMS Management Division is responsible for
managing scalloped hammerhead sharks, and is thus responsible for
taking appropriate action to end overfishing and rebuild the fishery.
Given this statutory mandate, there is a certainty that NMFS will
implement conservation and management measures by 2013 that will
provide for the rebuilding of the scalloped hammerhead shark stock.
NMFS is currently in the process of finalizing Amendment 5 to the
Consolidated HMS FMP (proposed on November 26, 2012, 77 FR 70552;
public comment period closed February 12, 2013), which will prescribe
management measures and implementing regulations to conserve the
scalloped hammerhead shark NW Atlantic & GOM DPS.
The second criterion of the PECE policy is the evaluation that the
conservation effort will be effective. The specific conservation effort
that is trying to be achieved is the rebuilding of the Northwest
Atlantic and Gulf of Mexico scalloped hammerhead shark stock. The
conservation effort is achieved when the current biomass (B) levels of
the stock are equal to BMSY. BMSY is the level of
stock abundance at which harvesting the resource can be sustained on a
continual basis at the level necessary to support MSY. Stocks are
considered healthy when F (fishing caused mortality) is less than or
equal to 0.75 FMSY and B is greater than or equal to
BOY (BOY = approximately 1.25 to 1.30
BMSY; the biomass level necessary to produce OY on a
continuing basis). Specifically, NMFS will establish annual catch
limits and accountability measures for the scalloped hammerhead shark
stock to allow for rebuilding of the stock. With fishery rebuilding
plans, there is an explicit time frame for achieving this conservation
effort, which will be stated in the Amendment to the FMP. Usually,
rebuilding targets are set at 10 years unless the biology of the stock
of fish, other environmental conditions, or management measures under
an international agreement in which the United States participates,
dictate otherwise. Then the specified time period for rebuilding may be
adjusted upward by one mean generation time. The rebuilding plans are
based on quantifiable, scientifically valid parameters and the progress
of the
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stock is monitored and reported on as stock assessments are conducted.
Although Amendment 5 has not yet been finalized, examination of
previous rebuilding plans for Atlantic coastal shark species may
provide insight into the effectiveness of these regulatory measures.
Section 304(e)(7) of the Magnuson-Stevens Act requires that the
Secretary review rebuilding progress at routine intervals that may not
exceed 2 years, and thus every year NMFS tracks the biomass trends for
overfished stocks to monitor this rebuilding progress. Overall, the
total number of stocks that have been rebuilt under a rebuilding plan
since 2001 is 26 (approximately 11 percent of the total number of
managed stocks, and 34 percent of the stocks that have/had rebuilding
plans). Of the 21 stocks managed by the 2006 Consolidated HMS FMP,
around half are currently under a rebuilding plan. Two HMS stocks have
rebuilt since being under a rebuilding plan: Atlantic swordfish, which
was rebuilt in year 9 of a 10-year plan, and the Atlantic blacktip
shark, which is thought to have been rebuilt in year 5 of a 39-year
plan (however, this stock may have never been overfished).
The status of the sandbar shark stock may provide a better
comparison to the potential success rate of the scalloped hammerhead
shark rebuilding plan. The sandbar shark used to be managed as part of
the LCS complex; however, enough data were available to conduct a
separate stock assessment of the species. In 2006, the results of the
sandbar shark stock assessment showed that the stock was overfished
with overfishing occurring. Using the available scientific information,
NMFS published Amendment 2 to the 2006 Consolidated HMS FMP,
establishing the rebuilding plan for the sandbar shark. Management
measures in the implementing regulations included separating the
sandbar shark from the LCS complex and setting specific quotas and
retention limits for the species that would allow it to rebuild.
Specifically, NMFS allowed sandbar retention only by vessels with shark
research permits, and the limits depended upon research objectives. The
success of this rebuilding plan can be seen in the latest SouthEast
Data, Assessment, and Review (SEDAR 21) of the sandbar shark stock
(finalized in 2011), which determined that the sandbar shark stock was
still overfished but no longer experiencing overfishing. In addition,
it was also determined that the current total allowable catch (TAC) for
the fishery could result in a greater than 70 percent probability of
rebuilding by the current rebuilding date of 2070. Similar to the
sandbar shark, NMFS is working to develop a rebuilding plan that will
set specific quota and retention limits for scalloped hammerhead sharks
and allow for the recovery of these sharks in the Northwest Atlantic
and Gulf of Mexico. Based on the criteria in the PECE policy, in our
judgment the Amendment 5 to the Consolidated HMS FMP is a conservation
effort with high certainty of implementation and is highly likely to be
sufficiently effective to substantially reduce the overutilization of
the NW Atlantic & GOM scalloped hammerhead shark DPS. Overutilization
of this DPS by commercial and recreational fisheries was identified as
a primary threat presenting a moderate risk of extinction to the DPS
currently, but was expected to decrease in risk severity in the
foreseeable future. We anticipate that the foregoing conservation
measures will benefit the status of the species in the foreseeable
future, thereby further decreasing its extinction risk from the threat
of overutilization identified by the ERA team.
Shark Fin Bans
The concern regarding the practice of finning and its effect on
global shark populations has been growing both domestically and
internationally. In the United States, California, Oregon, Washington,
and Hawaii have already passed legislation banning the sale,
possession, and distribution of shark fins. The support for this
legislation from the public, as well as conservation groups, has
prompted many other states to follow suit, with proposals for similar
bills. Likewise, in Canada, Bill C-380 was introduced in December of
2011, and would prohibit the import or attempt to import shark fins
that are not attached to the rest of the shark carcass into Canada.
The push to stop shark finning and curb the trade of shark fins is
also evident overseas and most surprisingly in Asian countries, where
the demand for shark fin soup is highest. Taiwan, the third top
exporter of shark fins to Hong Kong in 2008, banned the practice of
shark finning at sea in 2012. Likewise, many hotels in Taiwan, such as
the W Taipei, the Westin Taipei, and the Silks Palace at National
Palace Museum, also vowed to stop serving shark fin dishes as part of
their menus. In November of 2011, the Chinese restaurant chain South
Beauty removed shark fin soup from its menus, and in 2012, the luxury
Shangri-La Hotel chain joined this effort, banning shark fin from its
72 hotels, most of which are found in Asia. Effective January 1, 2012,
the Peninsula Hotel chain stopped serving shark fin and related
products. This ban covers the Chinese restaurant and banqueting
facilities at The Peninsula hotels in Hong Kong, Shanghai, Beijing,
Tokyo, Bangkok, and Chicago. Many supermarket chains in Asia also vowed
to halt the sale of shark fin products. In 2011, ColdStorage, a chain
with several outlets in Singapore, banned the sale of shark fin from
its stores, and in 2012, the Singapore supermarket chains FairPrice and
Carrefour stated they would also stop selling shark fin in outlets in
the city-state. Many of these bans have just recently been implemented,
and thus their effect on reducing the threat of S. lewini
overutilization is unknown.
While there seems to be a growing trend to prohibit and discourage
shark finning domestically and internationally, it is difficult to
predict at this time whether the trend will be effective in reducing
the threat of IUU fishing to any particular DPS. We do not find these
to be conservation measures that we consider effective in reducing
current threats to the any of the DPSs as we evaluate whether listing
is warranted.
Convention on International Trade in Endangered Species of Wild Fauna
and Flora
CITES is an international agreement between governments that
regulates international trade in wild animals and plants. It encourages
a proactive approach and the species covered by CITES are listed in
appendices according to the degree of endangerment and the level of
protection provided. Appendix I includes species threatened with
extinction; trade in specimens of these species is permitted only in
exceptional circumstances. Appendix II includes species not necessarily
threatened with extinction, but for which trade must be controlled to
avoid exploitation rates incompatible with species survival. Appendix
III contains species that are protected in at least one country, which
has asked other CITES Parties for assistance in controlling the trade.
In 2012, S. lewini was submitted for inclusion on CITES Appendix
III by Costa Rica, and is now effectively listed in the appendix. An
Appendix III listing allows international trade of the species, but
provides a means of gathering trade data and other relevant
information. For example, the export of S. lewini specimens from Costa
Rica requires a CITES export permit issued by the Costa Rica CITES
Management Authority. For the export of S. lewini specimens from any
other country, a CITES certificate of
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origin by the Management Authority of that country is required. This
conservation effort will allow Costa Rica to gain better international
cooperation in controlling trade of S. lewini both into and out of the
country. This type of tracking information will also provide previously
unavailable data on the origin of S. lewini specimens, including fins,
currently being traded in the global market and allow for a better
determination of the degree of exploitation and use of this species by
domestic and foreign fishing fleets. Although this CITES listing will
likely provide us with better data in the future to assess the status
of DPSs, it is not a conservation measure that we consider effective in
reducing current threats to the any of the DPSs as we evaluate whether
listing is warranted.
Other Conservation Efforts
There are many other smaller national and international
organizations with shark-focused goals that include advocating the
conservation of sharks through education and campaign programs and
conducting shark research to fill data gaps regarding the status of
shark species. These organizations include: the Pew Environment Group,
Oceana, Ocean Conservancy, Shark Trust, Bite-Back, Shark Project,
Pelagic Shark Research Foundation, Shark Research Institute, and Shark
Savers. More information on the specifics of these programs and groups
can be found on their Web sites. All of these conservation efforts and
non-regulatory mechanisms are beneficial to the persistence of the
scalloped hammerhead shark. The implementation of many of these
efforts, especially the shark research programs as well as the CITES
Appendix III listing, will help to fill current data gaps in S. lewini
abundance and utilization records. However, it is too soon to tell
whether the collective conservation efforts of non-governmental
organizations targeting finning practices and promoting public
awareness of declines in shark populations will be effective in
reducing the threats, particularly those related to overutilization of
the scalloped hammerhead DPSs. Much of the data on shark catches and
exports since implementation of these conservation efforts is not yet
available.
Proposed Determinations
Section 4(b)(1) of the ESA requires that NMFS make listing
determinations based solely on the best scientific and commercial data
available after conducting a review of the status of the species and
taking into account those efforts, if any, being made by any state or
foreign nation, or political subdivisions thereof, to protect and
conserve the species. We have reviewed the best available scientific
and commercial information including the petition, the status review
report (Miller et al., 2013), and other published and unpublished
information, and we have consulted with species experts and individuals
familiar with scalloped hammerhead sharks.
For the reasons stated above, and as summarized below, we conclude
that: (1) Scalloped hammerhead sharks in the NW Atlantic & GOM, Central
& SW Atlantic, Eastern Atlantic, Indo-West Pacific, Central Pacific,
and Eastern Pacific meet the discreteness and significance criteria for
DPSs; (2) the Eastern Atlantic and Eastern Pacific scalloped hammerhead
shark DPSs are in danger of extinction throughout their ranges; (3) the
Central & SW Atlantic and Indo-West Pacific scalloped hammerhead shark
DPSs are likely to become endangered throughout their ranges in the
foreseeable future; and (4) the NW Atlantic & GOM and Central Pacific
scalloped hammerhead shark DPs are not in danger of extinction or
likely to become so throughout all of their ranges in the foreseeable
future.
Scalloped hammerhead sharks occurring in the NW Atlantic & GOM are
discrete and significant from other members of their species based on
the following: (1) Genetic differences between this population and
those scalloped hammerhead sharks inhabiting waters of the Pacific,
Indian, and eastern Atlantic oceans; (2) tagging studies that show
limited distance movements, with no tagged sharks observed in Central
America or Brazil, supporting the conclusion that the NW Atlantic & GOM
population is isolated from other populations; (3) significant U.S.
fishery management measures for this population that separate it from
scalloped hammerheads found in the Central & SW Atlantic (with the
exception of those in the U.S. EEZ Caribbean), with differences in
control of S. lewini exploitation and regulatory mechanisms of
significance across these international boundaries; and (4) evidence
that a loss of this segment would result in a significant gap in the
range of the taxon (from New Jersey to Florida and throughout the GOM),
with tagging and genetic studies that suggest the segment would
unlikely be rapidly repopulated through immigration.
Scalloped hammerhead sharks occurring in the Central & SW Atlantic
are discrete and significant from other members of their species based
on the following: (1) Genetic differences between this population and
those scalloped hammerhead sharks inhabiting waters of the Pacific,
Indian, and eastern Atlantic oceans; (2) tagging studies that suggest
limited distance migrations along coastlines, continental margins, and
submarine features with no observed mixing between the Central & SW
Atlantic population and the NW Atlantic & GOM population, supporting
the conclusion of isolation from other populations; (3) fishery
management measures that are lacking in this DPS compared to NW
Atlantic & GOM DPS (with the exception of U.S. EEZ Caribbean), with
differences in control S. lewini exploitation and regulatory mechanisms
of significance across these international boundaries; and (4) evidence
that a loss of this segment would result in a significant gap in the
range of the taxon (from Caribbean to Uruguay), with oceanographic
conditions that would act as barriers to re-colonization, and tagging
and genetic studies that suggest the segment would unlikely be rapidly
repopulated through immigration.
Scalloped hammerhead sharks occurring in the Eastern Atlantic are
discrete and significant from other members of their species based on
the following: (1) Genetic differences between this population and
those scalloped hammerhead sharks inhabiting waters of the Pacific,
Indian, and western Atlantic oceans; (2) tagging studies that suggest
limited distance migrations along coastlines, continental margins, and
submarine features, with genetic studies that show migration around the
southern tip of Africa is rare (i.e., no mixing with those sharks found
in the Indian Ocean), supporting the conclusion of isolation from other
populations; and (4) evidence that loss of this segment would result in
a significant gap in the range of the taxon (from Mediterranean Sea to
Namibia), with oceanographic conditions that would act as barriers to
re-colonization, and tagging and genetic studies that suggest the
segment would unlikely be rapidly repopulated through immigration.
Scalloped hammerhead sharks occurring in the Indo-West Pacific are
discrete from other members of their species based on the following:
(1) Genetic differences between this population and those scalloped
hammerhead sharks inhabiting waters of the Eastern Pacific and Atlantic
oceans; (2) tagging and genetic studies that show limited distance
migrations and support isolation from other populations, but suggest
males mix readily along coastlines and continental margins in this DPS
due to the high connectivity of
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habitat; (3) fishery management measures that are lacking in this DPS
compared to those found in the Central Pacific DPS range, with
differences in control of S. lewini exploitation and regulatory
mechanisms of significance across international boundaries; and (4)
evidence that loss of this segment would result in a significant gap in
the range of the taxon (from South Africa to Japan and south to
Australia and New Caledonia and neighboring Island countries), with
oceanographic conditions that would act as barriers to re-colonization,
and tagging and genetic studies that suggest the segment would unlikely
be rapidly repopulated through immigration.
Scalloped hammerhead sharks occurring in the Central Pacific are
discrete from other members of their species based on the following:
(1) Genetic differences between this population and those scalloped
hammerhead sharks inhabiting waters of the Eastern Pacific and Atlantic
oceans; (2) tagging studies that show limited distance migrations, with
adults remaining ``coastal'' within the archipelago, and separated from
other populations by bathymetric barriers, supporting the conclusion of
isolation from other populations; (3) significant U.S. fishery
management measures for this DPS that separate it from the Indo-West
Pacific DPS, with differences in control of S. lewini exploitation and
regulatory mechanisms of significance across international boundaries;
and (4) evidence that loss of this segment would result in a
significant gap in the range of the taxon (from Kure Atoll to Johnston
Atoll, including the Hawaiian Archipelago) and valuable and productive
nursery grounds, with oceanographic conditions that would act as
barriers to re-colonization, and tagging and genetic studies that
suggest this segment would unlikely be rapidly repopulated through
immigration.
Scalloped hammerhead sharks occurring in the Eastern Pacific are
discrete from other members of their species based on the following:
(1) Genetic differences between this population and those scalloped
hammerhead sharks inhabiting waters of the Indo-West Pacific, Central
Pacific, and Atlantic oceans; (2) tagging studies that suggest wide
movements around island and occasional long-distance dispersals between
neighboring islands with similar oceanographic conditions, but
isolation from other DPSs by bathymetric barriers and oceanographic
conditions, supporting the conclusion of isolation from other
populations; and (4) evidence that loss of this segment would result in
a significant gap in the range of the taxon (from southern CA, USA to
Peru), with oceanographic conditions that would act as barriers to re-
colonization, and tagging and genetic studies that suggest the segment
would unlikely be rapidly repopulated through immigration.
The ESA does not define the terms ``significant portion of its
range'' (SPOIR) or ``foreseeable future.'' With regard to SPOIR, we
(NMFS and U.S. Fish and Wildlife Service, or, the Services) have
proposed a ``Draft Policy on Interpretation of the Phrase `Significant
Portion of Its Range' in the Endangered Species Act's Definitions of
`Endangered Species' and `Threatened Species''' (76 FR 76987; December
9, 2011), which is consistent with our past practice as well as our
understanding of the statutory framework and language. While the Draft
Policy remains in draft form, the Services are to consider the
interpretations and principles contained in the Draft Policy as non-
binding guidance in making individual listing determinations, while
taking into account the unique circumstances of the species under
consideration.
The Draft Policy provides that: (1) If a species is found to be
endangered or threatened in only a significant portion of its range,
the entire species is listed as endangered or threatened, respectively,
and the Act's protections apply across the species' entire range; (2) a
portion of the range of a species is ``significant'' if its
contribution to the viability of the species is so important that,
without that portion, the species would be in danger of extinction; (3)
the range of a species is considered to be the general geographical
area within which that species can be found at the time FWS or NMFS
makes any particular status determination; and (4) if the species is
not endangered or threatened throughout all of its range, but it is
endangered or threatened within a significant portion of its range, and
the population in that significant portion is a valid DPS, we will list
the DPS rather than the entire taxonomic species or subspecies.
Given that the scalloped hammerhead shark is a highly mobile
species, with very few restrictions governing its movements within each
DPS, we did not find any evidence to suggest that a portion of any
single DPS' range had increased importance over another with respect to
the species' survival within each respective DPS. The ERA team
initially considered the islands in the Central Pacific as a potential
SPOIR, given their numerous nursery grounds and likelihood as a
population source for the region. However, upon further review, the ERA
team found that this area qualified as a DPS and analyzed it as such.
In addition, the available data did not indicate any portion of any DPS
range as being more significant than another. Potentially important
aspects of a DPS range, such as identified nursery grounds or ``hot
spots'' of aggregations, were represented elsewhere in the range,
suggesting that if the population in a specific nursery ground or ``hot
spot'' disappeared, the DPS would not be in danger of extinction
throughout its range. There was no evidence of any DPS being limited to
a specific nursery ground or schooling location. In fact, Duncan et al.
(2006) provided mtDNA data that argued against strong natal homing
behavior by the species, and instead suggested that the habitat
characteristics of the nursery area were more important than the
location. Since available nursery habitat was not identified as a
limiting factor in any of the DPSs, we did not consider this as a
significant portion of range. Thus, when making our determinations, we
considered the status of each DPS throughout its entire range as no
SPOIRs could be identified.
With respect to the term ``foreseeable future,'' we accepted the
ERA team's definition and rationale of 50 years as reasonable for the
reliable prediction of threats to the biological status of the species.
That rationale was provided in detail above.
As discussed, we have independently reviewed and evaluated the best
available scientific and commercial information related to the status
of each DPS, including the demographic risks and trends and the
multiple threats related to the factors set forth in the ESA Section
4(a)(1)(A)-(E). As we explained, no portion of any DPS's range is
considered significant and we therefore have determined that no DPS is
threatened or endangered in a significant portion of its range. Our
determinations set forth above and summarized below are thus based on
the status of each DPS across its entire range. Based on our evaluation
of the status of each DPS and the threats to its persistence we
predicted the likelihood that each DPS is in danger of extinction
throughout all of its range now and in the foreseeable future. We
considered each of the statutory factors to determine whether it
presented an extinction risk to each DPS on its own. We also considered
the combination of those factors to determine whether they collectively
contributed to the extinction of each DPS. As required by the ESA,
Section 4(b)(1)(a), we also took into account efforts to protect
scalloped hammerhead sharks by states, foreign nations and others and
evaluated
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whether those efforts provide a conservation benefit to each DPS and
reduced threats to the extent that a DPS did not warrant listing or
could be listed as threatened rather than endangered. Our conclusions
and proposed listing determinations are based on a synthesis and
integration of the foregoing information, factors and considerations.
Below are the summaries of our proposed determinations:
We have determined that the Eastern Atlantic DPS of scalloped
hammerhead sharks is currently in danger of extinction throughout all
of its range. Factors supporting this conclusion include
overutilization, inadequacy of existing regulatory mechanisms and other
natural or manmade factors, specifically: (1) Low productivity rates;
(2) high susceptibility to overfishing, especially given its schooling
behavior; (3) significant historical removals of sharks, including
scalloped hammerheads, by artisanal and industrial fisheries, with
directed shark fisheries still in operation and heavy fishing pressure
despite evidence of species' extirpations and declines of large
hammerheads; (4) high at-vessel mortality rate associated with
incidental capture in fisheries (resulting in further reduction of
population productivity and abundance); (5) popularity of the species
in the shark fin trade; and (6) inadequate regulatory mechanisms along
the coast of West Africa, with severe enforcement issues leading to
heavy IUU fishing. Therefore, we propose to list the Eastern Atlantic
DPS of scalloped hammerhead sharks as endangered.
We have determined that the Eastern Pacific DPS of scalloped
hammerhead sharks is also currently in danger of extinction throughout
all of its range. Factors supporting this conclusion include
overutilization, inadequacy of existing regulatory mechanisms and other
natural or manmade factors, specifically: (1) Reduced abundance,
declining population trends and catch, and evidence of size truncation;
(2) low productivity rates; (2) high susceptibility to overfishing,
especially given its schooling behavior, with artisanal fisheries
targeting juveniles of the species in inshore and nursery areas; (3)
high at-vessel mortality rate associated with incidental capture in
fisheries (resulting in further reduction of population productivity
and abundance); (4) popularity of the species in the shark fin trade
and importance in Mexican artisanal fisheries; and (5) limited
regulatory mechanisms and weak enforcement in many areas, leading to
IUU fishing of the species, especially in protected waters. Therefore,
we propose to list the Eastern Pacific DPS of scalloped hammerhead
sharks as endangered.
We have determined that the Central & SW Atlantic DPS of scalloped
hammerhead sharks is not presently in danger of extinction, but likely
to become so in the foreseeable future throughout all of its range.
Factors supporting a conclusion that this DPS is not presently in
danger of extinction include: (1) Low productivity rates but moderate
rebound potential to pelagic longline fisheries common in this DPS; (2)
ICCAT recommendations slated for implementation (or already
implemented) by Contracting Parties that offer protection for this
species from ICCAT fishing vessels; (3) regulations that limit the
extension of pelagic gillnets and trawls, shark fin bans, and
prohibitions on shark fishing or the retention of scalloped hammerhead
sharks; and (4) evidence that sharks are still present in significant
enough numbers to be caught by commercial and artisanal fisheries.
Factors supporting a conclusion that the DPS is likely to become in
danger of extinction in the foreseeable future include overutilization,
inadequacy of existing regulatory mechanisms and other natural or
manmade factors, specifically: (1) Decreasing catch trends suggesting
population decline, (2) high susceptibility to overfishing, especially
given its schooling behavior, with artisanal fisheries catching large
numbers of juveniles in inshore and nursery areas; (3) high at-vessel
mortality rate associated with incidental capture in fisheries
(resulting in further reduction of population productivity and
abundance); (4) popularity of the species in the shark fin trade; and
(5) limited regulatory mechanisms and/or weak enforcement in some
areas, leading to IUU fishing of the species. Therefore, we propose to
list the Central & SW Atlantic DPS of scalloped hammerhead sharks as
threatened.
We have determined that the Indo-West Pacific DPS of scalloped
hammerhead sharks is not presently in danger of extinction, but likely
to become so in the foreseeable future throughout all of its range.
Factors supporting a conclusion that this DPS is not presently in
danger of extinction include: (1) Relatively high reported catches of
the species off the coasts of South Africa and Queensland, Australia;
(2) still observed throughout the entire range of this DPS with the
overall population size uncertain given the expansive range of this
DPS; and (3) current regulations that prevent the waste of shark parts
and discourage finning in this region, with the number of shark
sanctuaries on the rise in the Western Pacific. Factors supporting a
conclusion that the DPS is likely to become in danger of extinction in
the foreseeable future include overutilization, inadequacy of existing
regulatory mechanisms and other natural or manmade factors,
specifically: (1) Decreases in CPUE of sharks off the coasts of South
Africa and Australia and in longline catch in Papua New Guinea and
Indonesian waters, suggesting localized population declines, (2) high
susceptibility to overfishing, especially given its schooling behavior,
in artisanal fisheries and industrial/commercial fisheries; (3) high
at-vessel mortality rate associated with incidental capture in
fisheries (resulting in further reduction of population productivity
and abundance); (4) popularity of the species in the shark fin trade;
and (5) inadequate regulatory mechanisms and/or weak enforcement of
current regulations in many areas, resulting in frequent reports of IUU
fishing of the species. Therefore, we propose to list the Indo-West
Pacific DPS of scalloped hammerhead sharks as threatened.
We conclude that the NW Atlantic & GOM DPS of scalloped hammerhead
sharks is not presently in danger of extinction, nor is it likely to
become so in the foreseeable future throughout all of its range.
Factors supporting this conclusion include: (1) Abundance numbers for
this DPS that are lower than historical levels but seem to have been
constant over the past few years, with a high probability of population
recovery under recent catch levels; (2) significant fishery management
measures that are in place, including both state and Federal
regulations, with scalloped hammerhead-specific sustainability,
conservation, and rebuilding goals; (3) extensive EFH for the species
that has been designated along the range of this DPS, with no evidence
of habitat loss or destruction; and (4) low productivity rates for the
species but moderate rebound potential to pelagic longline fisheries
within the range of this DPS. We determined that the comprehensive
science-based management of this DPS and enforceable and effective
regulatory structure as discussed previously in this proposed rule
significantly minimize this DPS' extinction risk from threats of
overutilization and IUU fishing to the point where we do not find this
DPS in danger of extinction now or in the foreseeable future. Under
current fishery management, the DPS has a high probability of
rebuilding within 50 years, and considering formalized
[[Page 20750]]
conservation efforts, such as Amendment 5 to the HMS FMP and
implementing regulations, we find that these regulatory mechanisms are
likely to further reduce the significant threats to this DPS (primarily
overexploitation by commercial and recreational fisheries, exacerbated
by the species' high at-vessel fishing mortality) and benefit the
conservation status of the DPS. Therefore, we conclude that listing the
NW Atlantic & GOM scalloped hammerhead shark DPS as threatened or
endangered under the ESA is not warranted at this time.
We also conclude that the Central Pacific DPS of scalloped
hammerhead sharks is not presently in danger of extinction, nor is it
likely to become so in the foreseeable future throughout all of its
range. Factors supporting this conclusion include: (1) Abundance
numbers for this DPS that are perceived to be high; (2) ample
productive nursery grounds that are present in the range of this DPS,
with no evidence of habitat loss or destruction; (3) low productivity
rates for the species but data that show it is rarely caught in
Hawaiian-based fisheries; and (4) significant fishery management
measures that are in place, including both state and Federal
regulations, that protect the species from extinction. We determined
that the high population abundance of this DPS and effective existing
fishery management measures and regulatory structure, reflected in the
rare catch of this DPS in fisheries operating within its range,
minimized the threat of overutilization by commercial fisheries to the
point where this DPS is not currently at risk of extinction. In
addition, we find that regulatory mechanisms will likely only increase
in their strength and effectiveness in minimizing the extinction risk
of this DPS in the next 50 years, making it unlikely that the threat of
overutilization will be a significant risk to this DPS' continued
existence in the foreseeable future. Therefore, we conclude that
listing the Central Pacific scalloped hammerhead shark DPS as
threatened or endangered under the ESA is not warranted at this time.
Effects of Listing
Conservation measures provided for species listed as endangered or
threatened under the ESA include recovery plans and actions (16 U.S.C.
1536(f)); concurrent designation of critical habitat if prudent and
determinable (16 U.S.C. 1533(a)(3)(A)); Federal agency requirements to
consult with NMFS and to ensure its actions do not jeopardize the
species or result in adverse modification or destruction of critical
habitat should it be designated (16 U.S.C. 1536); and prohibitions on
taking (16 U.S.C. 1538). Recognition of the species' plight through
listing promotes conservation actions by Federal and state agencies,
foreign entities, private groups, and individuals. Should the proposed
listings be made final, a recovery plan or plans may be developed,
unless such plan would not promote the conservation of the species.
Identifying Section 7 Consultation Requirements
Section 7(a)(2) (16 U.S.C. 1536(a)(2)) of the ESA and NMFS/FWS
regulations require Federal agencies to confer with us on actions
likely to jeopardize the continued existence of species proposed for
listing, or that result in the destruction or adverse modification of
proposed critical habitat. If a proposed species is ultimately listed,
Federal agencies must consult on any action they authorize, fund, or
carry out if those actions may affect the listed species or its
critical habitat and ensure that such actions do not jeopardize the
species or result in adverse modification or destruction of critical
habitat should it be designated. Examples of Federal actions that may
affect scalloped hammerhead shark DPSs include, but are not limited to:
alternative energy projects, discharge of pollution from point sources,
non-point source pollution, contaminated waste and plastic disposal,
dredging, pile-driving, water quality standards, vessel traffic,
aquaculture facilities, military activities, and fisheries management
practices.
Critical Habitat
Critical habitat is defined in section 3 of the ESA (16 U.S.C.
1532(3)) as: (1) The specific areas within the geographical area
occupied by a species, at the time it is listed in accordance with the
ESA, on which are found those physical or biological features (a)
essential to the conservation of the species and (b) that may require
special management considerations or protection; and (2) specific areas
outside the geographical area occupied by a species at the time it is
listed upon a determination that such areas are essential for the
conservation of the species. ``Conservation'' means the use of all
methods and procedures needed to bring the species to the point at
which listing under the ESA is no longer necessary. Section 4(a)(3)(a)
of the ESA (16 U.S.C. 1533(a)(3)(A)) requires that, to the extent
prudent and determinable, critical habitat be designated concurrently
with the listing of a species. Designations of critical habitat must be
based on the best scientific data available and must take into
consideration the economic, national security, and other relevant
impacts of specifying any particular area as critical habitat. If we
determine that it is prudent and determinable, we will publish a
proposed designation of critical habitat for scalloped hammerhead
sharks in a separate rule. Public input on features and areas that may
meet the definition of critical habitat for the Central & SW Atlantic,
Indo-West Pacific, and Eastern Pacific DPS is invited. These DPSs are
the only DPSs proposed for listing that occur in U.S. waters or its
territories.
Take Prohibitions
Because we are proposing to list the Eastern Pacific and Eastern
Atlantic DPSs as endangered, all of the take prohibitions of section
9(a)(1) of the ESA (16 U.S.C. 1538(a)(1)) will apply to those
particular species if they become listed as endangered. These include
prohibitions against importing, exporting, engaging in foreign or
interstate commerce, or ``taking'' of the species. ``Take'' is defined
under the ESA as ``to harass, harm, pursue, hunt, shoot, wound, kill,
trap, capture, or collect, or attempt to engage in any such conduct.''
These prohibitions apply to all persons, organizations and entities
subject to the jurisdiction of the United States, including in the
United States, its territorial sea, or on the high seas.
In the case of threatened species, ESA section 4(d) requires the
Secretary to issue regulations deemed necessary and appropriate for the
conservation of the species. We have flexibility under section 4(d) to
tailor protective regulations based on the needs of and threats to the
species. The section 4(d) protective regulations may prohibit, with
respect to threatened species, some or all of the acts which section
9(a) of the ESA prohibits with respect to endangered species. We will
evaluate protective regulations pursuant to section 4(d) for the
threatened scalloped hammerhead shark DPSs and propose any considered
necessary and advisable for conservation of these species in a future
rulemaking. In order to inform our consideration of appropriate
protective regulations for these DPSs, we seek information from the
public on the threats to the Central & SW Atlantic DPS and the Indo-
West Pacific DPS and possible measures for their conservation.
Identification of Those Activities That Would Constitute a Violation of
Section 9 of the ESA
On July 1, 1994, NMFS and FWS published a policy (59 FR 34272) that
[[Page 20751]]
requires us to identify, to the maximum extent practicable at the time
a species is listed, those activities that would or would not
constitute a violation of section 9 of the ESA. The intent of this
policy is to increase public awareness of the effect of a listing on
proposed and ongoing activities within a species' range. We will
identify, to the extent known at the time of the final rule, specific
activities that will not be considered likely to result in violation of
section 9, as well as activities that will be considered likely to
result in violation. Based on currently available information, we
conclude that the following types of activities are those that may be
most likely to violate the section 9 prohibitions against ``take'' of
the scalloped hammerhead shark Eastern Atlantic and Eastern Pacific
DPSs include, the following: (1) Importation of fins or any part of a
scalloped hammerhead shark; (2) exportation of fins or any part of a
scalloped hammerhead shark; (3) take of fins or any part of a scalloped
hammerhead shark, including fishing for, capturing, handling, or
possessing scalloped hammerhead sharks or fins; (4) sale of fins or any
part of a scalloped hammerhead shark; (5) delivery of fins or any part
of a scalloped hammerhead shark; and (6) any activities that may impact
the water column attributes in scalloped hammerhead nursery grounds
(e.g. development and habitat alterations, point and non-point source
discharge of persistent contaminants, toxic waste and other pollutant
disposal). We emphasize that whether a violation results from a
particular activity is entirely dependent upon the facts and
circumstances of each incident. The mere fact that an activity may fall
within one of these categories does not mean that the specific activity
will cause a violation; due to such factors as location and scope,
specific actions may not result in direct or indirect adverse effects
on the species. Further, an activity not listed may in fact result in a
violation.
Role of Peer Review
The intent of the peer review policy is to ensure that listings are
based on the best scientific and commercial data available. In December
2004, the Office of Management and Budget (OMB) issued a Final
Information Quality Bulletin for Peer Review establishing minimum peer
review standards, a transparent process for public disclosure of peer
review planning, and opportunities for public participation. The OMB
Bulletin, implemented under the Information Quality Act (Pub. L. 106-
554), is intended to enhance the quality and credibility of the Federal
government's scientific information, and applies to influential or
highly influential scientific information disseminated on or after June
16, 2005. To satisfy our requirements under the OMB Bulletin, we
obtained independent peer review of the status review report.
Independent specialists were selected from the academic and scientific
community for this review. All peer reviewer comments were addressed
prior to dissemination of the final status review report and
publication of this proposed rule.
On July 1, 1994, the NMFS and USFWS published a series of policies
regarding listings under the ESA, including a policy for peer review of
scientific data (59 FR 34270). The intent of the peer review policy is
to ensure that listings are based on the best scientific and commercial
data available. Prior to a final listing, NMFS will solicit the expert
opinions of three qualified specialists selected from the academic and
scientific community, Federal and state agencies, and the private
sector on listing recommendations to ensure the best biological and
commercial information is being used in the decision-making process, as
well as to ensure that reviews by recognized experts are incorporated
into the review process of rulemakings developed in accordance with the
requirements of the ESA.
Public Comments Solicited on Listing
To ensure that the final action resulting from this proposal will
be as accurate and effective as possible, we solicit comments and
suggestions from the public, other governmental agencies, the
scientific community, industry, environmental groups, and any other
interested parties. Comments are encouraged on this proposal (See DATES
and ADDRESSES). Specifically, we are interested in information
regarding: (1) The proposed scalloped hammerhead DPS delineations; (2)
the population structure of scalloped hammerhead sharks; (3) habitat
within the range of the proposed for listing DPSs that was present in
the past, but may have been lost over time; (4) biological or other
relevant data concerning any threats to the scalloped hammerhead shark
DPSs we propose for listing; (5) the range, distribution, and abundance
of these scalloped hammerhead shark DPSs; (6) current or planned
activities within the range of the scalloped hammerhead shark DPSs we
propose for listing and their possible impact on these DPSs; (7) recent
observations or sampling of the scalloped hammerhead shark DPSs we
propose for listing; and (8) efforts being made to protect the
scalloped hammerhead shark DPSs we propose to list. We are also
specifically interested in information regarding the Indo-West Pacific
DPS, mainly the population structure, range, distribution, and recent
observations or sampling of scalloped hammerhead sharks around the
Western Pacific Islands.
Public Comments Solicited on Critical Habitat
We request quantitative evaluations describing the quality and
extent of habitats for the Central & SW Atlantic, Eastern Pacific, and
Indo-West Pacific DPSs, as well as information on areas that may
qualify as critical habitat for these proposed DPSs. Specific areas
that include the physical and biological features essential to the
conservation of these DPSs, where such features may require special
management considerations or protection, should be identified.
Essential features may include, but are not limited to, features
specific to individual species' ranges, habitats and life history
characteristics within the following general categories of habitat
features: (1) Space for individual growth and for normal behavior; (2)
food, water, air, light, minerals, or other nutritional or
physiological requirements; (3) cover or shelter; (4) sites for
reproduction and development of offspring; and (5) habitats that are
protected from disturbance or are representative of the historical,
geographical, and ecological distributions of the species (50 CFR
424.12(b)). Areas outside the occupied geographical area should also be
identified, if such areas themselves are essential to the conservation
of the species. ESA implementing regulations at 50 CFR 424.12(h)
specify that critical habitat shall not be designated within foreign
countries or in other areas outside of U.S. jurisdiction. Therefore, we
request information only on potential areas of critical habitat within
waters under U.S. jurisdiction.
Section 4(b)(2) of the ESA requires the Secretary to consider the
``economic impact, impact on national security, and any other relevant
impact'' of designating a particular area as critical habitat. Section
4(b)(2) also authorizes the Secretary to exclude from a critical
habitat designation those particular areas where the Secretary finds
that the benefits of exclusion outweigh the benefits of designation,
unless excluding that area will result in extinction of the species.
For features and areas potentially qualifying as critical habitat, we
also request information describing: (1) Activities or other threats to
the essential features or
[[Page 20752]]
activities that could be affected by designating them as critical
habitat; and (2) the positive and negative economic, national security
and other relevant impacts, including benefits to the recovery of the
species, likely to result if these areas are designated as critical
habitat. We seek information regarding the conservation benefits of
designating areas within waters under U.S. jurisdiction as critical
habitat. In keeping with the guidance provided by OMB (2000; 2003), we
seek information that would allow the monetization of these effects to
the extent possible, as well as information on qualitative impacts to
economic values.
Data reviewed may include, but are not limited to: (1) Scientific
or commercial publications; (2) administrative reports, maps or other
graphic materials; (3) information received from experts; and (4)
comments from interested parties. Comments and data particularly are
sought concerning: (1) Maps and specific information describing the
amount, distribution, and use type (e.g., foraging or migration) by the
proposed scalloped hammerhead shark DPSs, as well as any additional
information on occupied and unoccupied habitat areas; (2) the reasons
why any habitat should or should not be determined to be critical
habitat as provided by sections 3(5)(A) and 4(b)(2) of the ESA; (3)
information regarding the benefits of designating particular areas as
critical habitat; (4) current or planned activities in the areas that
might be proposed for designation and their possible impacts; (5) any
foreseeable economic or other potential impacts resulting from
designation, and in particular, any impacts on small entities; (6)
whether specific unoccupied areas may be essential to provide
additional habitat areas for the conservation of the proposed DPSs; and
(7) potential peer reviewers for a proposed critical habitat
designation, including persons with biological and economic expertise
relevant to the species, region, and designation of critical habitat.
We seek information regarding critical habitat for the proposed
scalloped hammerhead shark DPSs as soon as possible, but no later than
July 5, 2013.
Public Hearings
If requested by the public by May 20, 2013, hearings will be held
regarding the proposed scalloped hammerhead shark DPSs. If hearings are
requested, details regarding location(s), date(s), and time(s) will be
published in a forthcoming Federal Register notice.
References
A complete list of all references cited herein is available upon
request (see FOR FURTHER INFORMATION CONTACT).
Classification
National Environmental Policy Act
The 1982 amendments to the ESA, in section 4(b)(1)(A), restrict the
information that may be considered when assessing species for listing.
Based on this limitation of criteria for a listing decision and the
opinion in Pacific Legal Foundation v. Andrus, 657 F. 2d 829 (6th Cir.
1981), we have concluded that ESA listing actions are not subject to
the environmental assessment requirements of the National Environmental
Policy Act (See NOAA Administrative Order 216-6).
Executive Order 12866, Regulatory Flexibility Act, and Paperwork
Reduction Act
As noted in the Conference Report on the 1982 amendments to the
ESA, economic impacts cannot be considered when assessing the status of
a species. Therefore, the economic analysis requirements of the
Regulatory Flexibility Act are not applicable to the listing process.
In addition, this proposed rule is exempt from review under Executive
Order 12866. This proposed rule does not contain a collection-of-
information requirement for the purposes of the Paperwork Reduction
Act.
Executive Order 13132, Federalism
In accordance with E.O. 13132, we determined that this proposed
rule does not have significant Federalism effects and that a Federalism
assessment is not required. In keeping with the intent of the
Administration and Congress to provide continuing and meaningful
dialogue on issues of mutual state and Federal interest, this proposed
rule will be given to the relevant state agencies in each state in
which the species is believed to occur, and those states will be
invited to comment on this proposal. We have considered, among other
things, Federal, state, and local conservation measures. As we proceed,
we intend to continue engaging in informal and formal contacts with the
state, and other affected local or regional entities, giving careful
consideration to all written and oral comments received.
List of Subjects
50 CFR Part 223
Endangered and threatened species, Exports, Imports,
Transportation.
50 CFR Part 224
Endangered and threatened species, Exports, Imports,
Transportation.
Dated: March 28, 2013.
Alan D. Risenhoover,
Director, Office of Sustainable Fisheries, performing the functions and
duties of the Deputy Assistant Administrator for Regulatory Programs,
National Marine Fisheries Service.
For the reasons set out in the preamble, 50 CFR parts 223 and 224
are proposed to be amended as follows:
PART 223--THREATENED MARINE AND ANADROMOUS SPECIES
0
1. The authority citation for part 223 continues to read as follows:
Authority: 16 U.S.C. 1531-1543; subpart B, Sec. 223.201-202
also issued under 16 U.S.C. 1361 et seq.; 16 U.S.C. 5503(d) for
Sec. 223.206(d)(9).
0
2. In Sec. 223.102, paragraphs (c)(30) and (c)(31) are added to read
as follows:
Sec. 223.102 Enumeration of threatened marine and anadromous species.
* * * * *
[[Page 20753]]
----------------------------------------------------------------------------------------------------------------
Species \1\ Citation(s) for Citation(s) for
-------------------------------------------------- Where listed listing critical habitat
Common name Scientific name determination(s) designation(s)
----------------------------------------------------------------------------------------------------------------
* * * * * * *
(c) * * *
(30) Scalloped hammerhead Sphyrna lewini... Central and Southwest [INSERT FR
shark--Central & SW Atlantic Atlantic Distinct CITATION & DATE
DPS. Population Segment. WHEN PUBLISHED AS
The boundaries for A FINAL RULE].
this DPS are as
follows: bounded to
the north by 28[deg]
N. lat., to the east
by 30[deg] W. long.,
and to the south by
36[deg] S. lat.
Includes all waters
of the Caribbean Sea,
comprising the
Bahamas' EEZ off the
coast of Florida as
well as Cuba's EEZ.
(31) Scalloped hammerhead Sphyrna lewini... Indo-West Pacific [INSERT FR
shark--Indo-West Pacific DPS. Distinct Population CITATION & DATE
Segment. The WHEN PUBLISHED AS
boundaries for this A FINAL RULE].
DPS are as follows:
bounded to the south
by 36[deg] S. lat.,
to the west by
15[deg] E. long., and
to the north by
40[deg] N. lat. In
the east, the
boundary line extends
from175[deg] W. long.
due south to 10[deg]
N. lat., then due
east along 10[deg] N.
lat. to 140[deg] W.
long., then due south
to 4[deg] S. lat.,
then due east along
4[deg] S. lat. to
130[deg] W. long, and
then extends due
south along 130[deg]
W. long.
* * * * * * *
----------------------------------------------------------------------------------------------------------------
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement,
see 61 FR 4722, February 7, 1996), and evolutionarily significant units (ESUs) (for a policy statement, see 56
FR 58612, November 20, 1991).
* * * * *
PART 224--ENDANGERED MARINE AND ANADROMOUS SPECIES
0
3. The authority citation for part 224 continues to read as follows:
Authority: 16 U.S.C. 1531-1543 and 16 U.S.C. 1361 et seq.
0
4. Amend the table in Sec. 224.101 by adding an entry for Scalloped
hammerhead shark--Eastern Atlantic DPS, and by adding an entry for
Scalloped hammerhead shark--Eastern Pacific DPS at the end of the table
in Sec. 224.101(a) to read as follows:
Sec. 224.101 Enumeration of endangered marine and anadromous species
* * * * *
(a) * * *
----------------------------------------------------------------------------------------------------------------
Species \1\ Citation(s) for Citation(s) for
-------------------------------------------------- Where listed listing critical habitat
Common name Scientific name determination(s) designation(s)
----------------------------------------------------------------------------------------------------------------
* * * * * * *
Scalloped hammerhead shark-- Sphyrna lewini... Eastern Atlantic [INSERT FR NA.
Eastern Atlantic DPS. Distinct Population CITATION & DATE
Segment. The WHEN PUBLISHED AS
boundaries for this A FINAL RULE].
DPS are as follows:
Bounded to the west
by 30[deg] W. long.,
to the north by
40[deg] N. lat., to
the south by 36[deg]
S. lat., and to the
east by 20[deg] E.
long., but includes
all waters of the
Mediterranean Sea.
Scalloped hammerhead shark-- Sphyrna lewini... Eastern Pacific [INSERT FR NA.
Eastern Pacific DPS. Distinct Population CITATION & DATE
Segment. The WHEN PUBLISHED AS
boundaries for this A FINAL RULE].
DPS are as follows:
bounded to the north
by 40[deg] N lat. and
to the south by
36[deg] S lat. The
western boundary line
extends from140[deg]
W. long. due south to
10[deg] N., then due
west along 10[deg] N.
lat. to 140[deg] W.
long., then due south
to 4[deg] S. lat.,
then due east along
4[deg] S. lat. to
130[deg] W. long, and
then extends due
south along 130[deg]
W. long.
----------------------------------------------------------------------------------------------------------------
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement,
see 61 FR 4722, February 7, 1996), and evolutionarily significant units (ESUs) (for a policy statement, see 56
FR 58612, November 20, 1991).
* * * * *
[FR Doc. 2013-07781 Filed 4-4-13; 8:45 am]
BILLING CODE 3510-22-P