[Federal Register Volume 80, Number 154 (Tuesday, August 11, 2015)]
[Proposed Rules]
[Pages 48061-48069]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-19551]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Parts 223 and 224

[Docket No. 150506426-5426-01]
RIN 0648-XD942


Endangered and Threatened Wildlife; 90-day Finding on a Petition 
To List the Bigeye Thresher Shark as Threatened or Endangered Under the 
Endangered Species Act

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: 90-day petition finding, request for information, and 
initiation of status review.

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SUMMARY: We, NMFS, announce the 90-day finding on a petition to list 
the bigeye thresher shark (Alopias superciliosus) range-wide, or in the 
alternative, as one or more distinct population segments (DPSs) 
identified by the petitioners as endangered or threatened under the 
U.S. Endangered Species Act (ESA). We find that the petition presents 
substantial scientific or commercial information indicating that the 
petitioned action may be warranted for the species worldwide. 
Accordingly, we will initiate a status review of bigeye thresher shark 
range-wide at this time. To ensure that the status review is 
comprehensive, we are soliciting scientific and commercial information 
regarding this species.

DATES: Information and comments on the subject action must be received 
by October 13, 2015.

ADDRESSES: You may submit comments, information, or data, identified by 
``NOAA-NMFS-2015-0089'' by any one of the following methods:
     Electronic Submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal. Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2015-0089. Click the ``Comment Now'' icon, 
complete the required fields, and enter or attach your comments.
     Mail or hand-delivery: Office of Protected Resources, 
NMFS, 1315 East-West Highway, Silver Spring, MD 20910.
    Instructions: You must submit comments by one of the above methods 
to ensure that we receive, document, and consider them. 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. All 
comments received are a part of the public record and will generally be 
posted for public viewing on http://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. We 
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

FOR FURTHER INFORMATION CONTACT: Chelsey Young, NMFS, Office of 
Protected Resources (301) 427-8491.

SUPPLEMENTARY INFORMATION:

Background

    On April 27, 2015, we received a petition from Defenders of 
Wildlife requesting that we list the bigeye thresher shark (Alopias 
superciliosus) as endangered or threatened under the ESA, or, in the 
alternative, to list one or more distinct population segments (DPSs), 
should we find they exist, as threatened or endangered under the ESA. 
Defenders of Wildlife also requested that critical habitat be 
designated for this species in U.S. waters concurrent with final ESA 
listing. The petition states that the bigeye thresher shark merits 
listing as an endangered or threatened species under the ESA because of 
the following: (1) The species faces threats from historical and 
continued fishing for both commercial and recreational purposes; (2) 
life history characteristics and limited ability to recover from 
fishing pressure make the species particularly vulnerable to 
overexploitation; and (3) regulations are inadequate to protect the 
bigeye thresher shark.

ESA Statutory Provisions and Policy Considerations

    Section 4(b)(3)(A) of the ESA of 1973, as amended (U.S.C. 1531 et 
seq.), requires, to the maximum extent practicable, that within 90 days 
of receipt of a petition to list a species as threatened or endangered, 
the Secretary of Commerce make a finding on whether that petition 
presents substantial scientific or commercial information indicating 
that the petitioned action may be warranted, and promptly publish the 
finding in the Federal Register (16 U.S.C. 1533(b)(3)(A)). When we find 
that substantial scientific or commercial information in a petition and 
in our files indicates the petitioned action may be warranted (a 
``positive 90-day finding''), we are required to promptly commence a 
review of the status of the species concerned, which includes 
conducting a comprehensive review of the best available scientific and 
commercial information. Within 12 months of receiving the petition, we 
must conclude the review with a finding as to whether, in fact, the 
petitioned action is warranted. Because the finding at the 12-month 
stage is based on a significantly more thorough review of the available 
information, a ``may be warranted'' finding at the 90-day stage does 
not prejudge the outcome of the status review.
    Under the ESA, a listing determination may address a ``species,'' 
which is defined to also include subspecies and, for any vertebrate 
species, any DPS that interbreeds when mature (16 U.S.C. 1532(16)). A 
joint NMFS-U.S. Fish and Wildlife Service (USFWS) policy clarifies the 
agencies' interpretation of the phrase ``distinct population segment'' 
for the purposes of listing, delisting, and reclassifying a species 
under the ESA (``DPS Policy''; 61 FR 4722; February 7, 1996). A 
species, subspecies, or DPS is ``endangered'' if it is in danger of 
extinction throughout all or a significant portion of its range, and 
``threatened'' if it is likely to become endangered within the 
foreseeable future throughout all or a significant portion of its range 
(ESA sections 3(6) and 3(20), respectively; 16 U.S.C. 1532(6) and 
(20)). Pursuant to the ESA and our implementing regulations, the 
determination of whether a species is threatened or endangered shall be 
based on any one or a combination of the following five section 4(a)(1) 
factors: The present or threatened destruction, modification, or 
curtailment of habitat or range; overutilization for commercial, 
recreational, scientific, or educational purposes; disease or 
predation; inadequacy of existing regulatory mechanisms; and any other 
natural or manmade factors affecting the species' existence (16 U.S.C. 
1533(a)(1), 50 CFR 424.11(c)).
    ESA-implementing regulations issued jointly by NMFS and USFWS (50 
CFR 424.14(b)) define ``substantial information'' in the context of 
reviewing a petition to list, delist, or reclassify a species as the 
amount of information that would lead a reasonable person to

[[Page 48062]]

believe that the measure proposed in the petition may be warranted. 
When evaluating whether substantial information is contained in a 
petition, we must consider whether the petition: (1) Clearly indicates 
the administrative measure recommended and gives the scientific and any 
common name of the species involved; (2) contains detailed narrative 
justification for the recommended measure, describing, based on 
available information, past and present numbers and distribution of the 
species involved and any threats faced by the species; (3) provides 
information regarding the status of the species over all or a 
significant portion of its range; and (4) is accompanied by the 
appropriate supporting documentation in the form of bibliographic 
references, reprints of pertinent publications, copies of reports or 
letters from authorities, and maps (50 CFR 424.14(b)(2)).
    At the 90-day stage, we evaluate the petitioner's request based 
upon the information in the petition, including its references, and the 
information readily available in our files. We do not conduct 
additional research, and we do not solicit information from parties 
outside the agency to help us in evaluating the petition. We will 
accept the petitioner's sources and characterizations of the 
information presented, if they appear to be based on accepted 
scientific principles, unless we have specific information in our files 
that indicates the petition's information is incorrect, unreliable, 
obsolete, or otherwise irrelevant to the requested action. Information 
that is susceptible to more than one interpretation or that is 
contradicted by other available information will not be dismissed at 
the 90-day finding stage, so long as it is reliable and a reasonable 
person would conclude that it supports the petitioner's assertions. 
Conclusive information indicating the species may meet the ESA's 
requirements for listing is not required to make a positive 90-day 
finding. We will not conclude that a lack of specific information alone 
negates a positive 90-day finding, if a reasonable person would 
conclude that the unknown information itself suggests an extinction 
risk of concern for the species at issue.
    To make a 90-day finding on a petition to list a species, we 
evaluate whether the petition presents substantial scientific or 
commercial information indicating the subject species may be either 
threatened or endangered, as defined by the ESA. First, we evaluate 
whether the information presented in the petition, along with the 
information readily available in our files, indicates that the 
petitioned entity constitutes a ``species'' eligible for listing under 
the ESA. Next, we evaluate whether the information indicates that the 
species at issue faces extinction risk that is cause for concern; this 
may be indicated in information expressly discussing the species' 
status and trends, or in information describing impacts and threats to 
the species. We evaluate any information on specific demographic 
factors pertinent to evaluating extinction risk for the species at 
issue (e.g., population abundance and trends, productivity, spatial 
structure, age structure, sex ratio, diversity, current and historical 
range, habitat integrity or fragmentation), and the potential 
contribution of identified demographic risks to extinction risk for the 
species. We then evaluate the potential links between these demographic 
risks and the causative impacts and threats identified in ESA section 
4(a)(1).
    Information presented on impacts or threats should be specific to 
the species and should reasonably suggest that one or more of these 
factors may be operative threats that act or have acted on the species 
to the point that it may warrant protection under the ESA. Broad 
statements about generalized threats to the species, or identification 
of factors that could negatively impact a species, do not constitute 
substantial information that listing may be warranted. We look for 
information indicating that not only is the particular species exposed 
to a factor, but that the species may be responding in a negative 
fashion; then we assess the potential significance of that negative 
response.
    Many petitions identify risk classifications made by non-
governmental organizations, such as the International Union for the 
Conservation of Nature (IUCN), the American Fisheries Society, or 
NatureServe, as evidence of extinction risk for a species. Risk 
classifications by other organizations or made under other Federal or 
state statutes may be informative, but such classification alone may 
not provide the rationale for a positive 90-day finding under the ESA. 
For example, as explained by NatureServe, their assessments of a 
species' conservation status do ``not constitute a recommendation by 
NatureServe for listing under the U.S. Endangered Species Act'' because 
NatureServe assessments ``have different criteria, evidence 
requirements, purposes and taxonomic coverage than government lists of 
endangered and threatened species, and therefore these two types of 
lists should not be expected to coincide'' (http://www.natureserve.org/prodServices/pdf/NatureServeStatusAssessmentsListing-Dec%202008.pdf). 
Thus, when a petition cites such classifications, we will evaluate the 
source of information that the classification is based upon in light of 
the standards on extinction risk and impacts or threats discussed 
above.

Species Description

Distribution

    The bigeye thresher shark (Alopias superciliosus) is a large, 
highly migratory oceanic and coastal species of shark found throughout 
the world in tropical and temperate seas. In the Western Atlantic 
(including the Gulf of Mexico), bigeye threshers can be found off the 
Atlantic coast of the United States (from New York to Florida), and in 
the Gulf of Mexico off Florida, Mississippi and Texas. They can also be 
found in Mexico (from Veracruz to Yucatan), Bahamas, Cuba, Venezuela, 
as well as central and southern Brazil. In the Eastern Atlantic, bigeye 
threshers are found from Portugal to the Western Cape of South Africa, 
including the western and central Mediterranean Sea. In the Indian 
Ocean, bigeye threshers are found in South Africa (Eastern Cape and 
KwaZulu-Natal), Madagascar, Arabian Sea (Somalia), Gulf of Aden, 
Maldives, and Sri Lanka. In the Pacific Ocean, from West to East, 
bigeye threshers are known from southern Japan (including Okinawa), 
Taiwan (Province of China), Vietnam, between the Northern Mariana 
Islands and Wake Island, down to the northwestern coast of Australia 
and New Zealand. Moving to the Central Pacific, bigeye threshers are 
known from the area between Wake, Marshall, Howland and Baker, Palmyra, 
Johnston, Hawaiian Islands, Line Islands, and between Marquesas and 
Galapagos Islands. Finally, in the Eastern Pacific, bigeye threshers 
occur from Canada to Mexico (Gulf of California) and west of Galapagos 
Islands (Ecuador). They are also possibly found off Peru and northern 
Chile (Compagno, 2001).

Physical Characteristics

    The bigeye thresher shark possesses an elongated upper caudal lobe 
almost equal to its body length, which is unique to the Alopiidae 
family. It has a broad head, a moderately long and bulbous snout, 
curved yet broad-tipped pectoral fins, distinctive grooves on the head 
above the gills, and large teeth. The first dorsal fin mid base is 
closer to the pelvic-fin bases than to the pectoral-fin bases. The 
caudal tip is broad with a wide terminal lobe. While some of the above 
characteristics may be shared by

[[Page 48063]]

other thresher shark species, diagnostic features separating this 
species from the other two thresher shark species (common thresher, A. 
vulpinus, and pelagic thresher, A. pelagicus) are their extremely large 
eyes, which extend onto the dorsal surface of the head, and the 
prominent notches that run dorso-lateral from behind the eyes to behind 
the gills. The body can be purplish grey or grey-brown on the upper 
surface and sides, with grey to white coloring on its underside (light 
color of abdomen does not extend over pectoral fin bases like common 
thresher) and no white dot on upper pectoral fin tips like those often 
seen in common threshers (Compagno 2001).

Habitat

    Bigeye thresher sharks are found in a diverse spectrum of 
locations, including coastal waters over continental shelves, on the 
high seas in the epipelagic zone far from land, in deep waters near the 
bottom on continental slopes, and sometimes in shallow inshore waters. 
They are an epipelagic, neritic, and epibenthic shark, ranging from the 
surface and in the intertidal to at least 500 m deep, but mostly below 
100 m depth. In our files, we found information indicating that bigeye 
threshers prefer an optimum swimming depth of 240-360 m, water 
temperature of 10-16 [deg]C, salinity of 34.5-34.7 ppt, and dissolved 
oxygen range between 3.0-4.0 ml/l (Cao et al., 2011).

Feeding Ecology

    Bigeye threshers feed on small to medium sized pelagic fishes 
(e.g., lancetfishes, herring, mackerel and small billfishes), bottom 
fishes (e.g., hake), and cephalopods (e.g., squids). Thresher sharks 
are unique in that they use their tail in a whip-like fashion to 
disorient and incapacitate their prey prior to consumption (Oliver, 
2013). The arrangement of the eyes, with keyhole-shaped orbits 
extending onto the dorsal surface of the head, suggest that this 
species has a dorsal/vertical binocular field of vision (unlike other 
threshers), which may be related to fixating on prey and striking them 
with its tail from below (FAO 2015 species fact sheet).

Life History

    Bigeye thresher sharks have an estimated lifespan of approximately 
20-21 years and a maximum total length of about 4.6 m. Maturity in 
bigeye threshers occurs at 7-13 years and 275-300 cm total length (TL) 
for males and 8-15 years and 290-341cm (TL) for females. Bigeye 
threshers have low reproductive capacity of only 2-4 pups per litter 
(Chen et al., 1997; Compagno, 2001; Moreno and Mor[oacute]n, 1992) and 
a long gestation period of 12 months, although this remains uncertain 
due to a lack of birthing seasonality data (Liu et al., 1998). They 
(like all thresher sharks) are ovoviviparous and oophagous (developing 
embryo in uteri eat unfertilized eggs produced by the ovary). Size at 
birth for the bigeye thresher ranges from 64-106 cm TL (Gilmore, 1993), 
but a mating season has not yet been identified. Bigeye threshers have 
the slowest population growth rate of all thresher sharks, with an 
exceptionally low potential annual rate of population increase (0.02; 
IUCN; [lambda]=1.009 yr-1, Cort[eacute]s, 2009).

Analysis of Petition and Information Readily Available in NMFS Files

    Below we evaluate the information provided in the petition and 
readily available in our files to determine if the petition presents 
substantial scientific or commercial information indicating that an 
endangered or threatened listing may be warranted as a result of any of 
the factors listed under section 4(a)(1) of the ESA. If requested to 
list a global population or, alternatively, a DPS, we first determine 
if the petition presents substantial information that the petitioned 
action is warranted for the global population. If it does, then we make 
a positive finding on the petition and conduct a review of the species 
range-wide. If after this review we find that the species does not 
warrant listing range-wide, then we will consider whether the 
populations requested by the petition qualify as DPSs and warrant 
listing. If the petition does not present substantial information that 
the global population may warrant listing, but it has requested that we 
list any distinct populations of the species as threatened or 
endangered, then we consider whether the petition provides substantial 
information that the requested population(s) may qualify as DPSs under 
the discreteness and significance criteria of our joint DPS Policy, and 
if listing any of those DPSs may be warranted. We summarize our 
analysis and conclusions regarding the information presented by the 
petitioners and in our files on the specific ESA section 4(a)(1) 
factors that we find may be affecting the species' risk of global 
extinction below.

Bigeye Thresher Shark Status and Trends

    The petition does not provide a population abundance estimate for 
bigeye thresher sharks, but points to its ``vulnerable'' status on the 
IUCN Red List. The petition asserts that a global decline of bigeye 
thresher sharks has been caused mainly by commercial and recreational 
fishing (both direct harvest and bycatch), as evidenced by substantial 
population declines in every area where sufficient historical and 
current population data exist. In the Northwest and Western Central 
Atlantic, the petition cites an 80 percent decline in bigeye thresher 
sharks since the early 2000s, with an estimated average overall decline 
of 63 percent since the beginning of data collection in 1986. In the 
Southwest Atlantic, the petition describes the popularity of bigeye 
threshers in the Brazilian Santos longline fishery, and asserts that 
some vessels are directly targeting this species specifically for its 
fins. The petition also describes consistent gradual decreases in catch 
per unit effort (CPUE) for this species in the region. The petition 
describes likely declines of bigeye thresher sharks in the 
Mediterranean based on declines of other pelagic shark species, 
including congener A. vulpinus, due to high fishing pressure. In the 
Indo-West Pacific, the petition cites the prevalence of finning 
activities, including both legal and extensive illegal directed shark 
catch in this region, and states that the bigeye thresher in particular 
is preferentially retained in certain fisheries. In the Eastern Central 
Pacific, the petition cites 83 percent declines in thresher populations 
when compared to research surveys from the 1950s. Finally, the petition 
points to increased interest in recreational fishing of the bigeye 
thresher shark, with the potential for high post-release mortality. The 
petition does not provide information on abundance estimates across the 
global range of the species.
    The last IUCN assessment of the bigeye thresher shark was completed 
in 2009, and several estimates of global and subpopulation trends and 
status have been made and are described in the following text. In the 
Northwest Atlantic, declines in relative abundance cited by the 
petitioner were derived from analyses of logbook data, reported in Baum 
et al., (2003) and Cort[eacute]s (2007). The former study analyzed 
logbook data for the U.S. pelagic longline fleets targeting swordfish 
and tunas in the Northwest Atlantic, and reported an 80 percent decline 
in relative abundance for thresher sharks (common and bigeye threshers 
combined) from 1986 to 2000. The latter study reported a 63 percent 
decline of thresher sharks (at the genus level) based on logbook data, 
occurring between 1986 and 2006 (Cort[eacute]s, 2007). However, the 
observer index data from the same study (Cort[eacute]s, 2007) shows an

[[Page 48064]]

opposite trend in relative abundance, with a 28 percent increase of 
threshers in the Northwest Atlantic since 1992. Logbook data over the 
same period (1992-2006) shows a 50 percent decline in thresher sharks. 
The logbook dataset is the largest available for the western North 
Atlantic Ocean, but the observer dataset is generally more reliable in 
terms of consistent identification and reporting. According to observer 
data, relative abundance of thresher sharks (again, only at the genus 
level) in the western North Atlantic Ocean appears to have stabilized 
or even be increasing since the late 1990s (Cort[eacute]s, 2007). A 
more recent analysis using logbook data between 1996 and 2005 provides 
some supporting evidence that the abundance of thresher sharks has 
potentially stabilized over this time period (Baum and Blanchard, 
2010). However, it should be noted that fishing pressure on thresher 
sharks began over two decades prior to the start of this time series; 
thus, the estimated declines are not from virgin biomass. Furthermore, 
the sample size in the latter observer analysis was also very small 
compared to the previous logbook analyses, which both showed declines. 
Thus, abundance trend estimates derived from standardized catch rate 
indices of the U.S. pelagic longline fishery suggest that thresher 
sharks (both bigeye and common) have likely undergone a decline in 
abundance in this region. However, the conflicting evidence between 
logbook and observer data showing opposite trends in thresher shark 
abundance cannot be fully resolved at this time. Data are not available 
in the petition or in our own files to assess the trend in population 
abundance in this region since 2006, or to assess the trend specific to 
the bigeye thresher shark. Because the logbook data from this region 
show consistent evidence of a significant and continued decline in 
thresher sharks, we must consider this information in our 90-day 
determination. Additionally, in the Southeastern United States, studies 
show significant declines in the species, with decreases in CPUE 
indicating that the population of A. superciliosus has declined by 70 
percent from historical levels (Beerkircher et al., 2002).
    For the Northeast Atlantic, there are no population abundance 
estimates available, but data indicate that the species is taken in 
driftnets and gillnets. In the Mediterranean Sea, estimates show 
significant declines in thresher shark abundance during the past two 
decades, reflecting data up to 2006. According to historical data 
compiled using a generalized linear model, thresher sharks have 
declined between 96 and 99 percent in abundance and biomass in the 
Mediterranean Sea (Ferretti et al., 2008). Overall, the bigeye thresher 
shark has been poorly documented in the Mediterranean and is considered 
scarce or rare.
    In the Eastern Central Pacific, logbook data show a historical 
decline of thresher sharks due to pelagic fishing fleet operations. 
Trends in abundance and biomass of thresher sharks in the eastern 
tropical Pacific Ocean were estimated by comparison of pelagic longline 
research surveys in the 1950s with recent data (1990s); these data were 
collected by observers on pelagic longline fishing vessels and 
standardized to account for differences in depth and soak time. This 
analysis estimated a decline in combined thresher abundance of 83 
percent and a decline in biomass to approximately 5 percent of virgin 
levels (Ward and Myers, 2005).
    In other areas of the world, estimates of thresher shark abundance 
are limited. Bigeye threshers are recorded in the catches of fisheries 
operating in the Indo-West Pacific, but catches of the species are 
likely very under-reported. An analysis of purse seine and longline 
observer data from the Western and Central Pacific produced no clear 
catch trends for thresher sharks (Alopias spp.); however, shark data 
from observer data sets are constrained by a lack of observer coverage, 
particularly for the North Pacific, and for the purse seine fishery by 
the physical practicalities of onboard sampling (Clarke, 2011). 
Additionally, this study detected a significant decrease in median size 
for thresher sharks in tropical areas, most likely reflective of trends 
in bigeye threshers as they are the most commonly encountered species 
in this region. While catch data are incomplete and cannot be used to 
estimate abundance levels or determine the magnitude of catches or 
trends for bigeye threshers at this time, pelagic fishing effort in 
this region is high, with reported increases in recent years (IUCN 
assessment, 2009).
    In conclusion, across the species' global range we find evidence 
suggesting that population abundance of the bigeye thresher shark is 
declining or, in the Northwest Atlantic Ocean, may be stable at a 
diminished abundance. While data are still limited with respect to 
population size and trends, we find the petition and our files 
sufficient in presenting substantial information on bigeye thresher 
shark abundance, trends, or status to indicate the petitioned action 
may be warranted.

ESA Section 4(a)(1) Factors

    The petition indicated three main categories of threats to the 
bigeye thresher shark: overutilization for commercial, recreational, 
scientific, or educational purposes; the inadequacy of existing 
regulatory mechanisms; and other natural or manmade factors affecting 
its continued existence. We discuss each of these below based on 
information in the petition, and the information readily available in 
our files.

Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petition states that ``the bigeye thresher has shown 
substantial population declines in every area where sufficient 
historical and current population data exists'' and lists four 
categories of overutilization: historical, directed, incidental, and 
recreational. The petition describes historical exploitation as the 
first category of overutilization for the species, predominantly in the 
Northwest and Central Atlantic and Eastern Central Pacific. In the 
Northwest and Central Atlantic, bigeye threshers were historically 
caught in pelagic longline fisheries. Bigeye threshers have been a 
prohibited species in all commercial fisheries in the U.S. Atlantic 
since 2000. Since these regulations became effective in 2000, relative 
abundance of thresher sharks (again, only at the genus level) in the 
western North Atlantic Ocean appears to have stabilized or even be 
increasing since the late 1990s (Baum and Blanchard, 2010; 
Cort[eacute]s, 2007). However, it should be noted that bigeye threshers 
are still caught as bycatch and occasionally landed in the Northwest 
Atlantic Ocean despite its prohibited status (NMFS, 2012; 2013), which 
may hinder the ability of the population to rebound from the historical 
declines.
    As previously mentioned, the petition also states that logbook data 
from the Eastern Central Pacific shows a historical decline of bigeye 
thresher sharks due to pelagic fishing fleet operations known to take 
this species. Trends in abundance and biomass of thresher sharks in the 
eastern tropical Pacific Ocean were estimated by comparison of pelagic 
longline research surveys in the 1950s with recent data (1990s); these 
data were collected by observers on pelagic longline fishing vessels 
and standardized to account for differences in depth and soak time. For 
example, in the 1990's, longliners deployed more hooks (averaging 2240 
hooks per day compared to 322 hooks in the 1950s) over a wider depth 
range

[[Page 48065]]

(down to 600 m compared to 200 m) for longer periods. Thus, while 
catches of thresher sharks increased (from 112 threshers in the 1950s 
survey to 511 threshers in the 1990s survey), this analysis estimated a 
decline in combined thresher abundance of 83 percent, with a decline in 
mean biomass to approximately 5 percent of virgin levels and a decline 
in mean body mass from 17 kg to 12 kg). While this analysis was not 
species-specific (Ward and Myers, 2005), we must consider this 
information in our 90-day finding given the potential significant 
population decline of bigeye threshers in this region.
    In addition to broad commercial harvest of the species, the 
petition states that direct catch related to the shark fin trade has 
resulted in population decline, and that bigeye thresher sharks are 
targeted and preferentially retained for their fins. For example, the 
petition stated in the Indo-West Pacific, a single thresher fin can 
fetch US $250, creating incentives that would drive overutilization. 
However, this statement is not entirely correct. While it is true that 
high prices are paid for thresher sharks, the value of US $250 was not 
for a single fin, but rather for the entire shark (Gilman et al., 
2007). Still, in comparison to other sharks (e.g., shortfin mako only 
fetches US $50 per shark), thresher sharks appear to be highly valued 
and consequently targeted for both their meat and fins. While the 
petition did not provide any information connecting population declines 
as a result of this direct catch, evidence suggests that the three 
thresher shark species, collectively, may account for approximately 2.3 
percent of the fins auctioned in Hong Kong, the world's largest fin-
trading center (Clarke, 2006). This translates to 0.4 million to 3.9 
million threshers that may enter the global fin trade each year 
(Clarke, 2006), with bigeye thresher having the highest value and 
vulnerability to fishing compared to the other thresher species 
(Cort[eacute]s, 2010); still, the relative proportion of each thresher 
shark species comprising the shark fin trade is not available in this 
genus-level assessment and information on the species-specific impact 
of this harvest on bigeye thresher shark abundance is not provided by 
the petitioner. However, we found species-specific evidence in our 
files that bigeye threshers may be highly utilized in the shark fin 
trade. In a genetic barcoding study of shark fins from markets in 
Taiwan, bigeye threshers were one of 20 species identified and 
comprised 0.07 percent of collected fin samples. Additionally, thresher 
sharks comprised 15 percent of fins genetically tested from markets 
throughout Indonesia (the largest shark catching country in the world), 
with bigeye threshers making up an estimated 7.6 percent of all fins 
tested. The high frequency of bigeye threshers in the markets across 
Indonesia provides some evidence that they are not just caught 
incidentally, but are targeted by large-scale fisheries (Sembiring, 
2015). In another genetic barcoding study of fins from United Arab 
Emirates, the fourth largest exporter in the world of raw dried shark 
fins to Hong Kong, the authors found that the Alopiidae family 
represented 5.9 percent of the trade from Dubai, with bigeye thresher 
comprising 2.31 percent (Jabado et al., 2015). Overall, evidence that 
bigeye thresher sharks (and threshers in general) are highly valued for 
their fins, are possibly targeted in some areas, and comprise a portion 
of the Hong Kong fin-trading auction suggests that this threat may 
impact the species.
    In the Indian Ocean, the status and abundance of shark species is 
poorly known despite a long history of research and more than 60 years 
of commercial exploitation by large-scale tuna fisheries (Romanov et 
al., 2010). Pelagic sharks, including bigeye threshers, are targeted in 
various fisheries, including semi-industrial, artisanal, and 
recreational fisheries. Countries that fish for various pelagic species 
of sharks include: Egypt, India, Iran, Oman, Saudi Arabia, Sudan, 
United Arab Emirates, and Yemen, where the probable or actual status of 
shark populations is unknown, and Maldives, Kenya, Mauritius, 
Seychelles, South Africa, and United Republic of Tanzania, where the 
actual status of shark populations is presumed to range from fully 
exploited to over-exploited (Young, 2006). In 2013, an Ecological Risk 
Assessment (ERA) was developed by the Indian Ocean Tuna Commission 
(IOTC) Scientific Committee to quantify which shark species are most at 
risk from the high levels of pelagic longline fishing pressure. In this 
ERA, the IOTC Scientific Committee noted that A. superciliosus received 
a high vulnerability ranking (No. 2) for longline gear, as the species 
is characterized as one of the least productive shark species, and is 
highly susceptible to catch in longline fisheries. The ERA also noted 
that the available evidence indicates considerable risk to the status 
of the Indian Ocean Alopias spp. stocks at current catch levels, which, 
from 2000-2011 was estimated to be 22,811 mt (Merua et al., 2013).
    Indirect catch is another category of overutilization identified by 
the petition, which states that post-release mortality may be high in 
the species. However, no information is provided in the petition to 
connect the effect of bycatch on population declines of the species. In 
the Northeast Atlantic and Mediterranean, while there are no target 
fisheries for thresher sharks, they are taken as bycatch in various 
fisheries, including the Moroccan driftnet fishery in the southwest 
Mediterranean. They are also caught by industrial and semi-industrial 
longline fisheries and by artisanal gillnet fisheries. In our files, we 
found evidence that in the last two decades, thresher sharks (common 
and bigeye) have declined between 96 and 99 percent in abundance and 
biomass in the Mediterranean Sea (Ferretti, 2008).
    Although bigeye thresher sharks have been a prohibited species in 
U.S. Atlantic commercial fisheries since 2000, they are still 
incidentally taken as bycatch on pelagic longlines and in gillnets on 
the East Coast. For example, in our files, we found that since the 
prohibition on bigeye threshers came into effect in 2000, approximately 
1,493 lbs, dressed weight (677 kg) of bigeye thresher were landed in 
the Atlantic (NMFS, 2012; 2014) despite its prohibited status. In 2010, 
the United States reported that bigeye thresher represented the second 
largest amount of dead discards in the Atlantic commercial fleet, 
reporting a total of 46 t (NOAA, 2010 Report to ICCAT). In 2011, this 
number dropped to 27 t of bigeye thresher dead discards (NOAA, 2011 
Report to ICCAT). Further, several recent reports assessing the 
vulnerability of bigeye threshers and other pelagic sharks to bycatch 
in the U.S. Atlantic pelagic longline fishery characterized the bigeye 
thresher as highly vulnerable (Cortes, 2010; Cortes, 2012; Gallagher et 
al., 2014). These landings and dead discards may be linked to declines 
in the species across the Northwest Atlantic portion of its range; 
however, as discussed earlier, conflicting logbook and observer data 
decrease the certainty of these trends (Cort[eacute]s, 2007; Baum and 
Blanchard, 2010).
    In the Southwest Atlantic Ocean, off the coast of Brazil, bigeye 
threshers represent almost 100 percent of thresher sharks caught in 
longline fisheries (Amorin, 1998). The landed catch and CPUE of bigeye 
thresher shark in this fishery increased from 1971 to 1989, and then 
gradually decreased from 1990 to 2001; however, this does not 
necessarily reflect stock abundance because changes in the depth of 
fishing operations also occurred, which may

[[Page 48066]]

have affected the time series. Thus, further information is needed to 
resolve this. In our files, we found that bigeye threshers are also 
taken in Uruguayan longline fisheries at similar levels. In one study, 
observer data from 2001-2005 recorded a total of 295 A. superciliosus 
specimens, in which the species' abundance was characterized as ``low'' 
despite high fishing effort (Berrondo et al., 2007). Further, observer 
data from 1992-2000 showed that bigeye threshers experience high 
mortality in longline fisheries in the Southwest Atlantic, with 54 
percent dead upon capture (Beerkircher et al., 2002). Given the 
declines reported in other areas for which data are available 
throughout other parts of the species' range and the high fishing 
pressure from fleets throughout the Southwest Atlantic, A. 
superciliosus may be experiencing a level of exploitation in this part 
of its range that may increase its risk of extinction.
    In the Eastern Central Pacific, the petition points to the fact 
that bigeye threshers have been recorded as bycatch in purse seine 
fleets operating in this region, in which bigeye threshers comprised 1 
percent of shark species caught during a Shark Characteristics Sampling 
Program conducted from 1994-2004 (Roman-Verdesoto and Orozco-
Z[ouml]ller, 2005). Bycatch for this report was defined as sharks that 
were discarded dead after being removed from the net and placed on the 
vessel. Since 2010, catches of thresher sharks in this fishery have 
fluctuated between 10 t and 14 t; however, in a preliminary 
productivity-susceptibility assessment, bigeye threshers were 
characterized as having a low susceptibility to this fishery (IAATC, 
2009). Complete bycatch and discard data are not readily available from 
longline fleets in the Eastern Pacific. In our files, we found that 
bigeye thresher sharks are minor components of U.S. West Coast 
fisheries, taken incidentally and presumably not overexploited, at 
least locally. The bigeye thresher occurs regularly but in low numbers, 
comprising only approximately 9 percent of common thresher catch (PFMC, 
2003). Overall, we found that apart from blue and silky sharks, there 
are no stock assessments available for shark species in the Eastern 
Pacific, and hence the impacts of bycatch on the population are unknown 
(IATTC, 2014). However, despite a lack of information regarding present 
levels of bycatch occurring in other fisheries throughout the Eastern 
Pacific, as described earlier, thresher sharks were estimated to have 
experienced an 83 percent decline in this part of the species' range as 
a result of fishing mortality in longline fisheries. Given the high 
rates of bycatch-related mortality observed in this species throughout 
other parts of its range (e.g., Northwest and Southwest Atlantic, 
Indian Ocean, and Central Pacific), it is likely the species 
experiences similar rates of bycatch-related mortality in this part of 
its range as well. Thus, it is likely that the historical and continued 
levels of exploitation in this part of the species' range are impacting 
the species, such that listing may be warranted.
    We found evidence that bigeye threshers are known to interact with 
longline fisheries throughout the Indo-Pacific. In the Western and 
Central Pacific, where sharks represent 25 percent of the longline 
fishery catch, observer data showed that bigeye thresher shark is the 
7th most commonly bycaught species of shark out of a total 49 species 
reported by observers (Molony, 2007). We found that bigeye threshers 
are commonly taken as bycatch in longline fisheries in the Republic of 
the Marshall Islands, in which they exhibit at-vessel and/or post-
release mortality of 50 percent, and nearly 99 percent are finned and 
subsequently discarded (Bromhead, 2012). Further, in a species status 
snapshot for thresher sharks in the Western and Central Pacific, Clarke 
et al., (2011) identified significant decreasing size trends for 
thresher sharks in tropical areas, which may be indicative of 
population declines in these areas. It is thought that these findings 
most likely reflect trends of bigeye threshers as they are the most 
common thresher species encountered in this region, with catches of 
common and pelagic threshers characterized as rare or uncommon. Bigeye 
threshers are also commonly caught by Hawaii longline fisheries, 
particularly on deep-set gear (Walsh et al., 2009), and represented 4.1 
percent of shark catches from 1995-2006. While catches of thresher 
sharks (Alopias spp.) have trended upward, actual landings of thresher 
sharks in Hawaii have decreased from 50 mt in 2001 to 16 mt in 2010, 
presumably due to the implementation of state and Federal laws 
regarding shark finning (NMFS, 2011).
    In the Indian Ocean, while fisheries are directed at other species, 
bigeye threshers are commonly caught as bycatch and catch rates are 
considered high (IOTC, 2011; Hererra and Pierre, 2011). For example, 
bycatch of bigeye threshers has been recorded in Japanese and Taiwanese 
longline fisheries. According to Japanese observer data, 162 bigeye 
threshers were bycaught in 6 months (from July 2010 to January 2011). 
These data do not include live-released bigeye thresher sharks (Ardill 
et al., 2011), which reportedly have high post-release mortality rates 
(IOTC, 2014). Observer data from Taiwanese longline fleets (with 
coverage ranging from only 2.2 percent in 2004 to 20.8 percent in 2007) 
recorded a total of 445 bigeye threshers bycaught from 2004-2008, with 
approximately 61 percent discarded (Huang and Liu, 2010). Hooking 
mortality is apparently very high in this region; therefore, the IOTC's 
regulation 10/12 that prohibits the onboard retention of any part of 
any thresher species and promotes live release of thresher sharks may 
be ineffective for the conservation of bigeye thresher sharks. For 
example, in the Portuguese longline fleet, bigeye threshers experienced 
a high rate of at-vessel mortality of 68.4 percent (n = 19) from May to 
September 2011 (Ardill et al., 2011). The IOTC reported in 2014 that 
``maintaining or increasing effort in this region will probably result 
in further declines in biomass, productivity and CPUE'' for bigeye 
threshers (IOTC, 2014).
    Overall, there is considerable uncertainty regarding the actual 
levels of bycatch of bigeye thresher shark occurring throughout its 
range; however, it is likely that these rates are significantly under-
reported due to a lack of comprehensive observer coverage in areas of 
its range in which the highest fishing pressure occurs, as well as a 
tendency for fishers to not record discards in fishery logbooks. 
Nevertheless, given the prevalence of bigeye threshers as incidental 
catch throughout its range and the species' observed high hooking and 
post-release mortality rates, combined with the species' low 
productivity, bycatch-related fishing mortality may be a threat placing 
the species at an increased risk of extinction.
    The petition identified recreational fishing as the fourth category 
of overutilization. In our files, we found evidence that thresher 
sharks, particularly common threshers, are valued by recreational sport 
fishermen throughout the species' U.S. East Coast and West Coast range; 
however, bigeye threshers do not appear to be as important in 
recreational fisheries and are largely prohibited in many fisheries 
within the United States. The petition described results from Heberer 
(2010), which identified the potential negative impact of recreational 
fishing on the survival of congener, A. vulpinus, by assessing post-
release survivorship of sharks captured using the caudal fin-based 
techniques used by most

[[Page 48067]]

recreational fishermen in southern California. As previously described, 
thresher sharks use their elongate upper caudal lobe to immobilize prey 
before it is consumed, and the majority of common thresher sharks 
captured in the southern California recreational fishery are hooked in 
the caudal fin and hauled-in backwards. This is significant because 
common threshers are obligate ram ventilators that require forward 
motion to ventilate the gills (Heberer, 2010), and the reduced ability 
to extract oxygen from the water during capture, as well as the stress 
induced from these capture methods, may influence recovery following 
release. The findings of Heberer (2010) demonstrate that large tail-
hooked common thresher sharks with prolonged fight times (>=85 min) 
exhibit a heightened stress response, which may contribute to an 
increased mortality rate. This work suggests, especially for larger 
thresher sharks, that recreational catch-and-release may not be an 
effective conservation-based strategy for the species. A recent paper 
by Sepulveda (2014) found similar evidence for high post-release 
mortality of recreationally caught common thresher sharks in the 
California recreational shark fishery. Their results demonstrated that 
caudal fin-based angling techniques, which often result in trailing 
gear left embedded in the shark, can negatively affect post-release 
survivorship. This work suggests that mouth-based angling techniques 
can, when performed properly, result in a higher survivorship of 
released sharks. The petition argues that because common thresher 
sharks may exhibit high mortality in recreational fisheries that bigeye 
threshers would likely exhibit similar results. While this may be true, 
in our files, we found no evidence to suggest that bigeye threshers are 
declining (or responding in a negative fashion) as a result of 
utilization by recreational fisheries. While it is not known if this 
species enters the California recreational fishery on any regular 
basis, presumably only few are taken. Further, there are no records 
from the recreational fishery off Oregon or Washington (NMFS, 2007), 
and in fact, fishing of all thresher species is prohibited in 
Washington. Likewise, in the Northwest Atlantic, bigeye threshers have 
been prohibited in recreational fisheries by Federal regulations since 
1999. Further, U.S. states from Maine to Florida have adopted the 
Interstate Fisheries Management Plan (FMP) for Atlantic Coastal Sharks 
adopted by the Atlantic States Marine Fisheries Commission (ASMFC), 
which prohibits recreational fishing of bigeye threshers. Finally, 
since prohibition of this species was implemented in 1999, there has 
been no observed recreational harvest of this species, with the 
exception of years 2002 and 2006 (NMFS, 2014). The petition did not 
provide, nor could we find in our files, any information regarding the 
threat of recreational fishing to bigeye threshers throughout the rest 
of the species' range. Thus, we find that the information presented in 
the petition, and in our files, does not comprise substantial 
information that would lead us to conclude the species may have an 
increased risk of extinction from overutilization as a result of 
recreational fishing activities.
    Overall, trends in the North West and Central Atlantic Ocean 
suggest that the species experienced historical declines from 
overexploitation, but may be stabilized and possibly increasing in 
recent years, although there is considerable uncertainty regarding 
these trends. Elsewhere across the species' range, information in the 
petition and in our files suggests that the species may continue to 
experience declines as a result of overutilization from both direct and 
indirect fishing pressure. In summary, the petition, references cited, 
and information in our files comprise substantial information 
indicating that listing may be warranted because of overutilization for 
commercial purposes.

Inadequacy of Existing Regulatory Mechanisms

    The petition points to ``virtually non-existent international 
regulatory protections'' to assert that bigeye threshers qualify for 
listing due to the inadequacy of existing regulatory mechanisms. For 
example, the petition mentions the lack of protections from the 
Convention on International Trade of Endangered Species (CITES) for the 
bigeye thresher shark, but then states that even if the species was 
listed under CITES, it would still be inadequate due to the fact that a 
CITES listing would only address threats associated with the 
international trade of the species, and would not address such impacts 
as bycatch. Although a CITES Appendix II listing or international 
reporting requirements would provide better data on the global catch 
and trade of the bigeye thresher shark, the lack of a CITES listing or 
requirements does not suggest that current regulatory mechanisms are 
inadequate to protect the bigeye thresher shark population from 
becoming threatened or endangered under the ESA. The petition also 
asserts that the recent listing of bigeye thresher shark under Appendix 
II of the Convention of Migratory Species (CMS) is also inadequate 
given that the United States and other range states are not Member 
Parties to CMS and are therefore not bound by the requirements imposed 
by the Appendix II listing. The petition further states that the 
Convention text is only suggestive and not self-executing upon the 
listing of a species. On the contrary, we find that a CMS Appendix II 
listing now encourages international cooperation towards conservation 
of the species, and although the United States is not currently a party 
to CMS, the United States is a signatory to a number of CMS instruments 
for the conservation of various marine species, including sharks.
    The petition also asserts that finning regulations and species-
specific retention bans are ``inadequate'' for protecting the bigeye 
thresher shark species because they may still be caught, either 
directly or indirectly. The petition also cites several regional 
fisheries management organizations (RFMOs) that implement a 5 percent 
fin-to-carcass ratio regulation, describes what the petitioner contends 
are potential loopholes in those regulations, and states that these 
general regulations are inadequate for the bigeye thresher shark, whose 
larger fins make it a more targeted species. The petition further 
contends that species-specific retention bans for bigeye threshers, 
such as the ones implemented by ICCAT and IOTC that specifically 
prohibit the retention, transshipping, landing, storing, selling, or 
offering for sale any part or whole carcass of bigeye thresher sharks, 
are also inadequate largely because they do not address incidental 
catch and subsequent high mortality rates of the species. Based on the 
information presented in the petition and in our files, we find that 
the bigeye thresher shark is highly valued for its fins, and can be 
identified in the shark fin market at the species level. While 
regulations banning the finning of sharks are a common form of shark 
management and have been adopted by far more countries and regional 
fishery management organizations than the petition lists (see HSI, 
2012), we agree with the petition that due to high rates of hooking 
mortality observed in this species as a result of incidental catch, 
prohibitions on the retention of bigeye thresher or restrictions on the 
finning of sharks may not be adequate to protect the bigeye thresher 
from fishing mortality rates that may contribute to its extinction 
risk, especially given the species' significantly low productivity and 
intrinsic rate of population increase.

[[Page 48068]]

    In addition to the inadequacy of international regulations, the 
petition states that ``while the U.S. has attempted to protect the 
bigeye thresher shark in U.S. waters, piecemeal protections that fail 
to cover the species throughout its migratory range have proven to be 
unsuccessful.'' Though U.S. regulations by their jurisdictional nature 
only cover U.S. fishers, we do not agree that this makes them 
inadequate. We find that U.S. national fishing regulations include 
numerous regulatory mechanisms for both sharks in general, and bigeye 
threshers specifically, that may help protect the species. For example, 
in the U.S. Atlantic, the bigeye thresher has been a prohibited species 
in both commercial and recreational fisheries since 2000 and 1999, 
respectively, under the 1999 Fishery Management Plan for Atlantic 
Tunas, Swordfish, and Sharks. In addition, current management measures 
for the Atlantic shark fisheries include the following: commercial 
quotas, commercial retention limits, limited entry, time-area closures, 
and recreational bag limits. Sharks are required to be landed with fins 
naturally attached to the carcass. Additionally, several U.S. states 
have prohibited the sale or trade of shark fins/products as well, 
including Hawaii, Oregon, Washington, California, Illinois, Maryland, 
Delaware, New York, and Massachusetts, subsequently decreasing the 
United States' contribution to the fin trade. For example, after the 
state of Hawaii prohibited finning in its waters in 2000 and required 
shark fins to be landed with their corresponding carcasses in the 
state, shark fin imports from the United States into Hong Kong declined 
significantly (54 percent decrease, from 374 to 171 tonnes), as Hawaii 
could no longer be used as a fin trading center for the international 
fisheries operating and finning in the Central Pacific (Miller, 2014). 
Except for smooth dogfish (Mustelus canis), the U.S. Shark Conservation 
Act of 2010 protects all shark species, making it illegal to remove any 
of the fins of a shark (including the tail) at sea; to have custody, 
control, or possession of any such fin aboard a fishing vessel unless 
it is naturally attached to the corresponding carcass; to transfer any 
such fin from one vessel to another vessel at sea, or to receive any 
such fin in such transfer, without the fin naturally attached to the 
corresponding carcass; or to land any such fin that is not naturally 
attached to the corresponding carcass, or to land any shark carcass 
without such fins naturally attached. However, we do agree with the 
petition that these regulations do not address the issue of bycatch-
related mortality of the species, especially considering the fact that 
bigeye threshers are still bycaught in U.S. fisheries.
    Overall, while measures may be implemented to reduce bycatch, we 
found no evidence that these measures have been incorporated into 
common practice throughout the species' range, particularly in areas 
where fishing pressure is most concentrated. Further, while numerous 
finning and species-specific retention bans have been implemented, 
these regulations fail to address the species' high rate of bycatch-
related mortality. In summary, the petition, references cited, and 
information in our files comprise substantial information indicating 
that the species may be impacted by the inadequacy of regulatory 
mechanisms in parts of its range, such that listing may be warranted.

Other Natural or Manmade Factors Affecting Its Existence

    The petition states that the biological constraints of the bigeye 
thresher shark, such as its low reproduction rate (typically 2-4 pups a 
year), coupled with a late age of maturity (approximately 12-14 years 
for females, and slightly earlier for males, between 9-10 years) 
contribute to the species' vulnerability to harvesting and its 
inability to recover rapidly. We agree with the petition that the 
bigeye thresher shark exhibits relatively slow growth rates and low 
fecundity. An ecological risk assessment conducted to inform the 
International Commission for the Conservation of Atlantic Tunas (ICCAT) 
categorized the relative risk of overexploitation of the 11 major 
species of pelagic sharks, including the bigeye thresher shark 
(Cort[eacute]s et al., 2010, 2012). The study derived an overall 
vulnerability ranking for each of the 11 species, which was defined as 
``a measure of the extent to which the impact of a fishery [Atlantic 
longline] on a species will exceed its biological ability to renew 
itself'' (Cort[eacute]s et al., 2010, 2012). This robust assessment 
found that bigeye thresher sharks have a combination of low 
productivity and high susceptibility to pelagic longline gear, which 
places the bigeye thresher at high risk of overexploitation to the 
combined pelagic longline fisheries in the Atlantic Ocean 
(Cort[eacute]s et al., 2010, 2012). In fact, of the 11 species examined 
in this study, Atlantic bigeye thresher sharks were identified as one 
of the most vulnerable and least productive shark species. Even within 
the genus Alopias, the bigeye thresher shark has the slowest population 
growth rate of all thresher sharks, with an exceptionally low potential 
annual rate of population increase (0.002-0.009 or 1.6 percent) under 
sustainable exploitation (Cort[eacute]s, 2008; Dulvy et al., 2008; 
Smith et al., 2008). This makes them particularly vulnerable to any 
level of fisheries exploitation, whether targeted or caught as bycatch 
in fisheries for other species. Given that bigeye thresher sharks are 
caught regularly as incidental bycatch throughout its range and 
experience high mortality rates as a result, and that the species may 
be targeted in some areas for its fins, the species' growth and 
reproductive factors may inhibit the species' ability to recover from 
even moderate levels of exploitation, thus placing the bigeye thresher 
shark at an increased risk of extinction as a result. In summary, the 
petition, references cited, and information in our files comprise 
substantial information indicating that the species is impacted by 
``other natural or manmade factors,'' including the life history trait 
of slow productivity, such that listing the species may be warranted.

Summary of Section 4(a)(1) Factors

    We conclude that the petition does not present substantial 
scientific or commercial information indicating that the ESA section 
(4)(a)(1) threats of ``present or threatened destruction, modification, 
or curtailment of its habitat or range'' or ``disease or predation'' 
may be causing or contributing to an increased risk of extinction for 
the global population of the bigeye thresher shark. However, we do 
conclude that the petition and information in our files present 
substantial scientific or commercial information indicating that the 
section 4(a)(1) factor ``overutilization for commercial, recreational, 
scientific, or educational purposes,'' as well as ``inadequacy of 
existing regulatory mechanisms'' and ``other manmade or natural 
factors,'' may be causing or contributing to an increased risk of 
extinction for the species.

Petition Finding

    Based on the above information and the criteria specified in 50 CFR 
424.14(b)(2), we find that the petition and information readily 
available in our files present substantial scientific and commercial 
information indicating that the petitioned action of listing the bigeye 
thresher shark worldwide as threatened or endangered may be warranted. 
Therefore, in accordance with section 4(b)(3)(A) of the ESA and NMFS' 
implementing regulations (50

[[Page 48069]]

CFR 424.14(b)(3)), we will commence a status review of the species. 
During the status review, we will determine whether the species is in 
danger of extinction (endangered) or likely to become so within the 
foreseeable future (threatened) throughout all or a significant portion 
of its range. We now initiate this review, and thus, we consider the 
bigeye thresher shark to be a candidate species (69 FR 19975; April 15, 
2004). Within 12 months of the receipt of the petition (April 27, 
2016), we will make a finding as to whether listing the species as 
endangered or threatened is warranted as required by section 4(b)(3)(B) 
of the ESA. If listing the species is found to be warranted, we will 
publish a proposed rule and solicit public comments before developing 
and publishing a final rule.

Information Solicited

    To ensure that the status review is based on the best available 
scientific and commercial data, we are soliciting information relevant 
to whether the bigeye thresher shark is endangered or threatened. 
Specifically, we are soliciting information in the following areas: (1) 
Historical and current distribution and abundance of this species 
throughout its range; (2) historical and current population trends; (3) 
life history in marine environments, including identified nursery 
grounds; (4) historical and current data on bigeye thresher shark 
bycatch and retention in industrial, commercial, artisanal, and 
recreational fisheries worldwide; (5) historical and current data on 
bigeye thresher shark discards in global fisheries; (6) data on the 
trade of bigeye thresher shark products, including fins, jaws, meat, 
and teeth; (7) any current or planned activities that may adversely 
impact the species; (8) ongoing or planned efforts to protect and 
restore the species and its habitats; (9) population structure 
information, such as genetics data; and (10) management, regulatory, 
and enforcement information. We request that all information be 
accompanied by: (1) Supporting documentation such as maps, 
bibliographic references, or reprints of pertinent publications; and 
(2) the submitter's name, address, and any association, institution, or 
business that the person represents.

References Cited

    A complete list of references is available upon request to the 
Office of Protected Resources (see ADDRESSES).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: August 5, 2015.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
[FR Doc. 2015-19551 Filed 8-10-15; 8:45 am]
 BILLING CODE 3510-22-P