[Federal Register Volume 77, Number 216 (Wednesday, November 7, 2012)]
[Notices]
[Pages 66799-66818]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-27244]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[Docket No. 100322160-2479-02]
RIN 0648-XV10
Endangered and Threatened Wildlife and Plants: Notice of 12-Month
Finding on a Petition To List the Bumphead Parrotfish as Threatened or
Endangered Under the Endangered Species Act (ESA)
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of twelve-month finding listing determination and
availability of status review documents.
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SUMMARY: We, NMFS, announce a twelve-month finding and listing
determination on a petition to list the bumphead parrotfish
(Bolbometopon muricatum) as threatened or endangered under the
Endangered Species Act (ESA). We have completed a status review of the
bumphead parrotfish in response to the petition submitted by WildEarth
Guardians and considered the best scientific and commercial data
available. The bumphead parrotfish is a coral reef-associated species
that occurs in 45 countries in the Indo-Pacific area, including some
U.S. Territories. After reviewing the best scientific and commercial
data available, we have determined that the bumphead parrotfish is not
warranted for listing under the ESA because the species still occupies
its historical range, although at a lower and declining abundance, but
with biological characteristics and management measures that support
the population above the viability threshold. Based on these
considerations, described in more detail in this notice, we conclude
that the bumphead parrotfish is not currently in danger of extinction
throughout all or a significant portion of its range, and not
[[Page 66800]]
likely to become so within the foreseeable future.
DATES: This finding was made on November 7, 2012.
ADDRESSES: The Bumphead parrotfish status review documents (Biological
Review Team Report, Management Report) are available by submitting a
request to the Regulatory Branch Chief, Protected Resources Division,
NMFS Pacific Islands Regional Office, 1601 Kapiolani Blvd., Suite 1110,
Honolulu, HI 96814, Attn: Bumphead Parrotfish 12-month Finding. The
reports are also available electronically at: http://www.fpir.noaa.gov/PRD/prd_esa_section_4.html.
FOR FURTHER INFORMATION CONTACT: Lance Smith, NMFS Pacific Islands
Regional Office, (808) 944-258; or Dwayne Meadows, NMFS, Office of
Protected Resources (301) 427-8403.
SUPPLEMENTARY INFORMATION:
Background
On January 4, 2010, we received a petition from WildEarth Guardians
to list the bumphead parrotfish (Bolbometopon muricatum) as threatened
or endangered under the Endangered Species Act of 1973. The petitioner
also requested that critical habitat be designated for this species
concurrent with listing under the ESA. The petition asserted that
overfishing is a significant threat to bumphead parrotfish and that
this species is declining across its range and is nearly eliminated
from many areas. The petition also asserted that degradation of coral
habitat through coral bleaching and ocean acidification threatens this
species as coral is its primary food source. The petition also argued
that biological traits (e.g., slow maturation and low reproductive
rates), shrinking remnant populations and range reductions, effects
from increasing human populations, and inadequate regulatory protection
all further contribute to the risk of extinction for bumphead
parrotfish. This species is listed as vulnerable by the International
Union for the Conservation of Nature (IUCN; Chan et al., 2007).
On April 2, 2010, we published a 90-day finding with our
determination that the petition presented substantial scientific and
commercial information indicating that the petitioned action may be
warranted (75 FR 16713). We initiated a comprehensive status review of
bumphead parrotfish to determine if the species warrants listing under
the ESA. The 90-day finding requested scientific and commercial
information from the public to inform a status review of the species.
We received ten public responses to the 90-day Finding; the information
we received was considered in the comprehensive status review as
described below in the Biological Review section. The status review of
bumphead parrotfish was completed jointly by our Pacific Islands
Fisheries Science Center (PIFSC) and Pacific Islands Regional Office
(PIRO). A Bumphead Parrotfish Biological Review Team (BRT) comprising
Federal scientists from the Hawaii Cooperative Fishery Research Unit of
the United States Geological Survey, and our Southwest and Pacific
Islands Fisheries Science Centers completed a biological report on the
species (hereafter ``BRT Report'', cited as Kobayashi et al., 2011).
PIRO staff completed a report on the regulatory mechanisms and
conservation efforts affecting the species across its range (hereafter
``Management Report'', cited as NMFS, 2012). The BRT Report and
Management Report together constitute the bumphead parrotfish status
review. Both reports are available as described above [see ADDRESSES].
Listing Determinations Under the ESA
We are responsible for determining whether the bumphead parrotfish
is threatened or endangered under the ESA (16 U.S.C. 1531 et seq.).
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 to protect the species. We have followed a four-step approach in
making this listing determination for bumphead parrotfish: (1)
Biological Review; (2) Threats Evaluation; (3) Extinction Risk
Analysis; and (4) Listing Determination.
For the first step, the BRT completed a biological review of the
taxonomy, distribution, abundance, life history and biology of the
species (Kobayashi et al., 2011). The BRT Report determined if the
bumphead parrotfish is a ``species'' under the ESA. To be considered
for listing under the ESA, a group of organisms must constitute a
``species,'' which is defined in section 3 of the ESA to include
taxonomic species plus ``any subspecies of fish or wildlife or plants,
and any distinct population segment [DPS] of any species of vertebrate
fish or wildlife which interbreeds when mature.'' The BRT Report's
results are summarized below under Biological Review.
For the second step, we assessed threats affecting the species'
status. We did this by following guidance in the ESA that requires us
to determine whether any species is endangered or threatened due to any
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 (sections 4(a)(1)(A) through (E)).
The BRT Report examined factors A, B, C, and E (Kobayashi et al.,
2011), and the Management Report examined factor D and conservation
efforts as per section 4(b) (NMFS, 2012). Results of the BRT and
Management Reports with regard to the five factors are summarized below
under Threats Evaluation.
For the third step, we completed an extinction risk analysis to
determine the status of the species. We asked the BRT to develop an
extinction risk analysis approach based on the best available
information for bumphead parrotfish. Extinction risk results in
Kobayashi et al. (2011) are based on factors A, B, C, and E of section
4(a)(1) of the ESA. Factor D (``inadequacy of existing regulatory
mechanisms''); Federal, state, and foreign conservation efforts were
assessed in the Management Report (NMFS, 2012), and not considered by
the BRT in its extinction risk analysis for the species. Thus, a final
extinction risk analysis was done by determining whether results of the
BRT's extinction risk analysis would be affected by conclusions made
based on the contents of the Management Report, thereby addressing the
five 4(a)(1) factors as well as conservation efforts that may mitigate
the impacts of threats to the species' status. The Policy for
Evaluation of Conservation Efforts When Making Listing Determinations,
or PECE policy (68 FR 15100; March 28, 2003) provides direction for the
consideration of protective efforts identified in conservation
agreements, conservation plans, management plans, or similar documents
(developed by Federal agencies, state and local governments, Tribal
governments, businesses, organizations, and individuals) that have not
yet been implemented, or have been implemented but have not yet
demonstrated effectiveness. The evaluation of the certainty of an
effort's effectiveness is made on the basis of whether the effort or
plan: establishes specific conservation objectives; identifies the
necessary steps to reduce threats or factors for decline; includes
quantifiable performance measures for
[[Page 66801]]
the monitoring of compliance and effectiveness; incorporates the
principles of adaptive management; and is likely to improve the
species' viability at the time of the listing determination. In
addition, recognition through Federal government or state listing
promotes public awareness and conservation actions by Federal, state,
tribal governments, foreign nations, private organizations, and
individuals.
For the fourth step, results of the biological review, threats
evaluation, and extinction risk analysis are considered to determine
whether the bumphead parrotfish qualifies for threatened or endangered
status. 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, 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 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 within the foreseeable future (threatened).
Thus, a species may be listed as threatened if it is likely to become
in danger of extinction throughout all or a significant portion of its
range within the foreseeable future.
Whether a species is ultimately protected as endangered or
threatened depends on the specific life history and ecology of the
species, the nature of threats, the species' response to those threats,
and population numbers and trends. In determining whether the species
meets the standard of endangered or threatened, we must consider each
of the threats identified, both individually and cumulatively. For
purposes of our analysis, the mere identification of factors that could
impact a species negatively is not sufficient to compel a finding that
ESA listing is appropriate. In considering those factors that might
constitute threats, we look beyond mere exposure of the species to the
factor to determine whether the species responds, either to a single
threat or multiple threats in combination, in a way that causes actual
impacts at the species level. In making this finding, we have
considered and evaluated the best available scientific and commercial
information, including information received in response to our 90-day
finding.
Biological Review
This section provides a summary of the BRT Report (Kobayashi et
al., 2011). The BRT first reviewed the ten public comments received on
the 90-day Finding and found that six of them reiterated other
materials available to the BRT. Two comments argued for the existence
of bumphead parrotfish DPSs in American Samoa and Guam, but no
supporting biological information was provided. A DPS is evaluated for
listing under the three following elements: (1) Discreteness of the
population segment in relation to the remainder of the species to which
it belongs; (2) The significance of the population segment to the
species to which it belongs; and (3) The population segment's
conservation status in relation to the Act's standards for listing
(i.e., is the population segment, when treated as if it were a species,
endangered or threatened?) (61 FR 4722: February 7, 1996). The BRT
found insufficient information to conclude that a DPS designation was
warranted for bumphead parrotfish. These two comments did, however,
provide information substantiating information already available to the
BRT regarding the role of fishing in the decline of bumphead parrotfish
around heavily populated and/or visited areas.
The two remaining comments contained information pertinent to
existing regulatory mechanisms throughout bumphead parrotfish range.
This information was provided to the staff compiling the management
report. Following are summaries of key biological information presented
in Kobayashi et al. (2011).
Species Description
The bumphead parrotfish is a member of a conspicuous group of
shallow-water fishes (parrotfishes in the family Scaridae, order
Perciformes) that are closely associated with coral reefs (Bellwood,
1994; Randall et al., 1997). Currently, 90 species in 10 genera are
recognized in the parrotfish family (Bellwood, 1994; Parenti and
Randall, 2000). Parrotfishes are distinguished from other fishes based
on their unique dentition (dental plates derived from fusion of teeth),
loss of predorsal bones, lack of a true stomach, and extended length of
intestine (Randall, 2005).
The bumphead parrotfish is the largest member of the parrotfishes,
growing to at least 110 cm total length (TL) (Kobayashi et al., 2011)
and a maximum total length of 130 cm and weighing up to 46 kg
(Donaldson and Dulvy, 2004; Randall, 2005). Adults are primarily olive
to blue green or grey in color with the anterior region near the head
being yellow to pink in coloration (Randall, 2005). A prominent bulbous
bump on the forehead, from whence the genus name is derived, is also a
common feature observed in adults. The bump is sexually dimorphic, it
slopes caudal to beak in females but is nearly parallel with the beak
in males, and the entire bump is usually larger in males (Munoz et al.,
2012). Bumphead parrotfish have been observed to reach sexual maturity
at 55-65 cm TL for females and 47-55 cm TL for males (Hamilton et al.,
2007). Consequently, juvenile bumphead parrotfish are defined as any
fish less than about 50 cm TL. Juveniles are greenish brown in color
with two to three vertical rows of white spots along the flank
(Bellwood and Choat, 1989; Randall, 2005). Bumphead parrotfish are
distinguished from other parrotfish species by possessing two to four
median predorsal scales, three rows of cheek-scales, 16-17 pectoral-fin
rays, 16-18 gill rakers, and 12 precaudal vertebrae (Kobayashi et al.,
2011).
English common names include buffalo parrotfish, bumphead
parrotfish, double-headed parrotfish, giant humphead parrotfish, green
humphead parrotfish, and humphead parrotfish. Non-English common names
in the Pacific include: Lendeke, Kitkita, Topa, Topa kakara, Perroquet
bossu vert, Togoba, Uloto'i, Gala Uloto'i, Laea Uloto'i, Loro cototo
verde, Berdebed, Kalia, Kemedukl, Kemeik, and Tanguisson. Several of
these names are a reflection of the different size ranges of the fish
used within a society (Adams and Dalzell, 1994; ASFIS, 2010; Aswani and
Hamilton, 2004; Hamilton, 2004; Hamilton et al., 2007; Helfman and
Randall, 1973; Johannes, 1981).
Currently, there is no population genetic information on bumphead
parrotfish. Regional variation in morphology, meristics, coloration, or
behavior has not been observed. Based on modeling of pelagic egg and
larvae transport, the species likely has an interconnected population
structure throughout its current range, with the possible exception of
both the eastern and western edges of the current range (Kobayashi et
al., 2011). While this conclusion is based on a single estimate of
larval duration, this estimate is the best available information and is
well within the range of values reported for labrids and scarids
(Ishihara and Tachihara, 2011). Several empirical studies did not find
a relationship between pelagic larval duration and genetic population
structure (Bay et al.,
[[Page 66802]]
2006; Bowen et al., 2006; Luiz et al., 2012) however they and others
(Saenz-Agudelo et al., 2012; Treml et al., 2012) all found evidence to
some degree of relatively long range dispersal in species with a
pelagic larval stage; as such, while pelagic larval duration is likely
one of many factors that influence reef fish dispersal and
connectivity, the existence of a pelagic larval life stage is likely to
result in interconnected population structure to some degree. More
recent work by Faurby and Barber (2012) asserts that pelagic larval
duration may be a much stronger determinant of realized larval
dispersal than suggested in empirical studies due to variation and
uncertainty associated with calculating genetic structure. Without
genetic information for bumphead parrotfish, it is impossible to
confirm or deny this relationship. Additionally, Treml et al. (2012)
found that broad-scale connectivity is strongly influenced by
reproductive output and the length of pelagic larval duration across
three coral reef species.
One year of current data (2009) was chosen for use in the pelagic
transport simulation; although some interannual variability exists in
ocean currents, PIFSC data available at Oceanwatch (http://oceanwatch.pifsc.noaa.gov/equator_eof.html) indicate that 2009
transitioned between high and low sea surface height anomalies and was
not likely to be anomalous in any respect for the whole year
considered. Although the simulation did not necessarily account for
inter-annual variability of current data outside of 2009, its reliance
on the entire year's current data, rather than a time-limited snapshot,
increases our confidence in its projections. Sponaugle et al. (2012)
provide a demonstration of significant agreement between modeled and
observed settlement of a coral reef fish. The BRT found, and we agree,
that the bumphead parrotfish is a single, well-described species that
cannot be sub-divided into DPSs based on the currently available
biological information (Kobayashi et al., 2011). In addition to the
criteria identified supra, DPSs may be 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. Because this determination involves consideration of factors
outside the technical and scientific expertise of the BRT, they were
not charged with determining whether distinguishing DPSs based on
international political boundaries is appropriate. This aspect of DPS
designation is discussed further below in the Listing Determination.
Habitat and Distribution
Adult bumphead parrotfish are found primarily on shallow (1-15 m)
barrier and fringing reefs during the day and rest in caves and shallow
sandy lagoon habitats at night (Donaldson and Dulvy, 2004). Extensive
reef structures on the Great Barrier Reef off the east coast of
Australia with adjacent lagoons appear to provide an example of optimal
habitat for bumphead parrotfish (Choat, personal communication). Lihou
and Herald are two isolated islands in the Coral Sea approximately 1000
km from the Great Barrier Reef with little fishing pressure. Densities
of bumphead parrotfish are over an order of magnitude higher on the
Great Barrier Reef compared with these two island locations (see Figure
3 in Kobayashi et al., 2011adapted from Choat, unpublished data). Thus,
differences in abundance between locations may be related, at least in
part, to habitat and biogeographic preferences (Kobayashi et al.,
2011). This highlights the importance of exposed outer reef fronts with
high structural complexity along a continuous reef system with adjacent
lagoons as preferred habitat. Likely limiting factors for bumphead
parrotfish abundance are sheltered lagoons for recruitment, high energy
forereef foraging habitat for adults, and nighttime shelter (caves) for
sleeping (Kobayashi et al., 2011).
Based on limited information, juvenile bumphead parrotfish habitat
is thought to consist mainly of mangrove swamps, seagrass beds, coral
reef lagoons, and other benthic habitats that provide abundant cover
(Kobayashi et al., 2011). Juvenile bumphead parrotfish in the Solomon
Islands were restricted to the shallow inner lagoon while larger
individuals of adult size classes (>60 cm TL) occurred predominately in
passes and outer reef areas (Aswani and Hamilton, 2004; Hamilton,
2004). Densities of juveniles (< 50 mm Fork Length (FL)) were an order
of magnitude higher in the inner lagoon around Cocos-Keeling in the
Indian Ocean than in the central lagoon; lower numbers of juveniles
occurred on the forereef. Size distributions of bumphead parrotfish at
Cocos-Keeling show a dominance of small individuals in the inner lagoon
with the mode at 18 mm FL. The mid-lagoon shows a bimodal distribution
with a mode of 24 mm FL and another mode at 72 mm FL. The forereef size
distribution consists of larger juveniles with a mode at 66 mm FL
(Choat, unpublished data).
Bumphead parrotfish are found in 45 countries in the Indo-Pacific
as well as disputed areas in the South China Sea. The BRT divided this
range into 63 strata, which are primarily country specific, but include
subsections or regions within countries in some cases. Certain
geographic strata are in or near the overall range polygon, but are not
known to have bumphead parrotfish (e.g., Hawaii, Johnston Atoll, Cook
Islands, Tokelau, Nauru, British Indian Ocean Territory, etc.).
Although data are limited, we found no evidence to conclude that
historical range was significantly different from current range. We
therefore conclude that the historical and current ranges are
equivalent (Kobayashi et al., 2011). Surveys conducted in northern
Tanzania and Bolinao, Philippines both reported no bumphead parrotfish
observed, however they were conducted at only a few sites within each
country and absence is likely based on limited survey data (see below).
McClanahan et al. (1999) specifically note that in reef surveys in
Tanzania, there was no evidence for species losses.
Abundance and Density
The bumphead parrotfish is thought to have been abundant throughout
its range historically (Dulvy and Polunin, 2004). Numerous reports
suggest that fisheries exploitation has reduced local densities to a
small fraction of their historical values in populated or fished areas
(Bellwood et al., 2003; Dulvy and Polunin, 2004; Hamilton, 2004; Hoey
and Bellwood, 2008). Estimates of abundance throughout the entire
geographic range of bumphead parrotfish are unavailable. However,
efforts have been made to document the abundance of reef fishes,
including bumphead parrotfish, at specific locations (Jennings and
Polunin, 1995; 1996; Dulvy and Polunin, 2004). Among the non-U.S. sites
examined in these studies, Australia's Great Barrier Reef had the
highest observed densities of bumphead parrotfish with an estimate of
3.05 fish per km\2\, followed by the Solomon Islands (1.40 fish per
km\2\), and Fiji (0.03 fish per km\2\). Reef fish surveys from northern
Tanzania and Bolinao in the Philippines did not record any bumphead
parrotfish, although it should be noted that in comparison to other
locations for which data are presented, these two studies represent the
lowest amount of survey effort (2 survey transects each) and the
highest levels of exploitation. Studies have also shown that larger
individuals of reef fish species began fleeing at great distances in
areas where human activity such as spearfishing occurs (e.g.,
[[Page 66803]]
Kulbicki 1998; Bozec et al. 2011), making them less detectable in
visual surveys, whereas in remote and/or protected areas, the large
individuals are relatively easily observed. Bozec et al.'s large fish
size begin at 30cm, only half of the average size of bumpheads;
however, their results indicate a general trend of the larger the fish,
the greater the fleeing distance. Their results also indicate that size
and shyness have combined effects on fishes' reaction to observers,
with large fish tending to be more shy. Where surveys focused on
species of commercial importance, the corresponding detection profiles
exhibited a marked diver avoidance since commercial species are usually
larger and more likely to be frightened by divers. Heavy subsistence,
artisanal, and commercial fisheries were reported at all locations
where bumphead parrotfish densities were less that 1 fish per km\2\.
Interpretation of these results is complicated by several additional
methodological concerns like limited depth range of surveys,
comparability of results from different survey methods, comparability
of results collected over a 13 year time span, and whether or not
surveys conducted can be considered representative of the entire
species range (Kobayashi et al., 2001). As such, while we have some
information on bumphead parrotfish abundance from a few areas within
the species range, the results should be interpreted and compared
cautiously.
Densities of bumphead parrotfish in the Indian Ocean show a
biogeographic density gradient with the highest densities adjacent to
the western Australian coast, and densities decreasing to the west
(Choat, unpublished data; see Figure 9 in Kobayashi et al. 2011).
Densities at Rowley Shoals off Western Australia are similar to high
densities observed on the outer Great Barrier Reef, and highlight the
importance of exposed outer reef habitats with adjacent lagoons and low
population density and utilization. Densities of bumphead parrotfish in
the western Indian Ocean (East Africa, Seychelles) are generally lower
than those observed in Australia and the western Pacific, although some
areas of the Seychelles such as Farquhar Atoll and Cousin Island
(Jennings, 1998) are exceptions to the gradient described above and
support large densities of bumphead parrotfish. Also, large numbers of
bumphead parrotfish are found in some areas of Borneo and Malaysia
(e.g., Sipadan; Kobayashi et al., 2011).
Surveys conducted by the Secretariat of the Pacific Community (SPC)
in their Pacific Regional Oceanic and Coastal Fisheries project in
2001-2008 revealed relatively high numbers of bumphead parrotfish in
Palau with slightly more than 1.5 individuals per station. Numbers in
New Caledonia were approximately half of those observed in Palau. Sites
in Papua New Guinea and the Federated States of Micronesia also
recorded modest numbers of individuals. Low numbers in Tonga, Fiji, and
the Solomon Islands may reflect fishing pressure (e.g., Dulvey and
Polunin, 2004; Hamilton, 2004), while their absence from a number of
locations is likely the result of the lack of suitable lagoon habitats
for recruitment (i.e., Niue, Nauru) (Kobayashi et al., 2011). Based on
SPC data, the maximum number of individuals per school was 120
individuals in Palau and 100 individuals in New Caledonia. Overall, the
average number of individuals observed per school was 8.17 fish
(Kobayashi et al., 2011).
In the U.S. Pacific Islands, abundance of bumphead parrotfish has
been assessed since 2000 as part of PIFSC's Reef Assessment and
Monitoring Program. Bumphead parrotfish were most abundant at Wake
Atoll in the Pacific Remote Island Areas (PRIAs) (~300 fish per km\2\),
followed by Palmyra Atoll in the PRIAs (5.22 fish per km\2\), Pagan
Island in the Commonwealth of the Northern Mariana Islands (1.62 fish
per km\2\), Jarvis Island in the PRIAs (1.26 fish per km\2\), Ta`u
Island in American Samoa (1.08 fish per km\2\), and Tutuila Island in
American Samoa (0.41 fish per km\2\; Kobayashi et al., 2011).
In summary, the abundance of bumphead parrotfish varies widely.
Sites where bumphead parrotfish are found in abundance (densities as
high as 300 fish per km\2\) include portions of the Great Barrier Reef
Marine Park (Bellwood et al., 2003), sites in the Seychelles, Wake
Atoll and Palmyra Atoll, U.S. Pacific Islands, Rowley Shoals Marine
Park, isolated regions of Papua New Guinea, portions of the Red Sea,
protected sites in Palau, and remote sites in the Solomon Islands
(Kobayashi et al., 2011). Alternatively, they are relatively uncommon
in parts of Fiji, Samoa, Guam, Mariana Islands, Tonga, and Solomon
Islands, with many other areas at intermediate levels of abundance.
Also, the BRT was unable to find abundance information in many parts of
the species' range (Kobayashi et al., 2011).
Contemporary Global Population Abundance
The BRT Report warns that ``There are inadequate data on bumphead
parrotfish population dynamics, demography, and temporal/spatial
variability to use even the most rudimentary of stock assessment
models. The data simply do not exist to allow one to credibly estimate
changes in population size, or even the magnitude of population size,
structured over space and time in a proper framework of metapopulation
dynamics and demographics'' for bumphead parrotfish. The BRT used the
best available information on population density from recent (1997-
2009) survey data to develop contemporary global estimates of adult
bumphead parrotfish abundance. Contemporary global population estimates
are based on the geographic range of bumphead parrotfish, amount of
suitable adult bumphead parrotfish habitat within its range, and the
density of adult bumphead parrotfish within the habitat. Population
density data were available for 49 of 63 of the strata from SPC and
ReefCheck underwater visual surveys. They then used a bootstrap
resampling simulation approach to estimate global population density by
randomly assigning from the actual density estimates one estimate to
each stratum in each simulation model iteration (Kobayashi et al.,
2011). Uncertainty and variability are incorporated by the use of 5000
iterations of the simulation.
The BRT used the bootstrap modeling approach to develop three
estimates of global abundance: (1) A ``regular-case'' estimate based on
the methods described above and resulting in a best estimate of 3.9
million adults (95 percent confidence interval = 69,000-61,000,000
adults); (2) a ``worst-case'' estimate which decreased the estimated
amount of available habitat and resulted in an abundance estimate of
2.2 million adults (95 percent confidence interval = 28,000-36,000,000
adults); and (3) a ``matched-case'' estimate where density estimates
for the 49 strata where surveys had occurred were based on those survey
data, and estimates for the other 13 strata were based on the
randomization process used in the ``regular-case'' estimate. This third
method resulted in an estimated abundance of 4.6 million adults (95
percent confidence interval = 17,000-67,000,000 adults). The BRT
concluded, and we agree, that the regular-case estimate provides the
most reliable estimate of current global abundance of bumphead
parrotfish. However, all models involved large confidence intervals,
and high uncertainty is associated with all three estimates.
Accordingly, all population estimates are to be interpreted with
caution.
[[Page 66804]]
Global Abundance Trends
Anecdotal accounts abound of past abundance and recent declines of
bumphead parrotfish in many parts of its range (see literature cited in
Kobayashi et al., 2011 and NMFS, 2012). Data on appropriate spatial and
temporal scales for both historical and contemporary abundances are
needed to quantify historic global abundance trends. As described
above, the BRT provided contemporary global abundance estimates.
However, they found available historical data on such small spatial
(e.g., Palau fisheries data, 1976-1990) and temporal (e.g., underwater
visual data, 1997-present) scales that historical global population
abundance cannot be quantitatively estimated with any reasonable
confidence. In the absence of historical quantitative data, the BRT
developed two estimates of historical global abundance of adult
bumphead parrotfish based on the available contemporary survey data and
assumptions regarding likely historic levels of density and that the
amount of available habitat was the same as currently. One estimate,
called the ``virgin-case'', is based on the assumption that historical
density is reflected by the density of bumphead parrotfish in the
transects surveys that had bumphead parrotfish present (7 percent of
the 6,561 transects), while the other estimate, called ``historic-
density'', assumes that historical density was 3 fish per 1000 m\2\
which is derived from current densities in areas where bumphead
parrotfish are considered abundant. The virgin-case estimate of
historical abundance was 131.2 million adults (95 percent confidence
interval = 66.5-434 million adults), while the historic-density
estimate was 51 million (the BRT did not calculate estimates of
precision for this estimate).
The BRT states that ``the estimates of virgin abundance and related
inferences about degree of population reduction are highly speculative
and subject to a great deal of uncertainty'' (Kobayashi et al., 2011,
p. 50). Uncertainty results from possible bias in assumed historical
densities, lack of historical density data to validate the methodology
on any spatial scale, the amount of habitat available historically may
have been over- or under-estimated, historical ecological changes
(e.g., reduction in bumphead parrotfish predators) reduce reliability,
and density-dependant mechanisms may have affected bumphead parrotfish
populations differently in historical times than in contemporary times
(Kobayashi et al., 2011; NMFS, 2011). However, the BRT's modeling
results are the best available information on historical and current
bumphead parrotfish population abundances. In the ``Status of Species''
conclusion, the BRT states that the global bumphead parrotfish
population shows ``evidence of a large overall decline and continuing
trend of decline despite lack of strong spatial coherence'' (Kobayashi
et al., 2011, p. 54). Based on the BRT's population modeling results
and the uncertainty associated with them, we conclude that adult
bumphead parrotfish have undergone a decline in historical population
abundance but we are unable to quantify, with any degree of accuracy,
the magnitude of that decline.
Future Abundance
In order to quantitatively predict likely future global abundance
trends for adult bumphead parrotfish, spatially-explicit data on
current and projected levels of the various threats to bumphead
parrotfish for each strata would need to be incorporated into a
population model because these threats are variable throughout the
species range (e.g., some strata are unfished, some strata are heavily
fished, some strata may be trending independently of human impact).
These data are not currently available so we cannot reliably quantify
how trends in current and future human activities and other threats
will impact the population into the future. The BRT was not able to
estimate future population trends by strata, and accordingly, did not
attempt a future projection. As such, we conclude that future global
population trends for adult bumphead parrotfish are unquantifiable at
this time. However, based on the information provided in the BRT Report
(Kobayashi et al., 2011), we conclude that, qualitatively, the
available evidence suggests a continuing trend of decline in the global
abundance of bumphead parrotfish is likely to continue into the future.
Age and Growth
The bumphead parrotfish appears to have a reasonably well-
characterized growth curve and approaches its maximum size at
approximately 10-20 years of age with a longevity estimated at
approximately 40 years. Most individuals seen in adult habitat are
likely older than approximately 5 years (Kobayashi et al., 2011). These
estimates have been developed for bumphead parrotfish based on several
studies from northeast Australia (Choat and Robertson, 2002), the
western Solomon Islands (Hamilton, 2004), New Caledonia (Couture and
Chauvet, 1994), and the Indo-Pacific region (Brothers and Thresher,
1985). Choat and Robertson (2002) estimated maximum age for bumphead
parrotfish to be 40 years of age assuming that checks on otoliths are
deposited annually, although others have estimated maximum age to range
from the upper 20s to mid 30s (Hamilton, 2004). All of these estimates
may be overly conservative as the largest and potentially oldest
individuals observed may not have been included in the analysis (Choat
and Robertson, 2002; Hamilton, 2004). In New Caledonia, Couture and
Chauvet (1994) determined that bumphead parrotfish have a slow growth
rate and in their sampling, the oldest individual was estimated at 16
years. With the exception of the study from New Caledonia, which used
scale annuli increments, all ages were determined using otolith
sections; some concern has been expressed that these two age
determination methods are not equally valid. Based on limited sample
size, lack of validation and/or disagreement between scale and otolith
techniques, the potential exists to misestimate longevity, growth, and
natural mortality for the species (Choat et al., 2006).
Data collected in the western Solomon Islands suggest differential
growth between sexes for bumphead parrotfish. Studies indicate that
males attain a larger asymptotic size than females and growth is slow
but continuous throughout life. In contrast, females exhibit more
determinate growth characteristics with asymptotic size established at
around age 15 years (Hamilton, 2004).
Age and growth characteristics of juvenile bumphead parrotfish are
less well known than those of adults. Pelagic larval duration was
estimated at 31 days using pre-transitional otolith increments from
just one specimen (Brothers and Thresher, 1985).
The average size of individual bumphead parrotfish observed from
SPC surveys was 59.7 cm TL (SD = 20.8), with the largest individual
being 110 cm and the smallest being 14 cm. Notable size differences
were observed at different locations. These size differences could
reflect variable habitat-related growth conditions, recruitment
problems, or some level of population structure, but more likely
reflect differences in the intensity of harvest and the degree to which
size structure of populations has been truncated (Kobayashi et al.,
2011).
Feeding
Parrotfishes as a family are primarily considered herbivores. A
majority of
[[Page 66805]]
parrotfishes inhabiting areas around rocky substrates or coral reefs
use their fused beak-like jaws to feed on the benthic community. Based
on differences in morphology, parrotfishes are separated into two
distinct functional groups: scrapers and excavators (Bellwood and
Choat, 1990; Streelman et al., 2002). Scrapers feed by taking numerous
bites, removing material from the surface of the substratum, while
excavators take fewer bites using their powerful jaws to remove large
portions of both the substrate and the attached material with each
bite. As a result of even moderate levels of foraging, both scrapers
and excavators can have profound impacts on the benthic community.
Thus, it is widely recognized that parrotfishes play important
functional roles as herbivores and bioeroders in reef habitats
(Bellwood et al., 2003; Hoey and Bellwood, 2008).
Bumphead parrotfish are classified as excavators feeding on a
variety of benthic organisms including corals, epilithic algae,
sponges, and other microinvertebrates (Bellwood et al., 2003; Calcinai
et al., 2005; Randall, 2005; Hoey and Bellwood, 2008). A foraging
bumphead parrotfish often leaves distinct deep scars where benthic
organisms and substrate have been removed. As such, their contribution
as a major bioeroder is significant. A single individual is estimated
to ingest more than 5 tons (27.9 kg per m\2\) of reef carbonate each
year (Bellwood et al., 2003); hence, even small numbers of bumphead
parrotfish can have a large impact on the coral reef ecosystem.
Bumphead parrotfish show little evidence of feeding selectivity;
however, a significant portion (up to 50 percent) of their diet
consists of live coral (Bellwood and Choat, 1990; Bellwood et al.,
2003; Hoey and Bellwood, 2008). On the Great Barrier Reef, bumphead
parrotfish are considered major coral predators. One study documented
removal of up to 13.5 kg per m\2\ of live coral per year, but also that
slightly more foraging activity was directed towards algae than living
coral (Bellwood et al., 2003). Thus, adult bumphead parrotfish are not
obligate corallivores but rather generalist benthic feeders. Juvenile
bumphead parrotfish diet is not well documented but likely also
includes a broad spectrum of softer benthic organisms. Live coral may
be relatively unimportant due to the lack of high densities of corals
in some juvenile habitats. Generally, bumphead parrotfish appear to be
opportunistic foragers and would likely cope with ecosystem shifts in
the coral reef community, based upon their behavior and ecology. For
example, shifts in benthic species composition (changes in the
breakdown of hard corals, soft corals, coralline algae, fleshy algae,
sponges, bryozoans, tunicates, etc.) would likely not adversely affect
bumphead parrotfish given their nonselective diet (Kobayashi et al.,
2011).
Movements and Dispersal
Adult bumphead parrotfish movement patterns are distinct between
day and night. Diurnal movement patterns are characterized by groups of
individuals foraging among forereef, reef flat, reef pass, and clear
outer lagoon habitats at depths of 1-30 m (Donaldson and Dulvy, 2004).
The bumphead parrotfish is a gregarious species that can be observed
foraging during the day in schools of 20 to more than 100 individuals
(Gladstone, 1986; Bellwood et al., 2003). Groups of foraging parrotfish
are highly mobile and often travel distances of several kilometers
throughout the day. For example, a study of adult bumphead parrotfish
movements and home ranges in the Solomon Islands demonstrated that
adults range up to 6 km (3.7 mi) daily from nocturnal resting sites
(Hamilton, 2004). At dusk, schools of parrotfish move to nocturnal
resting sites found among sheltered forereef and lagoon habitats.
Bumphead parrotfish remain motionless while resting, and use caves,
passages, and other protected habitat features as refuges during the
night. Although bumphead parrotfish travel considerable distances while
foraging, they show resting site fidelity and consistently return to
specific resting sites (Aswani and Hamilton, 2004).
Dispersal of bumphead parrotfish occurs primarily by passive
dispersal of pelagic fertilized eggs and larvae. Many details of the
early life history of the species are unknown. In other parrotfishes,
eggs are pelagic, small, and spindle shaped (1.5-3 mm long and 0.5-1 mm
wide; Leis and Rennis, 1983). Time to hatching is unknown, but is
likely between 20 hours and 3 days, as for other reef fishes observed
spawning on the shelf-edge (Colin and Clavijo, 1988). Bumphead
parrotfish pelagic ecology is unknown, but successful settlement
appears to be limited to shallow lagoon habitats characterized by low-
energy wave action and plant life (e.g., mangroves, seagrass, or
plumose algae) (Kobayashi et al., 2011). High relief coral heads (e.g.,
Turbinaria) in sheltered areas also seem to be suitable juvenile
habitat (Kobayashi et al., 2011). Mechanisms by which settling bumphead
parrotfish larvae find these locations are unknown, although recent
research on other species of coral reef fish larvae suggests that a
variety of potential cues could be used for active orientation (Leis,
2007).
Connectivity in bumphead parrotfish was examined by the BRT using a
computer simulation of larval transport (Kobayashi et al., 2011).
Surface currents at a resolution of 1 degree of latitude and longitude
were used with a simulated pelagic larval duration of 31 days (Brothers
and Thresher, 1985) with a settlement radius of 25 km. This settlement
radius estimate was used in previous simulation work (Kobayashi, 2006;
Rivera et al., 2011). If propagule survivorship is the main value being
estimated, settlement distance is important as well as swimming
orientation and other behaviors at the settlement stage. However, for
understanding geographic linkages (as in this application), settlement
distance is not a key driver of results. As discussed above, much of
the recent literature on the role of pelagic larval duration in
determining realized dispersal distances has resulted in mixed
conclusions. There is support that pelagic larval duration can be a
strong predictor of dispersal distances (Shanks et al., 2003) yet a
poor predictor of genetic similarity (Bay et al., 2006; Bowen et al.,
2006; Luiz et al., 2011; Weersing and Toonen, 2009). As discussed
previously, studies have shown that multiple factors add to the
complexity of understanding larval dispersal but they all provide
evidence of some level of exchange between sub-populations that are far
apart, relative to the range of the species in question. Treml et al.
(2012) in particular, found that broad-scale connectivity is strongly
influenced by reproductive output and the length of pelagic larval
duration. We are aware of no morphological, life history, or other
variation that would suggest population structuring. In the absence of
information on complicating factors for bumphead parrotfish, the BRT's
simulation of pelagic larval dispersal is the best available
information with regard to population connectivity for this species.
Single-generation and multi-generation connectivity probabilities
were tested. A number of sites appear to have significant potential as
stepping stones with a broad range of input and output strata
interconnected in a multi-generational context. Most sites with
significant seeding potential are located in close proximity to other
sites (e.g., east Africa, central Indo-Pacific). The BRT concluded that
bumphead parrotfish likely have an interconnected population structure
due to oceanographic transport of pelagic eggs
[[Page 66806]]
and larvae, with this effect being most pronounced near the center of
the species range, but with some degree of isolation in both the
eastern and western edges of the species range (Kobayashi et al.,
2011).
Reproductive Biology
Unlike most parrotfishes which are protogynous (sequential)
hermaphrodites, bumphead parrotfish appear to be gonochoristic
(unisexual). Females reach sexual maturity over a broad size range.
While they begin to reach sexual maturity at about 500 mm TL, 100
percent of females attain maturity by about 700 mm TL and age 11 yrs.
The size at which 50 percent of females have reached maturity is
estimated at 550-650 mm TL at age 7-9 yrs (Hamilton, 2004; Hamilton et
al., 2007). Males also reach maturity over a wide size range similar to
females, but males begin maturing at smaller sizes and younger ages
than females. For example, the smallest mature male observed in age and
growth studies was 470 mm TL and age 5 yrs., while the smallest mature
female was 490 mm TL and age 6 yrs (Hamilton, 2004; Hamilton et al.,
2007).
Spawning may occur in most months of the year. Hamilton et al.
(2007) found ripe males and females every month of an August through
July sampling period in the Solomon Islands. However, females with
hydrated ova, indicative of imminent spawning, were only found from
February to July. Spawning may have a lunar periodicity, with most
spawning occurring in the early morning around the full moon in reef
passage habitats (Gladstone, 1986). Hamilton et al. (2007) found
hydrated ova (Colin et al., 2003) in females captured from reef
passages and along the outer reef. Bumphead parrotfish are serial
spawners with undocumented but presumably very large batch fecundity,
considering the large body and gonad size coupled with small egg size
(Kobayashi et al., 2011).
Observations of spawning have involved a single male and female. In
other parrotfishes, Thresher (1984) describes the establishment of
temporary spawning territories by males, with females being courted by
males as they passed through spawning territories, and an assemblage of
individuals acting as a spawning school. Although Gladstone (1986)
described a simple mobile group of bumphead parrotfish individuals from
which pair spawning took place, others have described what appeared to
be a dominant male spawning with females and smaller sneaker males
attempting to participate in spawning. The putative dominant male
displayed bright green coloration during spawning. The evidence that
males grow to larger sizes than females (Hamilton, 2004) supports the
existence of a nonrandom mating system where a reproductive advantage
is conferred to larger dominant males (Ghiselin, 1969; Kobayashi et
al., 2011). Warner and Hoffman (1980) showed mating system and sexual
composition in two parrotfish relatives is density dependent. Munoz et
al. (2012) have documented male-male head-butting encounters that may
serve to establish mating territories or dominance and confirm the
presumed function of the larger bumps in males.
Settlement and Recruitment
As with many other aspects of bumphead parrotfish biology, little
is known about the processes following settlement of larvae in the
benthic environment. Juveniles appear to gradually work their way
towards adult habitats on the forereef areas, but timing and duration
of this movement are unknown. The smallest size at which bumpheads
enter the adult population on forereef areas is approximately 40 cm TL.
These large juveniles are not often seen in surveys and may remain
cryptic until adopting the wide-ranging swimming and foraging behavior
of adults. Certain areas, for example the Great Barrier Reef, do not
appear to receive significant recruitment (Bellwood and Choat, 2011).
Adults on the Great Barrier Reef are thought to originate from
elsewhere (north), which may explain the latitudinal trend of
decreasing abundance toward southern portions of the area (Kobayashi et
al., 2011).
Ecosystem Considerations
Despite typically low abundance, bumphead parrotfish can have a
disproportionately large impact on their ecosystem as a result of their
size and trophic role. Their role as non-selective, excavator feeders
is likely important for maintaining species diversity of corals and
other benthic organisms. For example, certain species of coral (i.e.,
plate-forming) and algae can quickly monopolize substrate if unchecked.
Non-selective feeding prevents any one organism from dominating the
benthic ecosystem. Hence the species may be a classic example of a
keystone species. The role of bumphead parrotfish in bioerosion and
sand generation is also of notable importance; this effect is clearly
seen by the persistence of dead coral skeletons in areas where
excavating herbivores have been reduced (Bellwood et al., 2004).
Carrying Capacity
There is no evidence regarding limiting factors for bumphead
parrotfish population growth, particularly under pristine conditions.
Some likely limiting factors for past, present, and/or future bumphead
parrotfish population growth include settlement and recruitment
limitation factors (Doherty, 1983; Sale, 2004), juvenile habitat, adult
sleeping habitat, requisite abundance of conspecifics for successful
group foraging or reproduction, and human harvest. Most of these
factors are likely to become more limiting over time (Kobayashi et al.,
2011).
Threats Evaluation
Threats Evaluation is the second step in the process of making an
ESA listing determination for bumphead parrotfish as described above in
``Listing Determinations Under the ESA''. This step follows guidance in
the ESA that requires us to determine whether any species is endangered
or threatened due to any 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 (sections 4(a)(1)(A) through
(E)).
The BRT Report assessed 14 specific threats according to factors A,
B, C, and E as follows: for factor (A), the BRT identified three
threats: adult habitat loss or degradation, juvenile habitat loss or
degradation, and pollution; for factor (B), the BRT assessed harvest or
harvest-related adult mortality, and capture or capture-related
juvenile mortality; for factor (C), the BRT identified five threats:
competition, disease, parasites, predation, and starvation; and for
factor (E), the BRT discussed four threats: global warming, ocean
acidification, low population effect, and recruitment limitation or
variability. The BRT determined the severity, scope, and certainty for
these threats at three points in time--historically (40-100 years ago
or as otherwise noted in the table), currently, and in the future (40-
100 years from now; Kobayashi et al., 2011). Each threat/time period
combination was ranked as high/medium/low severity with plus or minus
symbols appended to indicate values in the upper or lower ends of these
ranges, respectively.
Of the 14 threats, the BRT Report determined that five had
insufficient data to determine severity, scope, or
[[Page 66807]]
certainty at any of the three points in time (competition, disease,
parasites, starvation, and low population effect). We agree that
sufficient information is not available to determine the severity of
these threats. The remaining nine threats are described below by
factor.
Factor D threats (related to inadequacy of existing regulatory
mechanisms), were assessed in the Management Report (NMFS, 2012). Two
public comments received in response to the 90-Day Finding contained
information relevant to existing regulatory mechanisms that was
considered in the Management Report. One comment provided information
on cultural significance, harvest methods, and the importance of Marine
Protected Areas (MPAs) and remote areas with limited access that may
provide refuge for the species within a narrow portion of its range.
The second comment provided information pertaining to existing
regulatory mechanisms in some parts of the species range and the
effectiveness of MPAs in providing some benefit to the species. In the
Management Report, we summarized existing regulatory mechanisms in each
of the 46 areas where bumphead parrotfish occur, including fisheries
regulations and MPAs. Additionally, we developed a comprehensive
catalog of protected areas containing coral reef and mangrove habitat
within the range of the species (NMFS 2012, Appendix A-1 and A-2) and
evaluated how the MPA network addresses threats to the species (NMFS
2012, Sections 2.1.2.1-46 and 4). The Management Report authors did not
determine the severity, scope, and certainty for Factor D threats at
three points in time--historically, currently, and in the future--as
did the BRT. They compiled information on the presence of
international, national, and local scale regulations and then discussed
general themes and patterns that emerged in order to assess whether the
inadequacy of existing regulatory mechanisms is a factor that changes
the extinction risk analysis results provided by the BRT.
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range
Juvenile habitat loss or degradation was rated by the BRT as one of
the two (along with adult harvest) most severe threats to bumphead
parrotfish, rating its severity as ``medium'' historically and as
``high'' both currently and over a 40-100 year future time horizon. As
described by the BRT, shallow mangrove, seagrass, and coral reef lagoon
habitats are susceptible to pollution, modification, and increased
harvest pressure, among other anthropogenic pressures. The juvenile
habitat specificity of bumphead parrotfish highlights this phase of the
life history as highly vulnerable (Kobayashi et al., 2011).
In contrast to juvenile habitat, the BRT concluded that adult
habitat loss and/or degradation is not a high priority concern, rating
its severity as ``medium'' both currently and over a 40-100 year future
time horizon (with a historical rating of low). Drastic morphological
changes to coral reefs might impact bumphead parrotfish if high-energy
zones were reduced or wave energy was diffused or if nocturnal resting/
sleeping locations were no longer available (Kobayashi et al., 2011).
Both are quite possible under some scenarios for climate change where
coral reef structures can't keep up with sea level rise and also die or
experience decreased growth from increased temperature and then degrade
and fail to be replaced by similar three-dimensional structure that
creates both the high energy zones (reef crests) and sleeping
structures. Adult bumphead parrotfish appear to be opportunistic
foragers and would likely cope with ecosystem shifts in the coral reef
community, based on their behavior and ecology. For example, shifts in
benthic species composition (e.g., changes in the breakdown of hard
corals, and the relative abundance of soft corals, coralline algae,
fleshy algae, sponges, bryozoans, tunicates, etc.) would probably not
adversely affect bumphead parrotfish given their nonselective diet.
Some components of the coral reef ecosystem are likely more affected by
the presence or absence of bumphead parrotfish than bumpheads are
dependent on those ecosystem components.
The BRT concluded that pollution is not a high priority concern,
rating its severity as ``low'' both historically and currently, and
``medium -'' over a 40-100 year future time horizon. Pollution events
(e.g., oil spills) can be catastrophic to coral reef ecosystems.
However, such events remain episodic, rare, and are usually localized
in the context of a widely-distributed, mobile species. Habitat
modification as a result of pollution is most likely to be an issue
with juvenile habitat since it is more exposed to anthropogenic impacts
because of proximity, shallowness, and tendency to be more contained
(e.g., lagoons, as opposed to open coastal waters). The BRT Report
expressed high concern about the effects of pollution on the quantity
and quality of juvenile habitat, but expressed less concern about adult
habitat since adult habitat is larger, spans a wider geographic range,
and is typically a more open environment (Kobayashi et al., 2011).
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The BRT rated harvest of adults as one of the two most severe
threats (along with juvenile habitat loss) to bumphead parrotfish, with
severity rated as ``high'' historically, currently, and over a 40-100
year future time horizon. In contrast to adult harvest, the BRT
concluded that juvenile harvest is less of a concern, rating its
severity as ``medium'', both currently and over a 40-100 year future
time horizon (rated as ``nil'' historically). While the BRT rated the
threat of harvest differently by life stage, we first discuss general
harvesting issues applicable to both life stages, then consider
specific justifications for the different rankings.
Bumphead parrotfish are highly prized throughout their range. In
addition to their commercial value, bumphead parrotfish are culturally
significant for many coastal communities and used in feasts for
specialized ceremonial rites (Severance, pers. comm.; Riesenberg,
1968). As such, fisheries for this species have been in place since
human inhabitation of these coastal regions (Johannes, 1978; 1981).
Following are descriptions of life history characteristics of the
species that affect vulnerability to harvest, harvest gears and
methods, and summaries of harvest data from the few locales where
available.
Life History Characteristics Relevant to Harvest
Immature bumphead parrotfish (40-50 cm TL, sub-adults) recruit to
adult habitat (coral reef forereefs); thus, the following descriptions
of life history characteristics and methods/gears relate to sub-adults
and adults. Several life history characteristics increase the
vulnerability of sub-adult and adult bumphead parrotfish to harvest
such as nocturnal resting behavior, diurnal feeding behavior, large
size and conspicuous coloration. At night, bumphead parrotfish
frequently remain motionless while resting in refuge sites and they
consistently return to specific resting sites. Unlike other parrotfish
species, bumphead parrotfish do not excrete a mucus cocoon to rest
within. Thus, resting in shallow water in large groups and returning to
the same unprotected resting sites all increase vulnerability of adult
bumphead parrotfish to harvest at night (NMFS, 2012). Adult bumphead
parrotfish schools effectively announce their
[[Page 66808]]
presence by loud crunching noises associated with feeding activity,
which can be heard at least several hundred meters away underwater. In
addition, bumphead parrotfish may form spawning aggregations during the
daytime. Thus, foraging in shallow water in schools, conspicuous
foraging noise, and spawning behavior also all increase the
vulnerability of adult bumphead parrotfish to harvest (NMFS, 2012).
It is likely that juvenile bumphead parrotfish are more vulnerable
to harvest in populated regions based on their aggregating behavior and
tendency to inhabit shallow lagoon environments. They suffer the same
vulnerability from night time harvest as adults and sub-adults as they
also use traditional nocturnal resting refuge sites.
Harvest Methods and Gears
Historically, fishing for bumpheads typically took place at night
while fish were motionless in their nocturnal resting sites. Fishermen
armed with hand spears would paddle wooden canoes or simply walk across
shallow reef habitats using a torch assembled from dried coconut fronds
in search of resting fish (Dulvy and Polunin, 2004). With the advent of
dive lights, SCUBA, freezers, and more sophisticated spears and spear
guns, the ability to exploit bumphead parrotfish has increased
dramatically over the last several decades (Hamilton, 2003; Aswani and
Hamilton, 2004).
Current Indo-Pacific coral reef fisheries are nearly as diverse as
the species they target, and include many subsistence, commercial, and
sport/recreational fisheries employing a vast array of traditional,
modern, and hybrid methods and gears (Newton et al., 2007; Wilkinson,
2008; Armada et al., 2009; Cinner et al., 2009; NMFS, 2012). This
tremendous increase in fisheries using both selective and non-selective
gears is a significant factor in the high severity of threat to adult
bumphead parrotfish. In addition, even though many destructive gears
and methods are illegal in most countries with coral reef habitat
within their jurisdiction, they are still used within the range of
bumphead parrotfish. Examples include blast fishing using explosives to
kill or stun fish, and the use of poisons like bleach or cyanide. Blast
fishing is very damaging to coral reef habitat and can result in
significant time required for recovery (Fox and Caldwell, 2006).
Summary of Harvest Data
Data pertaining to harvest are sparse, incomplete, or lacking for a
majority of regions across the range of bumphead parrotfish, though
efforts have been made over the past 30 years to obtain fisheries
harvest information at a few sites in the central and western Pacific.
However, most of the available harvest data combine all parrotfish
species into one category, making it difficult to identify bumphead
parrotfish harvest amounts. Harvest data specific to bumphead
parrotfish exist for Palau (Kitalong and Dalzell, 1994), Guam (NOAA,
The Western Pacific Fisheries Information Network), Solomon Islands
(Aswani and Hamilton, 2004; Hamilton, 2003), Fiji (Dulvy and Polunin,
2004), and Papua New Guinea (Wright and Richards, 1985).
In Palau, efforts to assess commercial landings of reef fishes were
made from 1976 to 1990 (Kitalong and Dalzell, 1994). All harvest data
were collected at the main commercial landing site and it is estimated
that these data accounted for 50-70 percent of the total commercial
catch. Overall, bumphead parrotfish represented 10 percent of reef
fisheries landings in Palau, making it the second most important
commercial reef fish. It was estimated that an average of 13 metric
tons of bumphead parrotfish were sold annually during the study. The
highest landings were recorded in the mid-1980s, with a maximum of 34
metric tons sold in 1984. Declines in total catch were observed
following the mid-1980s, creating concern over the conservation status
of bumphead parrotfish stocks. As a result, restrictions were put on
the harvest of bumphead parrotfish in 1998 and it is now illegal to
export, harvest, buy or sell with the intent to export bumphead
parrotfish of any size in the waters of Palau.
Harvest data for Guam from creel surveys and commercial purchase
records were obtained from the NOAA Western Pacific Fisheries
Information Network. Creel survey data were collected from 1982 to
2009. Based on the results of the creel surveys, a total of 10 bumphead
parrotfish (0.12 metric tons) were harvested in Guam during the survey
period. No landings have been reported since 2001 from creel surveys.
Data pertaining to commercial sales of parrotfish are provided for
individual sales and, it is assumed, correspond to the same time
period. As such, commercial sale data estimated a harvest of 9 fish or
0.45 metric tons from 1982 to 2009.
Solomon Islands (New Georgia Group) creel survey harvest data were
obtained from August 2000 and July 2001 (Hamilton, 2003; Aswani and
Hamilton, 2004). Bumphead parrotfish accounted for 60 percent of reef
fish catch in Roviana lagoon (Kalikoqu). Total harvest of bumphead
parrotfish was 0.63 metric tons. Fish caught ranged from 28.5 to 102.0
cm TL with a mean size of 62.7 cm TL; very few individuals were larger
than 100 cm TL. There is currently a ban on harvest of any species
while using SCUBA; however, there are no restrictions on the harvest of
bumphead parrotfish using other extraction methods (FAO, 2006).
Harvest data for Fiji are based on the results of a fisheries
development program at Kia Island carried out by the Fiji Department of
Agriculture in 1970 and from the 1990 Fiji Fisheries Division Annual
Report (Adams, 1969; Richards et al., 1993). During the period of the
fisheries development program, bumphead parrotfish accounted for 70
percent of the total reef fisheries catch and yielded 22.3 metric tons.
In 1990 bumphead parrotfish accounted for 5 percent of total commercial
landings and yielded 230 metric tons (Dulvy and Polunin, 2004).
In Papua New Guinea, harvest data were obtained from an assessment
of a small-scale artisanal fishery conducted in the Tigak Islands
(Wright and Richards, 1985). Harvest data were collected from the only
commercial site for selling fish in Kavieng, New Ireland. A total of
636 bumphead parrotfish were collected during the survey period (13
months starting in November 1980) and represented 5 percent of total
fisheries catch. The mean size of fish harvested was 57 cm TL.
Data pertaining to harvest of juvenile bumphead parrotfish are
sparse. The BRT rated the severity of the threat of juvenile harvest as
``medium'' both currently and in the future because they define a
``medium'' level of certainty as having ``some published and
unpublished data to support the conclusion this threat is likely to
affect the species with the severity and geographic scope ascribed''.
In other words, they felt that harvest is a legitimate threat for all
size classes, however there is more evidence to support the conclusion
that adult harvest is a high severity threat to the species both
currently and in the future, as opposed to the lack of information
available to make the same conclusion about juvenile harvest.
Bumphead parrotfish can be found in great local abundance at sites
isolated from population centers or protected from exploitation (Dulvy
and Polunin, 2004). Observations at remote sites, with minimal to no
harvest, are not restricted to one specific geographic region but span
across the geographic range of bumphead parrotfish. Sites with high
human population densities and associated fisheries exploitation have
[[Page 66809]]
lower densities of bumphead parrotfish compared to remote and
uninhabited locations (Kitalong and Dalzell, 1994; Dulvy and Sadovy,
2003; Donaldson and Dulvy, 2004; Chan et al., 2007; Hoey and Bellwood,
2008). Although fisheries harvest data are sparse, the implication is
that lower densities of bumphead parrotfish in more heavily populated
areas may be due to fishing and other human activities. Munoz et al.
(2012) provide the first scientific documentation of aggressive
headbutting behavior between male bumphead parrotfish. They propose
that this dramatic aspect of the species' social and reproductive
behavior has gone unnoticed until now for one of two reasons: because
low population densities resulting from overfishing reduce competition
for resources, or because headbutting contests are common, but negative
responses to humans in exploited populations preclude observations of
natural behavior. However, this behavior has not been reported in many
other well-studied areas with densities approaching or exceeding that
of this study site, so there is not enough information to conclude in
what ways this behavior may be related to population density, if any.
Harvest Conclusion
Given their vulnerability based on life history characteristics and
the sparse data on harvest, the BRT concluded that the severity of
threat from harvest was medium for juveniles and high for adults.
C. Disease and Predation
There is very little information on the impacts of competition,
disease, parasites, and predation on bumphead parrotfish. The BRT only
had enough information to rate the threat of predation, rating its
severity as ``low'' historically and ``low--'' both currently and over
a 40-100 year future time horizon. The lack of habitat specificity or
diet specificity by this species would likely reduce the role of
competitive processes. An exception might be competition for adult
sleeping habitat if other large organisms (sharks, wrasses, other
parrotfishes, etc.) are vying for the same nighttime shelters.
Occasional predation by sharks has been discussed in several parts of
this report, but this is not thought to be important for bumphead
parrotfish population dynamics. There is insufficient information to
conclude that any of these issues will play a significant role
individually or cumulatively in the short- or long-term outlook for
bumphead parrotfish populations. There is not much known about egg/
larval and juvenile biology, but it is likely that predation on these
earlier phases of the life-history may be a more significant issue than
for adults.
D. Inadequacy of Existing Regulatory Mechanisms
Of the nine threats that the BRT was able to assess, regulatory
mechanisms have limited relevance to one of them (recruitment
limitation or variability under Factor E below), because regulation
cannot directly control this threat or its root cause. However,
regulatory mechanisms are relevant to the other threats. For the
purposes of evaluating Factor D, these eight threats are grouped and
referred to as follows: Habitat (juvenile habitat loss/degradation,
adult habitat loss/degradation, pollution); Harvest (adult harvest,
juvenile harvest, predation (harvest regulation of potential bumphead
parrotfish predators)); and Climate Change (global warming, ocean
acidification). Habitat Loss/Degradation and Harvest threats are
regulated much differently than Climate Change threats, and thus
regulatory mechanisms for these are assessed and discussed separately.
Assessment of Existing Regulatory Mechanisms Relevant to Habitat and
Harvest Threats
This section summarizes the assessment of regulatory mechanisms for
Habitat Loss/Degradation and Harvest threats from the Management Report
(NMFS, 2012).
Because habitat and harvest threats are generally due to localized
human activities, and therefore controllable by regulatory mechanisms
at the national or local levels, relevant regulatory mechanisms (laws,
decrees, regulations, etc., for the management of fisheries, coastal
habitats, and protected areas) were assessed for the 45 countries (and
disputed areas) within the range of bumphead parrotfish. These
mechanisms were grouped into two categories: (1) Regulatory mechanisms
for fisheries and coastal management; and (2) Additional regulations
within MPAs and other relevant protected areas (e.g., mangroves).
Generally, the first category encompasses a broad array of laws and
decrees across many jurisdictional scales from national to local,
whereas the second level consists of additional regulations that may
apply within MPAs/protected areas within each jurisdiction (NMFS,
2012).
Although adult harvest is better documented than juvenile harvest,
many of the gear types discussed previously may be used to harvest both
adults and large juveniles. As such, regulatory mechanisms for harvest
methods are not separated into methods specific to adult harvest and
juvenile harvest, unless specifically noted. Thus, all types of
fisheries regulations that may apply to bumphead parrotfish were
researched and compiled both inside and outside protected areas, with
particular emphasis on spearfishing, the primary gear type for directed
fishing (NMFS, 2012).
Loss and degradation of juvenile habitat may be caused by a wide
variety of activities because juveniles inhabit mangrove swamps,
seagrass beds, coral reef lagoons, and likely other coastal habitats.
Although adults typically occur in coral reefs, many of the impacts
that exist for juvenile habitat also apply in adult habitat areas.
Regulations related to the two primary habitats used by the species,
mangrove swamps and coral reefs, were also researched and compiled both
inside and outside of protected areas. Pollution as a threat is
relevant to habitat loss and degradation for both juveniles and adults
and is assessed within existing regulations for specific habitat types.
Because seagrass beds are found in or near mangroves and coral reefs,
they are not considered separately (NMFS, 2012).
Overall Patterns and Summary for Existing Regulatory Mechanisms
Several overall patterns emerged from the compilation and
evaluation of existing regulatory mechanisms addressing Harvest and
Habitat Loss/Degradation threats to bumphead parrotfish.
A wide array of regulatory mechanisms exists within the 46 areas in
bumphead parrotfish range that are intended to address the threats of
habitat loss/degradation and harvest for the species. Australia, Fiji,
Maldives, Micronesia, Palau, and Samoa all have fisheries regulations
pertaining specifically to parrotfish species, in some cases
specifically bumphead parrotfish. These range from prohibition of take
for all parrotfish, to size and bag limits, to seasonal restrictions,
to listing as an Endangered Species (Fiji). These six countries
together represent 26 percent of total coral reef habitat and 13.1
percent of mangrove habitat in the 46 areas within bumphead parrotfish
range.
Twenty-four out of the 46 areas have some sort of regulations
pertaining to spearfishing. These include prohibiting spearfishing
altogether, prohibiting fishing with SCUBA, prohibiting fishing with
lights (limiting night spearfishing), area closures, permit
requirements, or various combinations of those. Some
[[Page 66810]]
regulations may only apply in some areas within a country or
jurisdiction and some only within marine protected areas (MPAs). Those
24 areas combined represent 63.6 percent of total coral reef habitat
within the 46 areas in bumphead parrotfish range, although in some
cases regulations do not apply throughout the entire area of coral reef
habitat.
A different set of 24 out of the 46 areas within the species range
have some sort of regulatory mechanisms in place that offer some
protection to mangrove habitat. These regulations include prohibition
on mangrove harvest and/or sale, inclusion of mangroves in protected
areas, and sustainable harvest and/or restoration requirements.
Combined, these 24 areas account for 94.8 percent of mangrove habitat
in the 46 areas within the range of bumphead parrotfish.
Spearfishing regulations exist in a majority (17 out of 24) of the
areas within the area defined by the BRT as the significant portion of
the species range (SPOIR). Regulations providing some level of
protection for mangrove habitat exist in an even larger majority (19
out of 24) of areas within SPOIR.
Customary governance and management remain important in many areas
throughout bumphead parrotfish range and may confer conservation
benefits to the species. After intensive efforts by governments in the
past to centrally manage coastal fisheries, there has been a shift in
government policies from a centralized or ``top-down'' approach to
restore resources to a ``bottom-up'' or community-based approach. This
community-based management approach is more widespread in Oceania today
than any other tropical region in the world (Johannes, 2002). We found
documentation that at least 16 of the 46 areas within bumphead
parrotfish range employ traditional governance systems based on
customary and traditional resource management practices throughout all
or part of the country, most of which are explicitly recognized and
supported by their national governments. Notably, the national
government in Indonesia recognizes that customary law and/or
traditional management is adapted to local areas and therefore more
effective than a homogeneous national law. As such, coral reef
fisheries management is decentralized and delegated to the 503
Districts where District laws and regulations are based on customary
law and/or traditional management. Indonesia accounts for 40 percent of
mangrove habitat and 18.5 percent of coral reef habitat in the 46 areas
within bumphead parrotfish range. Fenner (2012) asserts that customary
marine tenure, or traditional resource management by indigenous
cultures, has high social acceptance and compliance and may work fairly
well for fisheries management and conservation where it is still
strong.
Marine protected areas simplify management and reduce enforcement
costs for fish populations where little biological information is
available (Bohnsack, 1998), which makes them an attractive and viable
option for reef fishery management and conservation, especially in
developing countries (Russ, 2002). There has been recent rapid growth
in coral reef and coastal MPAs. In 2000, there were 660 protected areas
world-wide that included coral reefs (Spalding et al., 2001). Mora et
al. (2006) compiled a database in 2006 with 908 MPAs covering 18.7
percent of the world's coral reefs. The Reefs at Risk Revisited report
(Burke et al., 2011) indicates that now 2,679 MPAs exist (a four-fold
increase in one decade),covering 27 percent of coral reefs worldwide,
over 1,800 of which occur within the range of bumphead parrotfish (NMFS
2012, Appendix A-1). An estimated 25 percent of coral reef area within
bumphead parrotfish range is within MPAs. Additionally, over 650
protected areas have been established throughout the range that include
mangrove habitat (Spalding et al., 2010; NMFS, 2012).
MPA is a broad term that can include a wide range of regulatory
structures. According to Mora et al. (2006), 5.3 percent of global
reefs were in extractive MPAs that allowed take, 12 percent were inside
multi-use MPAs that were defined as zoned areas including take and no-
take grounds, and 1.4 percent were in no-take MPAs, although this
information is now outdated. MPAs that occur within the range of the
bumphead parrotfish certainly represent different levels of protection
from no-take zones to limited restrictions on fishing and other
activities. There is evidence that no-take marine reserves can be
successful fisheries management tools and many have been shown to
increase fish populations relative to areas outside of the reserves or
the same area before the reserve was established (Mosquera et al.,
2000; Gell and Roberts, 2003). Mosquera et al. (2000) note in
particular that parrotfishes responded positively to protection, and
species with large body size and those that are the target of fisheries
(both of which describe bumphead parrotfish) respond particularly well.
It is noted, however, that a very small proportion of global MPAs are
no-take reserves that allow no fishing while the majority allow for
some level of extraction (IUCN, 2010). Within bumphead parrotfish
range, 20 percent of coral reef areas are in Australia, most of which
are within the Great Barrier Reef Marine Park (GBRMP); more than 33
percent of the GBRMP areas are known as ``green zones'' within which
fishing is entirely prohibited (GBRMPA, not dated). Additionally, Fiji
(3.1 percent of coral reef area in bumphead range) and the Maldives
(2.5 percent of coral reef in bumphead range) prohibit take of
parrotfish, so coral reef areas within those jurisdictions are
essentially no-take areas for bumpheads. When combined, a minimum
estimate of coral reef habitat that can be considered no-take within
bumphead parrotfish range is 12.2 percent (minimum because there may be
additional no-take marine reserves among the rest of the 1,874 MPAs
within bumphead range but Mora et al. (2006) were unable to
systematically identify and calculate those areas). Of note here is a
recently proposed network of MPAs including a large percentage of no-
take areas throughout Australia's EEZ, in addition to the GBRMP. Known
as the Commonwealth Marine Reserves Network, if finalized, this action
would greatly increase the area of marine protected zones and maintain
about \1/3\ of all marine protected areas as no-take zones throughout
the MPA network in Australia's EEZ (Commonwealth of Australia, 2012).
No-take marine reserves simplify management and reduce enforcement
costs for fish populations where little biological information is
available (Bohnsack, 1998) which makes them an attractive and viable
option for reef fishery management and conservation, especially in
developing countries (Russ, 2002).
On a global scale, Selig and Bruno (2010) found that MPAs can be a
useful tool for maintaining coral cover and that benefits resulting
from MPA establishment increase over time. The Reefs at Risk Revisited
report from 2011 offers effectiveness ratings for 30 percent of the
2,679 MPAs compiled therein. Within bumphead parrotfish range, 25
percent of total reef area within rated MPAs are in MPAs rated as
``effective'', defined as managed sufficiently well that local threats
are not undermining natural ecosystem function; 44 percent of reef area
within rated MPAs are in MPAs rated as ``partially effective'', defined
as managed such that local threats were significantly lower than
adjacent non-managed sites, but there still may be some detrimental
effects on ecosystem
[[Page 66811]]
function; 30.6 percent of total reef area within rated MPAs are in MPAs
rated as ``not effective'', defined as unmanaged or where management
was insufficient to reduce local threats in any meaningful way. Sixty-
nine percent of reef areas within MPAs are in MPAs that are unrated.
Effectiveness of protected areas depends not only on implementation
and enforcement of regulations, but also on reserve design; reserves
are not always created or designed with an understanding of how they
will affect biological factors or how they can be designed to meet
biological goals more effectively (Halpern, 2003). Even results from
the same regulatory scheme can differ between species within the
protected ecosystem. As such, global assessments are only moderately
informative and do not reflect important considerations in MPA
effectiveness on a regional or local scale. The results of one study on
Guam demonstrate that a reduction in fishing pressure had a positive
effect on the demography of Lethrinus harak through the significant
accumulation of older individuals in certain areas (Taylor and
McIlwain, 2010). Lethrinus harak is a reef fish that, similar to
bumphead parrotfish, constitutes an important part of many inshore
artisanal, commercial, and recreational fisheries (Carpenter and Allen,
1989). This species is easily targeted by fishers and heavily
exploited. On Saipan, the abundance of L. harak increased 4-fold (on
average) from 2000 to 2005 (Starmer et al., 2008); Taylor and McIlwain
(2010) attribute this increase not only to the recent ban on certain
fishing methods (SCUBA spearfishing and gill, drag, and surround nets)
but also the presence of well enforced MPAs. In Western Australia,
contrasting effects of MPAs were observed on the abundance of two
exploited reef fishes; a species of wrasse did not appear to respond to
protection, while the coral trout (a sea bass) showed a significant
increase in abundance after eight years of protection at two MPA sites
(Nardi et al., 2004). The authors note that, while MPAs are clearly an
effective tool for increasing the local abundance of some reef fishes,
the spatial and temporal scales required for their success may vary
among species. McClanahan et al. (2007) studied the recovery of coral
reef fishes through 37 years of protection at four marine parks in
Kenya and found that parrotfish biomass initially recovered rapidly,
but then exhibited some decline, primarily due to competition with more
steadily increasing taxonomic groups and a decline in smaller
individuals.
While a body of literature exists on MPA effectiveness, reserve
size, and design, Ban et al. (2011) found that the majority of these
studies originate from developed countries and/or present theoretical
models; as such, generally accepted recommendations on MPA reserve
design and management need to be adapted to the needs of developing
countries. Sixty-six percent of coral reef habitat in bumphead
parrotfish range is in fact in developing countries (as defined by the
Human Development Index; http://hdr.undp.org/en/countries/). Despite
the demonstrated effectiveness of no-take zones, the broader definition
of MPA to include other management regimes (time/area closures, gear
restrictions, zoning for controlled use and limitations) better
incorporates essential social aspects of communities in developing
coral reef countries (Ban et al., 2011).
MPA critics often point to problems with compliance and
enforcement. MPA size can affect both its effectiveness at conserving
the necessary space/resources for species to recover and compliance
rates. Kritzer (2003) found that noncompliance is more prevalent around
the boundaries of an MPA, and a single large MPA provides much greater
stability in both protected population size and yield at high fishing
mortality rates as noncompliance increases. As discussed previously,
customary governance systems exist in many countries where bumpheads
are found. The nature of a customary governance system would likely
result in many smaller MPAs as individual villages would manage their
local marine areas; however, customary governance is likely to have
high compliance (Fenner, 2012). Integrating local scale management into
larger regional planning schemes can further add to the effectiveness
of MPAs. Examples of where this combination of traditional institution
of marine protected or marine managed areas and integration of local
approaches into regional or national regulation has occurred within the
range of bumphead parrotfish include Fiji (Tawake et al., 2001; Gell
and Roberts, 2003; Ban et al., 2011; Mills et al., 2011;), Philippines
(Eisma-Osorio et al., 2009; Ban et al., 2011), Solomon Islands (Game et
al., 2010; Ban et al., 2011) American Samoa (Tuimavave, 2012) and Yap
State in the Federated States of Micronesia (Gorong, 2012).
A detailed evaluation of the 1,874 MPAs within the range of
bumphead parrotfish was beyond the scope of the management report.
Population monitoring data are so scarce for this species across most
of its range that even if these MPAs are positively affecting the
species, there is no documentation to reflect these changes. The
combination of local MPA establishment and customary governance and
enforcement, along with the trend toward integrating local management
regimes into regional scale planning in developing countries, is
encouraging for conservation. Based on these factors, along with the
existence of regulatory mechanisms and marine protected areas in
developed countries with more capacity for enforcement, we believe that
regulatory mechanisms throughout bumphead parrotfish range may confer
some conservation benefit to the species, although unquantifiable, and
the inadequacy of regulatory mechanisms is not a contributing factor to
increased extinction risk for the species.
Assessment of Existing Regulatory Mechanisms Relevant to Climate Change
Threats
In terms of coral reef protection, even if countries participating
in the current international agreements to reduce greenhouse gases were
able to reduce emissions enough and at a quick enough rate to meet the
goal of capping increasing average global temperature at 2[deg]C above
pre-industrial levels, there would still be moderate to severe
consequences for coral reef ecosystems (Hoegh-Guldberg, 1999; Bernstein
et al., 2007; Eakin, 2009; Leadley et al., 2010). Existing regulatory
mechanisms and conservation efforts targeting reduction in greenhouse
gases are therefore inadequate. However, the BRT Report concludes, and
we agree, that climate change threats are not thought to be primary
drivers of bumphead parrotfish population dynamics, either now or over
a 40-100 year future time horizon (Kobayashi et al., 2011; NMFS, 2012).
Overall Conclusions Regarding Inadequacy of Existing Regulatory
Mechanisms
Overall, existing regulatory mechanisms throughout the species'
global range vary in effectiveness in addressing the most serious
threats to the bumphead parrotfish. In many regions, a broad array of
national regulatory mechanisms, increase in MPAs, and resurgence of
customary management may be effective by addressing the two greatest
threats to the species, including adult harvest, as described above
under factor B, and loss and degradation of juvenile habitat, as
described above under factor A. We note, however, that because many of
these regulatory mechanisms are relatively new, their effectiveness
[[Page 66812]]
remains to be demonstrated. Moreover, regulatory mechanisms are not
deemed effective in addressing the threat of climate change, although
this threat is less important to bumphead parrotfish, as described
below under factor E. In conclusion, we find that existing regulatory
mechanisms are likely to have a positive, if undetermined, effect on
the conservation of species, and are not a contributing factor to
increased extinction risk for bumphead parrotfish.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Climate Change threats to bumphead parrotfish include global
warming and ocean acidification. The BRT Report states that overall,
climate change threats ``are not thought to be plausible drivers of
bumphead parrotfish population dynamics, either now or in the
foreseeable future''.
The BRT rated the severity of global warming as ``low''
historically, ``medium'' currently, and ``medium +'' over a 40-100 year
future time horizon. The BRT assigned a medium + ranking for global
warming threat severity in the future, because of the potential impact
of warmer seawater temperatures on pelagic life history stages.
Seawater temperature increases may affect fertilized eggs and larvae in
the pelagic environment by exceeding biological tolerances, and/or
indirect ecological effects, e.g., increasing oligotrophic areas
(Kobayashi et al., 2011).
The BRT rated the severity of ocean acidification as ``nil''
historically, ``nil +'' currently, and ``low -'' over a 40-100 year
future time horizon. The impacts of ocean acidification on coral
abundance and coral reefs are increasingly recognized (Hoegh-Guldberg
et al., 2007). However, since the bumphead parrotfish is not an
obligate corallivore, it may not be directly affected by ocean
acidification. This is because adult bumphead parrotfish do not appear
to be food-limited or space-limited in any portion of its range. The
species also appears to be adaptable to a variety of biotic and abiotic
conditions, given its wide geographic range. The existing nearshore
variability and the nearshore acid buffering capability both serve to
reduce the effects of climate change and ocean acidification on
bumphead parrotfish. Short- or long-term changes in ocean acidification
are unlikely to have a strong impact on bumphead parrotfish populations
unless it is via some unknown direct or indirect effect on three
dimensional refuge sites or egg/larval survival and subsequent
recruitment dynamics, as noted above for global warming (Kobayashi et
al., 2011).
The other threat considered under Factor E for which the BRT had
enough information to rank severity was recruitment limitation or
variability. The BRT Report evaluated the severity of this threat as
``low'' historically, ``medium'' currently, and ``medium +'' over a 40-
100 year future time horizon. Areas of the Great Barrier Reef, for
example, appear to be lacking juveniles. Both local retention and
incoming propagules may be demographically important, although their
relative importance is unknown. It remains unclear whether any
shortages of juveniles reflect shortages of egg/larval supply, or
instead are indicative of bottlenecks in older life history stages.
Since recruitment limitation is commonly documented in other reef fish
species, this is a plausible limiting factor for population growth of
this species (Kobayashi et al., 2011).
Synergistic Effects
In the status review, we evaluated the five factors individually
and in combination to determine the risk to the species. The BRT
determined that, with respect to factors A, B, C, and E, there are no
data to draw conclusions or even speculate on synergistic effects among
the factors. Given the lack of such data, it would be precautionary to
assume that any combination of hazards will work together with a net
effect greater than the sum of their separate effects. The BRT
recognizes that this species is extremely data poor and should be the
focus of continued study.
Existing regulatory mechanisms under Factor D can have impacts that
interact with existing threats under the other four factors by
potentially reducing the impacts of those threats and conferring some
conservation benefit to the species by regulating the human activities
posing the threat. Harvest is a threat that may be alleviated by
existing regulatory mechanisms like fisheries regulations and protected
areas. Harvest of adults was considered in the BRT Report to be one of
the two most important threats to the short- and long-term status of
bumphead parrotfish, but the BRT did not fully consider implications of
existing regulatory mechanisms in the 46 areas within the current range
of bumphead parrotfish addressing historical, current, or future
harvest-related threats to the species. These regulatory mechanisms may
provide important conservation benefits when considering the
significance of the current and future impact of harvest-related
threats to bumphead parrotfish, although they are unquantifiable.
Similarly, habitat degradation may be alleviated or mitigated by
regulatory mechanisms. A variety of regulatory mechanisms including a
recent increase in protected areas (as described above) are in place
throughout the range of bumphead parrotfish that may confer
conservation benefit to the species by addressing this threat.
Conservation Efforts
As described above, Section 4(a)(1) of the ESA requires the
Secretary to consider factors A through E above in a listing decision.
In addition, Section 4(b)(1)(A) requires the Secretary to consider
these five factors based upon the best available data ``after taking
into account those efforts, if any, being made by any State or foreign
nation * * * to protect such species, whether by predator control,
protection of habitat and food supply, or other conservation
practices.'' Section 4(b)(1)(A) authorizes us to more broadly take into
account conservation efforts of States and foreign nations including
laws and regulations, management plans, conservation agreements, and
similar documents, to determine if these efforts may improve the status
of the species being considered for ESA listing. The PECE policy
(described above) applies to conservation efforts that have yet to be
fully implemented or have yet to demonstrate effectiveness.
One purpose of the Management Report (NMFS, 2012) was to describe
and assess conservation efforts for the bumphead parrotfish throughout
its range. For the purposes of the status review, conservation efforts
are defined as non-regulatory or voluntary conservation actions
undertaken by both governmental and non-governmental organizations
(NGOs, e.g., conservation groups, private companies, academia, etc.)
that are intended to abate threats described in the BRT Report or are
incidentally doing so. Conservation efforts with the potential to
address threats to bumphead parrotfish include, but are not limited to:
fisheries management plans, coral reef monitoring, coral reef
resilience research, coral reef education and/or outreach, marine
debris removal projects, coral reef restoration, and others. These
conservation efforts may be conducted by countries, states, local
governments, individuals, NGOs, academic institutions, private
companies, individuals, or other entities. They also include global
conservation organizations that conduct coral reef and/or marine
environment conservation projects, global coral reef monitoring
networks and research projects, regional or global conventions, and
education and outreach projects throughout the range of bumphead
[[Page 66813]]
parrotfish. After taking into account these conservation efforts, as
more fully discussed in the management report (NMFS, 2012), our
evaluation of the Section 4(a)(1) factors is that the conservation
efforts identified may confer some conservation benefit to the species,
although the amount of benefit is undetermined. The conservation
efforts do not at this time positively or negatively affect our
evaluation of the Section 4(a)(1) factors or our determination
regarding the status of the bumphead parrotfish. The Management Report
also considered conservation efforts that have yet to be fully
implemented or have yet to demonstrate effectiveness (under the PECE
policy) and found that these conservation efforts do not at this time
positively or negatively affect the species status.
Extinction Risk Analysis
The Extinction Risk Analysis is the third step in the process of
making an ESA listing determination for bumphead parrotfish. For this
step, we completed an extinction risk analysis to determine the status
of the species. We asked the BRT to develop an extinction risk analysis
approach based on the best available information for bumphead
parrotfish. The extinction risk results in the BRT Report (Kobayashi et
al., 2011) are based on statutory factors A, B, C, and E listed under
section 4(a)(1) of the ESA. Factor D (``inadequacy of existing
regulatory mechanisms'') was assessed in the Management Report (NMFS,
2012) and this finding (above), and not considered by the BRT in its
extinction risk analysis for the species. Thus, a final extinction risk
analysis was done by determining whether the results of the BRT's
extinction risk analysis would be affected by the incorporation of
Factor D, thereby addressing the five 4(a)(1) factors. Following are
results of the BRT's extinction risk analysis based on factors A, B, C,
and E (Kobayashi et al., 2011), our determination with regard to
extinction risk based on factor D (NMFS 2011a), and a final extinction
risk determination for bumphead parrotfish based on all five factors.
Definitions
There are two situations in which NMFS determines that a species is
eligible for listing under ESA: (1) Where the species is in danger of
extinction, or is likely to become in danger of extinction in the
foreseeable future, throughout all its range; or (2) where the species
is in danger of extinction, or is likely to become in danger of
extinction in the foreseeable future, throughout a significant portion
of its range (SPOIR). Accordingly, as long as the species is in danger
of going extinct throughout a significant portion of its range, the
entire species is subject to listing and must be protected everywhere.
The first step the BRT took in developing an approach for bumphead
parrotfish extinction risk analysis was to define these spatial (SPOIR)
and temporal scales for application to the analysis. Next the BRT
defined a Critical Risk Threshold against which the status of the
species would be compared over these spatial and temporal scales
(Kobayashi et al., 2011). These three key definitions are described
below.
The ESA does not define the terms SPOIR or ``foreseeable future.''
In application, a portion of a species' range is generally considered
``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. Or put another way, we would not consider the portion of
the range at issue to be ``significant'' if there is sufficient
resiliency, redundancy, and representation elsewhere in the species'
range that the species would not be in danger of extinction throughout
its range if the population in that portion of the range in question
disappeared. When analyzing portions of a species' range, we consider
the importance of the individuals in that portion to the viability of
the species in determining whether a portion is significant, and we
consider the status of the species in that portion.
For purposes of the bumphead parrotfish, the BRT analyzed SPOIR
based on an ecological index consisting of five criteria, summarized
as: (1) Distance from the center of Indo-Pacific marine shore fish
biodiversity to account for the underlying biogeographic pattern; (2)
adult habitat area to account for adult habitat availability
importance; (3) juvenile habitat area to account for juvenile habitat
availability importance; (4) a connectivity measurement of outgoing
contributions to all other geographic strata to account for demographic
importance; and (5) a connectivity measurement of incoming
contributions from all other geographic strata to further account for
demographic importance (Kobayashi et al., 2011). Analyzing the
significance of the portion of the species' range in terms of its
biological importance to the conservation of the species is consistent
with NMFS' past practices as well as the Draft Policy on Interpretation
of the Phrase ``Significant Portion of Its Range'' (76 FR 76987;
December 9, 2011).
These 5 important ecological components were used in an additive
fashion to construct a composite SPOIR index, the median value of which
was 0.4506 over all geographic strata. Of 63 strata used by the BRT for
the current range of bumphead parrotfish, 32 strata had a SPOIR index
greater than the median value. These 32 strata were defined as SPOIR by
the BRT, and include American Samoa, Andaman and Nicobar, Australia,
Papua New Guinea, Cambodia, China, Christmas Island, Comoro Islands,
East Timor, India, Indonesia, Kenya, Madagascar, Malaysia, Maldives,
Mayotte, Micronesia, Mozambique, Myanmar, Timor Leste, Palau, Papua New
Guinea, Paracel Islands, Philippines, Seychelles, Solomon Islands,
Spratly Islands, Sri Lanka, Taiwan, Tanzania, Thailand, and Vietnam
(Kobayashi et al., 2011).
Following the completion of the BRT report, USFWS and NMFS
published 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). The Draft Policy has not yet been finalized as the Services
continue to evaluate comments and information received during the
public comment period. While the 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. Accordingly, we have
analyzed the BRT's findings in light of the Draft Policy to determine
whether this affects the SPOIR determination.
We apply the following principles from the Draft Policy to this
status review. First, 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, as appropriate, and the
Act's protections apply across the species' entire range. Second, the
range of a species is considered to be the general geographical area
within which that species can be found at the time of the particular
status determination. While lost historical range is relevant to the
analysis of the status of the species, it does not constitute a
significant portion of a species' range. Third, 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
[[Page 66814]]
subspecies. Finally, a portion of the species' range is significant if
its contribution to the viability of the species is so important that
without that portion, its abundance, spatial distribution,
productivity, and diversity would be so impaired that the species would
be in danger of extinction, either currently or in the foreseeable
future.
Under the Draft Policy, the determination of a portion's
``significance'' emphasizes its biological importance and contribution
to the conservation of the species. When determining a portion's
biological or conservation importance, we consider the species'
resiliency, or those characteristics that allow it to recover from
periodic disturbances. We also consider the species' redundancy (having
multiple aggregations distributed across the landscape, abundance,
spatial distribution) as a measure of its margin of safety to withstand
catastrophic events. Finally, we consider its representation (the range
of variation found in a species; spatial distribution, and diversity)
as a measure of its adaptive capability.
We have reconsidered the BRT's conclusions in light of the non-
binding guidance of the Draft Policy. As indicated above, the BRT
determined SPOIR first by identifying and qualitatively scoring five
ecologically significant components, and then by identifying the SPOIR
from those strata that scored higher than the median value. We believe
that the BRT's five ecologically significant components are consistent
with the Draft Policy's emphasis on identifying those biological
factors that are necessary to contribute to species viability--that is,
abundance, spatial distribution, productivity, and diversity. For
example, the identified SPOIR considered spatial structure that, if
removed, would result in isolated and fragmented remaining bumphead
populations. It also considered biologically important microhabitat
characteristics and connectivity of subareas to adjacent portions of
range, which are necessary to ensure continued productivity and
diversity to respond to future environmental changes.
We note that the BRT's additive approach may not capture all
possible combinations of demographic and population changes and
concentrations of threats that occur currently and might occur in the
future. The BRT in fact acknowledged that a combinational approach may
be more useful to determine SPOIR, but that it was not possible with
the limited information currently available.
Our next step in this evaluation under the Draft Policy was to
review all of the available information used in completing this status
review to identify any portions of the range of the species that
warrant further consideration (76 FR 77002; December 9, 2011). We
evaluated whether substantial information indicated ``that (i) the
portions may be significant [within the meaning of the Draft Policy]
and (ii) the species [occupying those portions] may be in danger of
extinction or likely to become so within the foreseeable future'' (76
FR 77002; December 9, 2011). Under the Draft Policy, both
considerations must apply to warrant listing a species as endangered or
threatened throughout its range based upon threats within a portion of
the range. In other words, if either consideration does not apply, we
would not list a species based solely upon its status within a
significant portion of its range.
Thus, in addition to the evaluation of ecological and biological
significance of portions of the range completed by the BRT, we
considered whether there are portions of the range in which threats are
so concentrated or acute as to place the species in those portions in
danger of extinction, and if so, whether those portions are
significant. No information presented in the BRT report, management
report, or that has otherwise been identified indicates a high
concentration of harvest or habitat degradation threats in one or more
specific portions within bumphead parrotfish range. The BRT rated the
geographic scope of each threat identified; adult harvest was rated as
``Localized'', defined as ``likely to be confined in its scope and to
affect the species in a limited portion of its range''. The BRT did not
identify any portions of the range where this threat may be
concentrated and this rating likely reflects the limited information
available specific to bumphead parrotfish harvest. Data pertaining to
harvest are sparse, incomplete, or lacking for a majority of regions
across the range and in most cases bumpheads are not distinguished in
the records from other parrotfish species. Of known fisheries
assessments, harvest information specific to bumphead parrotfish is
available for only five of the 63 strata evaluated by the BRT. The
records that exist for these five strata do not indicate any area of
exceptionally intensive harvest, and it is not possible to compare
these strata with other portions of the species range that lack similar
information. We found no further evidence during the status review of a
concentrated threat of harvest in any portion of the species' range.
The geographic scope for juvenile habitat loss and degradation was
rated by the BRT as ``Moderate'', defined as likely to be occurring at
more than some to many, but not all, areas in its scope and to affect
the species at a number of locations within its range. Again, specific
locations or portions of the range where this threat may be
concentrated were not identified by the BRT and we found no further
evidence that the threat of juvenile habitat loss is acutely
concentrated in any specific portions of the species' range. We
acknowledge that there are likely variations in the severity of threats
throughout the species' range but we have insufficient information to
conclude that any specific portion of the range warrants further
consideration due to acute or concentrated threats.
Finally, the BRT clarified that its qualitative method was only a
preliminary delineation of SPOIR for this species, and that the tool
was primarily useful as a relative reference because the ``absolute
magnitude of this SPOIR is not ecologically interpretable in present
form.'' We acknowledge that the BRT's approach in determining SPOIR is
a predictive judgment based on the best available--albeit limited--
science, and therefore must be used with caution. The BRT also
acknowledges that the selection of all strata with a SPOIR index above
the median value for inclusion in SPOIR was a conservative approach;
the species is able to persist in most, if not all, of the geographic
strata presented, therefore concerns of underestimating the actual
minimum threshold would appear unlikely; i.e., there is no compelling
evidence to suggest that the SPOIR index threshold should be greater
than the median, and is more likely lower than the median, hence it is
suggested that SPOIR was conservatively delineated in this exercise.
With respect to this relatively numerous, widely dispersed, and
interconnected species, we consider the BRT's approach to be an
appropriate tool for evaluating the biological importance of those
range portions that, if removed, would so impair the abundance, spatial
distribution, productivity, and diversity of the species that it would
be in danger of extinction. Our additional evaluation of portions of
the range that may warrant further consideration due to concentrated
threats does not support the delineation of any additional or different
portions of the species range as
[[Page 66815]]
significant. Accordingly, our SPOIR analysis remains the same when
considered in light of the non-binding guidance of the Draft Policy.
The BRT selected time frames over which identified threats are
likely to impact the biological status of the species and can be
reasonably predicted. The appropriate period of time corresponding to
the foreseeable future depends on the particular kinds of threats,
life-history characteristics, and specific habitat requirements for the
species under consideration. The bumphead parrotfish BRT selected 40
years as a working time frame, which is the approximate maximum age of
individuals of this species, keeping in mind the age at which most
females spawn is approximately 10 years, so that this reference point
spans approximately four bumphead parrotfish generations. As a means of
evaluating the sensitivity of this period, an independent vote was
taken examining 100 years (approximately 10 bumphead parrotfish
generations; Kobayashi et al., 2011).
Under the ESA, the determination of the foreseeable future is to be
made on a species-by-species basis through an analysis of the time
frames applicable to the threats to the particular species at issue,
including the interactive effect among those threats. Each threat may
have a different time frame associated with it over which we can
reliably predict impacts to the species. Our conclusion regarding the
future status of the species represents a synthesis of different time
frames associated with different threats.
Although available data for threats related to climate change allow
for reasonable projections over one hundred years, our ability to make
reliable predictions over this period based on existing data for other
threats affecting bumphead parrotfish, including the most serious
threats to the species (loss of juvenile habitat and adult harvest)
involves considerable uncertainty. We note that the BRT identified
significant levels of uncertainty regarding all aspects of bumphead
parrotfish biology. Although the BRT evaluated extinction risk over
distinct 40- and 100-year time horizons, the BRT analyzed the severity
of future impacts from identified threats and the certainty with which
they could make those conclusions over a combined 40- to 100-year time
horizon. Our determination of the foreseeable future necessarily
involves consideration of the most appropriate way to manage known
risks, and is bounded by the point where we can no longer make reliable
predictions as to the likely future status of this species.
Accordingly, while it was appropriate for the BRT to consider a time
frame of up to one hundred years to gauge the sensitivity of its
extinction analysis, for purposes of our determination, we believe that
a 40-year foreseeable future is more reliable for evaluating the future
conservation status of the species. Accordingly, we adopt this 40-year
period as the species' foreseeable future.
The BRT used a qualitative approach that characterizes extinction
risk in terms of the certainty that the species' condition will decline
below a Critical Risk Threshold (CRT) within a certain time period
because data allowing for a quantitative approach were not available.
The CRT is defined as a threshold below which the species is of such
low abundance or so spatially fragmented that it is at risk of
extinction. The CRT is not defined as a single abundance number,
density, spatial distribution or trend value; it is a qualitative
description encompassing multiple life-history characteristics and
other important ecological factors. Establishing the CRT level involves
consideration of all factors affecting the risk of bumphead parrotfish
extinction, including depensatory processes, environmental
stochasticity, and catastrophic events. Depensatory processes include
reproductive failure from low density of reproductive individuals and
genetic processes such as inbreeding. Environmental stochasticity
represents background environmental variation. Catastrophes result from
severe, sudden, and deleterious environmental events (Kobayashi et al.,
2011).
Extinction Risk Analysis Results
The BRT used a structured decision-making process of expert
elicitation to assess the extinction risk for bumphead parrotfish. To
account for uncertainty in the extinction risk analysis, each of the
five BRT members distributed 10 votes in three categories representing
likelihood of the species falling below the CRT. The three categories
were 0-33 percent, 33-66 percent, and 66-100 percent likelihood of the
species falling below the CRT. The average vote distribution amongst
the 3 categories for all five BRT members combined represents the BRT's
opinion of extinction risk. Extinction risk was evaluated at four
spatial-temporal scales (two time frames over both current range and in
SPOIR): (1) Current range at 40 years in the future; (2) current range
at 100 years in the future; (3) SPOIR at 40 years in the future; and
(4) SPOIR at 100 years in the future (Kobayashi et al., 2011).
For current range at 40 years in the future, the largest proportion
(56 percent) of the BRT's total votes fell into Category 1 (0-33
percent likelihood of falling below CRT), 40 percent fell into Category
2 (33-66 percent likelihood of falling below CRT), and 4 percent fell
into Category 3 (66-100 percent likelihood of falling below CRT;
Kobayashi et al. 2011).
For current range at 100 years in the future, the largest
proportion (48 percent) of the BRT's total votes again fell into
Category 1 (0-33 percent likelihood of falling below CRT), 46 percent
fell into Category 2 (33-66 percent likelihood of falling below CRT),
and 6 percent fell into Category 3 (66-100 percent likelihood of
falling below CRT; Kobayashi et al. 2011).
For SPOIR at 40 years in the future, the largest proportion (52
percent) of the BRT's total votes again fell into Category 1 (0-33
percent likelihood of falling below CRT), 42 percent fell into Category
2 (33-66 percent likelihood of falling below CRT), and 6 percent fell
into Category 3 (66-100 percent likelihood of falling below CRT;
Kobayashi et al. 2011).
For SPOIR at 100 years in the future, 46 percent of the BRT's total
votes fell into Category 1 (0-33 percent likelihood of falling below
CRT), 48 percent fell into Category 2 (33-66 percent likelihood of
falling below CRT), and 6 percent fell into the Category 3 (66-100
percent likelihood of falling below CRT; Kobayashi et al. 2011).
To summarize the BRT's extinction risk analysis results for the
four spatial-temporal scales, in three of the four scenarios examined,
the largest proportion of the BRT's votes were cast into Category 1 (0-
33 percent likelihood of falling below the CRT) and in one scenario
(SPOIR at 100 years) the largest proportion of their votes fell into
Category 2 (33-66% likelihood of falling below CRT).
The BRT's extinction risk results are based only on the statutory
factors A, B, C, and E listed under section 4(a)(1) of the ESA
(Kobayashi et al., 2011). The most significant threats to bumphead
parrotfish are adult harvest and juvenile habitat loss/degradation,
while juvenile harvest, adult habitat loss/degradation, pollution,
global warming, and ocean acidification were considered by the BRT to
be of medium threat (Kobayashi et al., 2011). Factor D (``inadequacy of
existing regulatory mechanisms'') was assessed in the Management Report
(NMFS 2012) and summarized in section D of the Threats Evaluation
above. Based on the information presented in the Management Report, we
conclude that the inadequacy of
[[Page 66816]]
regulatory mechanisms is not a factor contributing to increased
extinction risk for bumphead parrotfish. Extensive fisheries and
coastal management laws and decrees in the 46 areas within the current
range of the bumphead parrotfish exist. In addition, up to 25 percent
of adult and juvenile habitats are within protected areas. Ideally,
some proponents of marine reserve design recommend at least 20 to 30
percent or more of habitat be protected as a no-take areas (Bohnsack et
al., 2000; Airame et al., 2003; Fernandes et al., 2005; Gladstone 2007;
Gaines et al., 2010), although the actual area depends on the goal in
mind. Considering the entire range of bumphead parrotfish as one
ecosystem in order to apply this concept is not necessarily feasible;
however, as discussed previously, at least 12 per cent of coral reef
areas within bumphead parrotfish range are essentially no-take areas
for this species. We acknowledge that this percentage is lower than the
bar set for marine reserve design in the literature. We express no
conclusion on whether existing regulatory mechanisms should or could
provide greater protection to the bumphead parrotfish. We conclude only
that the inadequacy of regulatory mechanisms is not a factor
contributing to increased extinction risk of the species. The
Management Report also considered current conservation efforts as well
as conservation efforts that have yet to be fully implemented or have
yet to demonstrate effectiveness (under the PECE policy) and found that
these conservation efforts do not at this time positively or negatively
affect the species status. Accordingly, we conclude that the
information in the Management Report does not support an adjustment in
the BRT's extinction risk results. We therefore conclude after
considering all five factors that the BRT's extinction risk results
described above provide the best available information on the current
extinction risk faced by the bumphead parrotfish.
Listing Determination
As described above, we are responsible for determining whether the
bumphead parrotfish (Bolbometopon muricatum) warrants listing under the
ESA (16 U.S.C. 1531 et seq.). In order to make this listing
determination, we conducted a comprehensive status review, consisting
of a Biological Review, a Threats Evaluation, and an Extinction Risk
Analysis, as summarized above. Key conclusions are described below,
which provide the basis for our listing determination.
Key Conclusions From Biological Review
The species is made up of a single population over its entire
geographic range. As indicated above, the ESA requires us to determine
whether any species warrants listing as endangered or threatened. A
species includes any species, subspecies, ``and any distinct population
segment (DPS) of any species of vertebrate fish or wildlife which
interbreeds when mature.'' Under the joint USFWS-NOAA ``Policy
Regarding the Recognition of Distinct Vertebrate Population Segments
Under the Endangered Species Act'' (61 FR 4722; February 7, 1996) two
elements are considered when evaluating whether a population segment
qualifies as a distinct population segment (DPS) under the ESA: (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 species or subspecies to which it
belongs. If a population segment is discrete and significant (i.e., it
is a DPS), its evaluation for endangered or threatened status will be
based on the ESA's definitions of those terms and a review of the
factors enumerated in section 4(a). However, it should be noted that
Congress has instructed the Secretary to exercise this authority with
regard to DPS's ``sparingly and only when the biological evidence
indicates that such action is warranted.'' (Senate Report 151, 96th
Congress, 1st Session).
Under the DPS Policy, a population segment 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; 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. As discussed more fully above, prong (1) is not satisfied
because the species is made up of a single population over its entire
geographic range. In particular, the BRT report describes how available
observations and pelagic dispersal modeling support the conclusion that
the bumphead parrotfish is a single, well-described species that cannot
be sub-divided into distinct population segments.
Under the DPS policy, population segments also may be considered
discrete based on international political boundaries within which
differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant. Even assuming discreteness based on significant
differences in management or conservation status defined by political
boundaries for bumphead parrotfish, there is insufficient information
to conclude that the loss of any segment of the population defined by
those boundaries would be significant to the taxon as a whole.
Significance is evaluated based on a variety of factors, including
whether the DPS persists in an ecological setting unusual or unique for
the taxon, if there is evidence that loss of the DPS would result in a
significant gap in the range of a taxon, if there is evidence that the
DPS represents the only surviving natural occurrence of a taxon that
may be more abundant as an introduced population outside its historic
range, or if there is evidence that the DPS differs markedly from other
populations of the species in its genetic characteristics. We have no
evidence to conclude that any of these significance criteria apply to
the bumphead parrotfish. Specifically, there is no evidence to suggest
the existence of genetic differences between bumphead parrotfish in
different portions of the range. There is also no evidence to suggest
that the loss of any segment of the population would cause a
significant gap in the range of the taxon because the best available
science indicates one interconnected population throughout the species
range based on estimates of connectivity and a lack of evidence
indicating morphological, behavioral, or other regional differences.
Accordingly, we do not find that distinct population segments of
bumphead parrotfish exist.
The species has patchy abundance, being depleted or absent in many
areas while abundant in others. This conclusion is based on the
Abundance and Density section of the Biological Review, which describes
how the abundance of bumphead parrotfish varies widely across its
range. Patchy abundance throughout the range of a species is common and
due to differences in habitat quality/quantity or exploitation levels
at different locations. Pinca et al. (2011) examined the relative
importance of habitat variability and fishing pressure in influencing
reef fish communities across 17 Pacific Island countries and
territories; they found that the relative impact of fishing on fish
populations accounted for 20 percent of
[[Page 66817]]
the variance while habitat accounted for 30 percent.
The species possesses life history characteristics that increase
vulnerability to harvest, including slow growth, late maturation,
shallow habitat, nocturnal resting in refuge sites that are returned to
daily, large size, and conspicuous coloration. This conclusion is based
on the Age and Growth, Reproductive Biology, Habitat and Distribution,
and Settlement and Recruitment sections of the Biological Review.
Bumphead parrotfish grow slowly and mature at a large size, thus
juveniles and sub-adults can be large, attractive targets for harvest.
Sub-adult and adult bumphead parrotfish possess a multitude of life
history characteristics that increase vulnerability to harvest, such as
nocturnal resting behavior in shallow areas, diurnal feeding behavior
on shallow forereefs, large size, and conspicuous coloration. Several
of these traits have also been related to slow recovery rates for
severely depleted populations (Reynolds et al., 2001; Dulvy and
Reynolds, 2002; Dulvy et al., 2003; Reynolds, 2003).
The species possesses life history characteristics conducive to
population resilience including broad pelagic dispersal, frequent
spawning, and non-selective feeding. This conclusion is based on the
Movements and Dispersal, Reproductive Biology, Feeding, Ecosystem
Considerations sections of the Biological Review. Resiliency
(abundance, spatial distribution, productivity) describes
characteristics of a species that allow it to recover from periodic
disturbance, as defined in the NMFS/USFWS joint Draft SPOIR policy (76
FR 76987; 9 December 2011). The broad geographic range of bumphead
parrotfish includes areas of refuge where abundance is high and harvest
pressure is low. Although some unknown proportion of recruitment is
likely local in nature (Jones et al., 2009; Hogan et al., 2012), the
combination of high fecundity and broad pelagic dispersal of eggs and
larvae may contribute to replenishment of depleted areas at some level.
Non-selective feeding allows the species to be resilient to changes in
community composition within its habitat. In combination, these life
history characteristics contribute to population resilience.
The species is broadly distributed, and its current range is
similar to its historical range. This conclusion is based on the
Habitat and Distribution section of the BRT report, which concluded
that available information suggests that the current range is
equivalent to the historical range.
While abundance is declining across the species' range, the
contemporary population is estimated at 3.9 million adults. This
conclusion is based on the Contemporary Global Population and Global
Population Trends sections of the Biological Review. Available evidence
indicates a historical decline, and a continuing trend of decline,
although unquantifiable, in the global population of bumphead
parrotfish. The best estimate of contemporary global population
abundance of bumphead parrotfish is 3.9 million adults.
Key Conclusions From Threats Evaluation
The two most important threats to bumphead parrotfish are adult
harvest and juvenile habitat loss. Adult harvest and juvenile habitat
loss are both rated as ``high severity'' threats to the species, both
currently and over the next 40-100 years. All of the other threats to
the species were rated as lower severity, both currently and over the
next 40-100 years.
Existing regulatory mechanisms may provide benefits in addressing
the most serious threats to bumphead parrotfish. National and/or local
laws and regulations, many relatively new marine protected areas, and a
resurgence of customary management occurring across much of the range
of the species, may address both adult harvest and juvenile habitat
loss to an undetermined extent. The inadequacy of regulatory mechanisms
is not a contributing factor to increased extinction risk for the
species.
Existing regulatory mechanisms are at least as good within SPOIR as
outside of SPOIR. Of the 46 countries and areas within the range of the
bumphead parrotfish, 26 countries or parts thereof are considered to be
the ``significant portion of its range'' (SPOIR). Within these 26
areas, regulatory mechanisms are at least as effective as in the other
areas of the species' range.
Key Conclusions From Extinction Risk Analysis
Bumphead parrotfish are not likely to fall below the critical risk
threshold within the foreseeable future. In three of the four spatio-
temporal scenarios examined by the BRT, the largest proportion of the
BRT's votes indicate that bumphead parrotfish are 0-33 per cent likely
to fall below the CRT. Within SPOIR 100 years into the future, the
largest proportion (by a small margin) of the BRTs votes were that
bumphead parrotfish are 33-66% likely to fall below the CRT. Once
again, the CRT is defined as a threshold below which the species is of
such low abundance or so spatially fragmented that it is at risk of
extinction. As stated earlier, our conclusion is based on a synthesis
of multiple trends and threats over different time periods. The 40-year
time frame is a point beyond which our ability to predict the status of
the species when considering the best scientific and commercial
information available becomes more uncertain, including future impacts
from the primary threats of juvenile habitat loss and adult harvest.
Accordingly, so as to avoid basing our findings on speculation, we
adopt a 40-year time frame as the species' foreseeable future.
The BRT's extinction risk results are unchanged by the Management
Report. The BRT's extinction risk analysis was based on Factors A, B,
C, and E (Kobayashi et al., 2011). After also considering Factor D and
conservation efforts, based on information in the Management Report
(NMFS 2012), an adjustment in the BRT's extinction risk results is not
supported. We therefore conclude after considering all five factors
that the BRT's extinction risk results described above provide the best
available information on the current extinction risk faced by the
bumphead parrotfish.
Conclusion
Based on the key conclusions from the Biological Review, the
Threats Evaluation, and the Extinction Risk Analysis, we summarize the
results of our comprehensive status review as follows: (1) The species
is made up of a single population over a broad geographic range, and
its current range is indistinguishable from its historical range; (2)
while the species possesses life history characteristics that increase
vulnerability to harvest, it also possesses characteristics conducive
to population resilience; (3) although abundance is declining and
patchy across the species' range, the contemporary population size is
sufficient to maintain population viability into the foreseeable
future, based on the BRT's assessment of extinction risk; (4) existing
regulatory mechanisms throughout the species' range may be effective in
addressing the most important threats to the species (adult harvest and
juvenile habitat loss), but the extent of those conservation benefits
cannot be determined; and (5) while the global population is likely to
further decline, the combination of life history characteristics, large
contemporary population, and, to a lesser extent, existing regulatory
mechanisms indicate that the species is not currently in danger of
extinction,
[[Page 66818]]
nor is it likely to become in danger of extinction in the foreseeable
future.
These overall results of our status review portray a species that
still occupies its historical range, although at lower and declining
abundance, but with both biological characteristics and, potentially,
management measures that help maintain the population above the
viability threshold. Our information does not indicate that this status
is likely to change within the foreseeable future.
Based on these results, we conclude that the bumphead parrotfish is
not currently in danger of extinction throughout its range or
throughout SPOIR, and is not likely to become in danger of extinction
within the foreseeable future. Accordingly, the species does not meet
the definition of threatened or endangered. Based on these findings,
our listing determination is that the bumphead parrotfish does not
warrant listing as threatened or endangered at this time.
References
A complete list of all references cited herein is available upon
request (see FOR FURTHER INFORMATION CONTACT).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: November 2, 2012.
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.
[FR Doc. 2012-27244 Filed 11-6-12; 8:45 am]
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