Endangered and Threatened Species; Determination on the Designation of Critical Habitat for Three Scalloped Hammerhead Shark Distinct Population Segments, 71774-71784 [2015-29262]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 221 (Tuesday, November 17, 2015)]
[Notices]
[Pages 71774-71784]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-29262]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[Docket No. 150904820-5820-01]
RIN 0648-BF34


Endangered and Threatened Species; Determination on the 
Designation of Critical Habitat for Three Scalloped Hammerhead Shark 
Distinct Population Segments

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

ACTION: Notice of critical habitat determination.

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SUMMARY: We, NMFS, find that there are no marine areas within the 
jurisdiction of the United States that meet the definition of critical 
habitat for the Central and Southwest (Central & SW) Atlantic 
Distinction Population Segment (DPS), Indo-West Pacific DPS, or Eastern 
Pacific DPS of scalloped hammerhead shark. Based on a comprehensive 
review of the best available scientific and commercial data for use in 
the identification of critical habitat, we find that there are no 
identifiable physical or biological features that are essential to the 
conservation of these scalloped hammerhead DPSs and found within areas 
under U.S. jurisdiction, or any areas outside of the geographical area 
occupied by the listed DPSs under U.S. jurisdiction that are considered 
essential to their conservation. As such, we find that there are no 
specific areas under the jurisdiction of the United States that meet 
the definition of critical habitat.

DATES: This finding is made on November 17, 2015.

ADDRESSES: Electronic copies of the determination, list of references 
and supporting documents prepared for this action are available from 
the NMFS Office of Protected Resources Web site at https://www.fisheries.noaa.gov/pr/species/fish/scalloped-hammerhead-shark.html.

FOR FURTHER INFORMATION CONTACT: Maggie Miller, NMFS, Office of 
Protected Resources, (301) 427-8403.

SUPPLEMENTARY INFORMATION:

Background

    On July 3, 2014, we published a final rule to list the Central and 
Southwest (Central & SW) Atlantic Distinct Population Segment (DPS) and 
the Indo-West Pacific DPS of scalloped hammerhead shark (Sphyrna 
lewini) as threatened species under the

[[Page 71775]]

Endangered Species Act (ESA), and the Eastern Atlantic DPS and Eastern 
Pacific DPS of scalloped hammerhead sharks as endangered species under 
the ESA (79 FR 38213). Section 4(b)(6)(C) of the ESA requires the 
Secretary of Commerce (Secretary) to designate critical habitat 
concurrently with making a determination to list a species as 
threatened or endangered unless it is not determinable at that time, in 
which case the Secretary may extend the deadline for this designation 
by 1 year. At the time of listing, we concluded that critical habitat 
was not determinable at that time because: (1) Sufficient information 
was not currently available to assess impacts of designation; and (2) 
sufficient information was not currently available regarding the 
physical and biological features essential to conservation. We 
announced our intention to consider critical habitat for the Central & 
SW Atlantic, Indo-West Pacific, and Eastern Pacific DPSs in a separate 
rulemaking, and we requested relevant information from interested 
persons to help us: (1) Identify and describe the physical and 
biological features essential to the conservation of the scalloped 
hammerhead DPSs; and (2) assess the economic consequences of 
designating critical habitat for the DPSs. We solicited input from 
government agencies, the scientific community, industry and any other 
interested party on features and areas that may meet the definition of 
critical habitat for the DPSs that occur in U.S. waters or territories, 
but we did not receive any response to this solicitation. Subsequently 
we researched, reviewed, and compiled the best available scientific and 
commercial data available to be used in the identification of critical 
habitat for the Central & SW Atlantic, Indo-West Pacific, and Eastern 
Pacific DPSs. However, as discussed below, based on these data we find 
that there are no identifiable physical or biological features that are 
essential to the conservation of the scalloped hammerhead DPSs and 
found within areas under U.S. jurisdiction. As such, we find that there 
are no marine areas within U.S. jurisdiction that meet the definition 
of critical habitat.
    This finding describes information on the biology, distribution, 
and habitat use of scalloped hammerhead sharks and the methods used to 
identify areas that may meet the definition of critical habitat. In 
this determination, we focus on those aspects directly relevant to the 
designation of critical habitat for scalloped hammerhead sharks. For 
more detailed information on the biology and habitat use of scalloped 
hammerhead sharks, refer to the status review report (Miller et al. 
2014) and the proposed and final listing rules (78 FR 20717, April 5, 
2013; 79 FR 38213, July 3, 2014).

Scalloped Hammerhead Shark Biology and Status

    The following discussion of the life history and status of the 
scalloped hammerhead shark DPSs is based on the best scientific data 
available, including the Scalloped Hammerhead Shark Status Review 
Report (Miller et al. 2014).
    All hammerhead sharks belong to the family Sphyrnidae and are 
classified as ground sharks (Order Carcharhiniformes). Most 
hammerheads, including the scalloped hammerhead shark, belong to the 
Genus Sphyrna. The hammerhead sharks are recognized by their laterally 
expanded head that resembles a hammer, hence the common name 
``hammerhead.'' The scalloped hammerhead shark (Sphyrna lewini) is 
distinguished from other hammerheads by a marked central indentation on 
the anterior margin of the head, along with two more indentations on 
each side of this central indentation, giving the head a ``scalloped'' 
appearance.
    Scalloped hammerhead sharks can be found in coastal warm temperate 
and tropical seas worldwide. They occur over continental and insular 
shelves, as well as adjacent deep waters, but are seldom found in 
waters cooler than 22[deg] C (Compagno 1984; Schulze-Haugen and Kohler 
2003). These sharks range from the intertidal and surface to depths of 
up to 450-512 m (Sanches 1991; Klimley 1993), with occasional dives to 
even deeper waters (Jorgensen et al., 2009). They have also been 
documented entering enclosed bays and estuaries (Compagno 1984).
    Both juveniles and adult scalloped hammerhead sharks occur as 
solitary individuals, pairs, or in schools. The schooling behavior has 
been documented during summer migrations off the coast of South Africa 
as well as in permanent resident populations, like those in the East 
China Sea (Compagno 1984). Adult aggregations are most common offshore 
over seamounts and near islands, whereas neonate and juvenile 
aggregations are more common in nearshore nursery habitats (Compagno 
1984; Duncan and Holland 2006; CITES 2010; Hearn et al. 2010; Bejarano-
[Aacute]lvarez et al. 2011; Bessudo et al. 2011). It has been suggested 
that juveniles inhabit these nursery areas for up to or more than a 
year, as they provide valuable refuges from predation (Duncan and 
Holland 2006).
    The scalloped hammerhead shark is a high trophic level predator 
(trophic level = 4.1; Cort[eacute]s 1999) and opportunistic feeder with 
a diet that includes a wide variety of teleosts, cephalopods, 
crustaceans, and rays (Compagno 1984; Bush 2003; J[uacute]nior et al. 
2009; Noriega et al. 2011). In terms of reproduction, the scalloped 
hammerhead shark is viviparous (i.e., gives birth to live young), with 
a gestation period of 9-12 months (Branstetter 1987; Stevens and Lyle 
1989), which may be followed by a one-year resting period (Liu and Chen 
1999). Females attain maturity around 200-250 cm total length (TL) 
while males reach maturity at smaller sizes (range 128-200 cm TL). 
Parturition may be partially seasonal (Harry et al. 2011), with 
neonates present year round but with abundance peaking during the 
spring and summer months (Duncan and Holland 2006; Adams and Paperno 
2007; Bejarano-[Aacute]lvarez et al. 2011; Harry et al. 2011; Noriega 
et al. 2011). Females move inshore to birth, with litter sizes anywhere 
between 1 and 41 live pups. Observed maximum sizes for male scalloped 
hammerheads range from 196-321 cm TL, with the oldest male scalloped 
hammerhead estimated at 30.5 years (Piercy et al. 2007). Observed 
maximum sizes for female scalloped hammerheads range from 217-346 cm 
TL, with the oldest female scalloped hammerhead estimated at 31.5 years 
(Kotas et al. 2011).
    Based on the genetic diversity among subpopulations, geographic 
isolation, and differences in international regulatory mechanisms, we 
identified six DPSs of scalloped hammerhead sharks that are both 
discrete and significant to the taxon as a whole. The six scalloped 
hammerhead shark DPSs, which comprise the global population, are: (1) 
Northwest Atlantic and Gulf of Mexico DPS, (2) Central & SW Atlantic 
DPS, (3) Eastern Atlantic DPS, (4) Indo-West Pacific DPS, (5) Central 
Pacific DPS, and (6) Eastern Pacific DPS. All scalloped hammerhead 
sharks are both targeted and taken as bycatch in many global fisheries, 
with their fins a primary product for international trade. However, the 
exploitation by commercial and artisanal fisheries and lack of adequate 
regulatory mechanisms, combined with the species' biological 
vulnerability to depletion, has led to declines of the Eastern 
Atlantic, Eastern Pacific, Central & SW Atlantic, and Indo-West Pacific 
DPSs to the point where the Eastern Atlantic and Eastern Pacific DPSs 
are presently in danger of extinction and the Central & SW

[[Page 71776]]

Atlantic and Indo-West Pacific are likely to become so in the 
foreseeable future.

Critical Habitat Identification and Designation

    Critical habitat is defined by section 3 of the ESA as: ``(i) the 
specific areas within the geographical area occupied by the species, at 
the time it is listed . . ., on which are found those physical or 
biological features (I) essential to the conservation of the species 
and (II) which may require special management considerations or 
protection; and (ii) specific areas outside the geographical area 
occupied by the species at the time it is listed . . . upon a 
determination by the Secretary that such areas are essential for the 
conservation of the species.'' This definition provides a step-wise 
approach to identifying areas that may qualify as critical habitat for 
the listed scalloped hammerhead shark DPSs: (1) Determine the 
geographical area occupied by the species at the time of listing; (2) 
identify physical or biological habitat features essential to the 
conservation of the species; (3) delineate specific areas within the 
geographical area occupied by the species on which are found the 
physical or biological features; (4) determine whether the features in 
a specific area may require special management considerations or 
protection; and (5) determine whether any unoccupied areas are 
essential for conservation. Our evaluation and conclusions as we worked 
through this step-wise process are described in detail in the following 
sections.

Geographical Area Occupied by the Species

    We have interpreted ``geographical area occupied'' in the 
definition of critical habitat as the range of the species at the time 
of listing (45 FR 13011; February 27, 1980). Further, our regulations 
at 50 CFR 424.12(h) state: ``Critical habitat shall not be designated 
within foreign countries or in other areas outside of United States 
jurisdiction.'' The distribution of the Eastern Atlantic DPS of 
scalloped hammerhead shark is found entirely in waters outside of U.S. 
jurisdiction. As such, we cannot designate critical habitat for the 
Eastern Atlantic DPS and will focus the following discussion on the 
other three listed scalloped hammerhead DPSs: Eastern Pacific DPS, 
Central & SW Atlantic DPS, and Indo-West Pacific DPS.

Eastern Pacific DPS

    The Eastern Pacific DPS generally occurs off the coasts of Mexico 
and within the Gulf of California, from 32[deg]N latitude south to 
northern Peru, around 4[deg]S latitude. We characterize this 
geographical area as the ``core range'' or occupied area of the DPS 
(where one would most likely observe scalloped hammerhead sharks). This 
core range is entirely outside of U.S. jurisdiction. However, 
individuals of the species have been documented north and south of 
these core range boundary lines, but rarely and usually only during 
specific weather events. These observations primarily occur during 
strong El Ni[ntilde]o events, defined as a positive sea surface 
temperature (SST) departure from normal greater than or equal to 
+1.5[deg]C for 5 consecutive 3-month running mean SSTs, and represent 
an opportunistic northward displacement of the species (Siegel 1987; 
Shane 2001). It is important to note that these strong El Ni[ntilde]o 
events are only identified as such after they have already occurred 
(since they are based on 3-month running averages), and, as such, are 
difficult to forecast. There is no information that the areas off 
southern California and areas north, and off Peru and Chile, are now or 
were historically used as habitat for the species. Given the amount of 
fishing effort as well as the human population density in these 
regions, it is highly unlikely that substantial concentrations of 
scalloped hammerhead sharks would have passed unnoticed. As such, we 
consider these areas outside of the core range to be used solely by 
vagrants (individuals that occur outside of their normal range) and 
only during rare weather events that are difficult to forecast. Below 
we provide further information on the occupation and use of these areas 
to support this conclusion.
    In southern California waters (which are under U.S. jurisdiction), 
the first verified observation of a scalloped hammerhead shark was in 
1977 (Fusaro and Anderson 1980). Since then, observations have been 
sporadic and only associated with unusually warm water, as occurs 
during El Ni[ntilde]o Southern Oscillation (ENSO) events. Based on the 
available information, we found confirmation of 26 scalloped hammerhead 
individuals in southern California waters since 1977 (Fusaro and 
Anderson 1980; Siegel 1985; Lea and Rosenblatt 2000; Shane 2001; 
Galante 2014). The majority of these observations occurred immediately 
before, during, and following the strong 1997-1998 ENSO event (Lea and 
Rosenblatt 2000; Shane 2001). Between 1997 and 1999, 19 young-of-the-
year (YOY) (<100 cm TL) scalloped hammerhead sharks were caught in San 
Diego Bay (Shane 2001). Since 1999, only one scalloped hammerhead shark 
has been observed in southern California waters, caught on video by 
spear fishermen off Anacapa Island, Channel Islands in October of 2014 
(Galante 2014). The observed scalloped hammerhead sharks consist of 
adult female and juvenile sharks, suggesting that during strong El 
Ni[ntilde]o events, the species may use southern California waters as 
pupping and nursery grounds. The last strong (>=1.5[deg]C SST) El 
Ni[ntilde]o event to occur was in 1997-1998. Since then, there have 
been a number of weak (0.5 to 0.9[deg]C SST anomaly) and moderate (1.0 
to 1.4[deg]C SST anomaly) El Ni[ntilde]o events, but based on the 
observational data, these events do not appear to transform the 
southern California waters into occupiable habitat for the species.
    Similarly, in the central-south eastern Pacific, off the coasts of 
Peru and Chile, scalloped hammerhead observations are rare and also 
seem to be correlated with El Ni[ntilde]o events. A single reference to 
the occurrence of the species in waters of Peru points to the presence 
of the species off Puerto Pizzaro in 1998, which is located in northern 
Peru, very close to the border of Ecuador (Love et al. 2005). As 
mentioned previously, 1997-1998 registered as a strong El Ni[ntilde]o 
event, bringing much warmer waters to the eastern Pacific, and 
especially off the coast of Peru. This could explain the observation of 
the species in 1998, as, since then, no other observations of the 
species in the waters off Peru have been reported. In a recent paper 
that examined shark landings in Peru from 1996-2010, the authors found 
no records of scalloped hammerhead sharks (Gonzalez-Pestana et al. 
2014).
    In Chile, the first record of the species is from 2006 and is based 
on the genetic identification of three dried shark fins that were 
stored in a commercial warehouse for export to the international market 
(Sebastian et al. 2008). It is unclear where these scalloped hammerhead 
sharks were caught, but the authors suggest that many of the pelagic 
sharks are caught by the artisanal and industrial swordfish fisheries 
operating in Chile's exclusive economic zone (EEZ), and by the 
nearshore artisanal fisheries operating in north-central Chile. The 
sharks are generally landed at Coquimbo (29[deg]579 S, 71[deg]209 W); 
however, the authors obtained the three scalloped hammerhead shark fins 
from a storage warehouse in the town of Paico, in central Chile. This 
remains the only record of the species from Chile. Although the origin 
of the scalloped hammerhead sharks is uncertain, there was a weak El 
Ni[ntilde]o event that occurred

[[Page 71777]]

at the end of 2006 and could possibly explain the occurrence of these 
three sharks in Chilean waters at that time. However, given the 
extremely rare occurrence of the species in waters off Peru and Chile, 
even during El Ni[ntilde]o events, these areas do not likely contain 
habitat for the species.
    For the foregoing reasons, we find that the geographical area 
occupied by the Eastern Pacific DPS at the time of ESA listing is the 
previously-defined core range of the species, which extends over a 
broad area of the Eastern Pacific Ocean. Specifically, the geographical 
area occupied by the Eastern Pacific DPS includes all coastal and 
oceanic waters between 32[deg]N and 4[deg]S latitude, and follows the 
boundary lines of the DPS for longitude from 140[deg] W to 150[deg] W. 
We find that the geographical areas outside of this delineation where 
scalloped hammerhead sharks have been observed (i.e., areas off 
California, Peru and Chile) are used solely by vagrant individuals and 
only during rare weather events and, as such, are not identified as 
geographical areas occupied by the Eastern Pacific DPS at the time of 
listing. Given these findings, we conclude that there are no 
geographical areas occupied by the Eastern Pacific DPS that are within 
the jurisdiction of the United States at the time of listing.

Central & Southwest Atlantic DPS

    The geographic range of the Central & SW Atlantic DPS includes all 
coastal and oceanic waters from 28[deg] N. latitude to 36[deg] S. 
latitude, following the boundary lines designated for this DPS. 
Although this range covers the territorial waters of Puerto Rico and 
the U.S. Virgin Islands (USVI), as well as the Navassa Island National 
Wildlife Refuge, there is little to no available information on the 
occurrence or distribution of the scalloped hammerhead shark within 
these waters at the time of listing.
    Smooth, scalloped, and great hammerhead sharks are noted as 
historically occurring in USVI and Puerto Rican waters. In terms of 
habitat use around the USVI, personal communication (from E. Kadison, 
Ecology Laboratory Specialist, University of the Virgin Islands) 
suggests that Magens Bay, St. Thomas, may be a breeding ground for 
hammerheads, based on anecdotal reports of large aggregations found in 
the bay; however, the species of the hammerheads within Magens Bay was 
unknown (E. Kadison, personal communication, 2015). We could find no 
other information on the use of Magens Bay by hammerhead sharks that 
could help clarify or support the anecdotal reports. Similarly, Salt 
River Canyon off St. Croix's north shore was also noted as a diving 
spot for seeing the ``occasional'' large hammerhead, but species was 
not identified (N2Theblue 2014). The scalloped hammerhead shark is 
included in St. Croix's checklist of marine and inland fishes based 
only on records of two individuals that were caught as bycatch in 1991 
during fishing operations for bigeye scad (Tobias 1991; Smith-Vaniz and 
Jelks 2014). We also received a photo of a hammerhead shark from a 
researcher conducting a longline shark survey in the area, but upon 
inspection identified the shark as a great hammerhead (E. Kadison, 
pers. comm. 2015). In fact, the great hammerhead shark is noted as a 
``common Caribbean species'' in these waters, often found inshore and 
around coral reefs (Smith-Vaniz and Jelks 2014), and thus may likely be 
the species observed in the above anecdotal reports.
    In waters off Puerto Rico, we found no information on the present 
distribution or habitat use of scalloped hammerhead sharks. The only 
information indicating the species' historical occurrence in Puerto 
Rican waters is its inclusion in a 1974 technical report that provides 
the common names of fishes in Puerto Rico (Erdman 1974; revised in 
1983). Similarly, the presence and distribution of scalloped hammerhead 
sharks in the Navassa Island National Wildlife Refuge are unknown. In 
1998, seven scalloped hammerhead sharks were caught in the refuge 
during an exploratory longline fish research survey conducted by NMFS 
scientists (Grace et al. 2000), indicating its past occurrence in these 
waters. A number of more recent NOAA surveys have been conducted in the 
Navassa Island National Wildlife Refuge; however, these surveys have 
focused on the nearshore reef habitat and fish assemblages and do not 
report any observations of scalloped hammerhead sharks (Miller 2003; 
Piniak et al. 2006). As such, we have no information on the present 
occurrence of the species in the Navassa Island National Wildlife 
Refuge.
    Based on the foregoing information, we cannot establish if the 
geographical area occupied by the listed Central & SW Atlantic DPS 
includes any areas under the jurisdiction of the United States. 
Although scalloped hammerhead sharks have been included in historical 
checklists or observed in fish surveys conducted over 15 years ago, we 
have no information to indicate that the species was present in the 
territorial waters of Puerto Rico, USVI, or the Navassa Island National 
Wildlife Refuge at the time of listing. Because all three species of 
hammerhead sharks are noted as occurring in these waters, with the 
great hammerhead shark described as ``common,'' we cannot assume that 
the anecdotal reports of hammerhead sharks specifically refer to 
scalloped hammerhead sharks. As such, we consider the waters under U.S. 
jurisdiction within the Central & SW Atlantic DPS range to be 
unoccupied areas at the time of listing.

Indo-West Pacific DPS

    The geographic range of the Indo-West Pacific DPS includes all 
coastal and oceanic waters from 40[deg] N. latitude to 36[deg] S. 
latitude, and follows the boundary lines designated for this DPS.
    Although this range covers the territorial waters of Guam, 
Commonwealth of the Northern Mariana Islands (CNMI), American Samoa, 
and the Pacific Remote Island Areas (PRIAs), there is very little 
information on the occurrence, distribution, or use of habitat by the 
scalloped hammerhead shark within these waters at the time of listing. 
Most of the available information is based on personal observations and 
anecdotal reports of the species. In Guam, anecdotal reports suggest 
that Apra Harbor may have been used as a pupping ground for scalloped 
hammerhead sharks, based on the observed presence of young scalloped 
hammerhead sharks in Sasa Bay over a decade ago (D. Burdick, Research 
Associate, University of Guam, personal communication 2015). Over the 
time period of 1982-2004, a NMFS scientist working in Guam indicated 
that he personally observed and caught juvenile and adult scalloped 
hammerhead sharks in Apra Harbor (specifically the channel that 
connects the inner harbor and Sasa Bay) and observed juveniles near 
northern Piti, the Pago Bay river mouth, and the Ylig River mouth, and 
adults outside of Pago Bay and Tarague Beach (G. Davis, Assistant 
Regional Administrator for Habitat Conservation, NMFS, personal 
communication 2015). More recent observations, from Dr. Terry Donaldson 
(Professor, University of Guam), suggest that adults may periodically 
use Apra Harbor. He noted that he has personally observed them, albeit 
only very rarely over the past few years, in Apra Harbor and the inner 
harbor. The sharks occurred as solitary individuals (not schools), and 
he detailed one observation of a large adult feeding on a fish in the 
inner harbor. He also noted that neither he nor his technicians have 
observed any juveniles in Apra Harbor over the last few years.
    In terms of occurrence around the PRIAs, we received personal 
communication from NMFS research

[[Page 71778]]

scientists that they have observed and recorded scalloped hammerhead 
sharks around the islands as recently as 2012 (I. Williams, Research 
Fish Biologist, NMFS; K. Lino, Marine Ecosystems Research Coordinator, 
NMFS; personal communication 2014). Since 2000, NMFS scientists have 
conducted tow diver surveys every 3 years at the PRIAs, during which 
they are at each island for 3-5 days surveying the reef. The survey 
method consists of two divers pulled behind a vessel surveying for 
large fish (>50 cm TL) and also looking at the benthic habitat of the 
islands' fore reefs from 30-60 feet (9.1 m-18.3 m) depths. According to 
their observations and records, schools of adult scalloped hammerhead 
sharks are most commonly observed at Jarvis and Baker Islands, although 
adult individuals tend to be observed daily at many of the islands 
during the survey period. No juveniles have been recorded during these 
surveys.
    In addition, these NMFS scientists, who survey at more than 50 
U.S.-affiliated islands, atolls, and reefs, have never recorded 
scalloped hammerheads in American Samoa, Guam, or CNMI while conducting 
these reef surveys. Corroborating these observations, fishery observer 
data from 2006-2010 indicate that scalloped hammerhead sharks are also 
rarely observed caught in the American Samoa longline fishery, which 
primarily operates within the U.S. EEZ around American Samoa (Simmonds 
2014). We could find no information on the present occurrence or 
distribution of scalloped hammerhead sharks around CNMI.
    The above information gives us confirmation of the past and perhaps 
present occurrence of the species in U.S. waters within the range of 
the Indo-West Pacific DPS. Specifically, at the time of listing, the 
geographical areas occupied by the Indo-Pacific DPS likely include 
waters off Guam and the PRIAs. Although observations of scalloped 
hammerhead sharks in American Samoa waters are rare, they still occur 
and, thus, we cannot rule out that habitats in these waters were being 
used, at least periodically, at the time of listing. However, given the 
severe lack of information about or observations of scalloped 
hammerhead sharks within waters of CNMI, we cannot conclude that this 
area was occupied by the species at the time of listing.

Conclusion

    Based on the information above, we consider the geographical area 
occupied by Indo-West Pacific DPS of the scalloped hammerhead shark at 
the time of listing to include the waters under U.S. jurisdiction off 
Guam, the PRIAs, and American Samoa, and we consider the geographical 
areas occupied by the Eastern Pacific and Central & SW Atlantic DPSs at 
the time of listing to not include any waters under U.S. jurisdiction.

Physical or Biological Features Essential for Conservation

    Within the geographical area occupied by an endangered or 
threatened species at the time of listing, critical habitat consists of 
specific areas on which are found those physical or biological features 
essential to the conservation of the species (hereafter also referred 
to as ``essential features'') and that may require special management 
considerations or protection. Section 3 of the ESA (16 U.S.C. 1532(3)) 
defines the terms ``conserve,'' ``conserving,'' and ``conservation'' to 
mean: ``to use and the use of all methods and procedures which are 
necessary to bring any endangered species or threatened species to the 
point at which the measures provided pursuant to this chapter are no 
longer necessary.'' Further, our regulations at 50 CFR 424.12(b) for 
designating critical habitat state that physical and biological 
features that are essential to the conservation of a given species and 
that may require special management considerations or protection may 
include: (1) Space for individual and population growth, and for normal 
behavior; (2) food, water, air, light, minerals, or other nutritional 
or physiological requirements; (3) cover or shelter; (4) sites for 
breeding, reproduction, rearing of offspring, germination, or seed 
dispersal; and generally, (5) habitats that are protected from 
disturbance or are representative of the historic geographical and 
ecological distributions of a species.
    For scalloped hammerhead shark DPSs, we define conservation as the 
use of all methods and procedures necessary to bring scalloped 
hammerhead sharks to the point at which factors related to population 
ecology and vital rates indicate that the population is recovered in 
accordance with the definition of recovery in 50 CFR 402.02. Important 
factors related to population ecology and vital rates include 
population size and trends, range, distribution, age structure, gender 
ratios, age-specific survival, age-specific reproduction, and lifetime 
reproductive success. Based on the available knowledge of scalloped 
hammerhead shark population ecology and life history, we have 
identified four biological behaviors that are critical to the goal of 
increasing survival and population growth: (1) Feeding, (2) pupping, 
(3) migration, and (4) breeding. In the following section, we evaluate 
whether there are physical and biological features of the habitat areas 
known or thought to be used for these behaviors that are essential to 
the species' conservation because they facilitate or are intimately 
tied to these behaviors and, hence, support the life-history needs of 
the species. Because these behaviors are essential to the species' 
conservation, facilitating or protecting each one is considered a key 
conservation objective for any critical habitat designation for this 
species.

The Physical and Biological Features of Foraging Habitat That Are 
Essential to the Conservation of the Species

    Scalloped hammerhead sharks are opportunistic predators, with a 
high degree of trophic plasticity (Torres-Rojas et al. 2006; Rojas et 
al. 2014). They feed on a wide range of teleosts, crustaceans, and 
cephalopods (Klimley 1987; Torres-Rojas et al. 2006; Junior et al. 
2009; Hussey et al. 2011). As juveniles, when they occur primarily in 
inshore and shallow coastal waters, their diet is a reflection of their 
habitat and consists of small reef fish and crustaceans. For example, 
in K[amacr]ne'ohe Bay, a coastal bay of Hawaii consisting of a shallow 
reef, YOY scalloped hammered sharks (47-84 cm TL) were observed feeding 
mainly on scarids and gobioids abundant around the reef (Clarke 1971). 
The species of gobioids were characterized as ``rather ubiquitous and 
found in a variety of habitats in the bay'' (Clarke 1971). For those 
YOY that were captured in a part of the bay characterized by dead and 
silted reefs and an absence of reef fish, stomach analysis showed that 
these sharks primarily foraged on crustaceans (principally alpheids), 
suggesting the species, even at a young age, is not limited in its 
foraging habits but rather adapts to its present habitat and feeds on 
whatever prey is available (Clarke 1971). Similarly, in an analysis of 
stomach contents from 556 juvenile S. lewini, ranging from 48-160 cm 
TL, Torres-Rojas et al. (2006) identified 87 prey species and concluded 
that S. lewini is a generalist, un-selective feeder, with the type and 
amount of prey consumed by the juvenile sharks primarily determined by 
abundance and availability.
    The species is also thought to undergo an ontogenetic change in 
feeding habits. This change is estimated to occur when the species 
reaches sizes of around 100 cm TL (Klimley 1987; Torres-Rojas et al. 
2006; Kotas et al. 2012; Rojas et al. 2014). Generally, as the sharks 
become

[[Page 71779]]

larger, they begin to venture into neighboring deep-water habitats to 
feed on the larger pelagic fishes and squid. In their analysis, Torres-
Rojas et al. (2006) noted that scalloped hammerhead sharks <100 cm TL 
in the southern Gulf of California, Mexico, fed primarily on 
Loliolopsis diomedaea (46.7 percent Index of Relative Importance (IRI) 
in diet), a squid found in shallow waters, whereas sharks >100 cm TL 
had a diet consisting more of carangid fishes (30.6 percent IRI) and 
Abraliopsis affinis (33.9 percent IRI), a squid more commonly found in 
mid-depths and over continental shelves. Female scalloped hammerhead 
sharks are thought to undergo this ontogenetic shift in feeding habits 
at a smaller size than males, transitioning from juvenile foraging 
grounds in shallow, nearshore waters to foraging in pelagic, deeper 
water habitat. As Klimley (1987) observed in the Gulf of California, 
Mexico, females <=160 cm TL had a higher percentage of pelagic prey and 
much lower percentage of benthic prey in their diet compared to males 
of similar sizes, consistent with this type of foraging behavior. Off 
the coast of South Africa, Hussey (2011) observed that the diet 
signatures for female sharks of 161-214 cm TL indicated prolonged 
residence in offshore-pelagic waters (as opposed to continental shelf 
habitats). The diet signatures of males and females became similar only 
after male size increased to >214 cm TL. These findings also seem to 
corroborate those from a detailed tracking study of a juvenile female 
that was initially tagged in a nearshore nursery ground (La Paz Bay, 
Mexico) (Hoyos-Padilla et al. 2014). The female was 95 cm TL when 
tagged and spent the next 8 months primarily in shallow waters (<50 m 
depths), close to shore and near the surface (Hoyos-Padilla et al. 
2014). However, towards the end of the 10-month study period, the shark 
was tracked making an increasing number of deeper dives, between 150 to 
250 m depths, indicating a transition to offshore waters (Hoyos-Padilla 
et al. 2014). At the point of recapture, 10 months later, the shark had 
attained a size of 123 cm TL, which appears to fall within the 
estimated sizes above which juvenile females begin their ontogenetic 
migration (Klimley 1987; Torres-Rojas et al. 2006; Kotas et al. 2012; 
Rojas et al. 2014). Klimley (1987) suggests that this offshore 
migration occurs sooner for females, enabling them to achieve faster 
growth to reproductively-active sizes through access to a greater 
abundance of prey. This, in turn, translates to females achieving 
maturity at similar ages as their male counterparts (Klimely 1987).
    Although little is known regarding the foraging behavior of adults, 
based on tracking and diet studies, it is thought that adults (and sub-
adult females that have already migrated offshore) tend to exhibit a 
diel feeding pattern (Ketchum et al. 2014a, 2014b). During the day, 
sharks are observed refuging in large aggregations in shallow, 
nearshore coastal areas, off islands, and over seamount ridges (Klimley 
1985; Ketchum et al. 2014a, 2014b). They tend to stay in a small core 
area, making occasional vertical dives through the mixed layer, and 
generally remaining above the thermocline in waters >23 [deg]C (Bessudo 
et al. 2011; Ketchum et al. 2014a). These ``refuge'' areas tend to be 
located on the up-current side of islands and also correspond to where 
the pelagic assemblage is richer and represents lower-level trophic 
groups (such as trevally, pompano, and jacks) (Hearn et al. 2010; 
Bessudo et al. 2011; Ketchum et al. 2014a; 2014b; K. Lino, pers. comm. 
2014). One theory is that this specific location on the island/
seamounts, where the current splits to flow around obstacles, may cause 
an area of entrainment, providing the hammerheads with a food source 
upstream of the island (Hearn et al. 2010). Another theory is that the 
interactions between abrupt, sloping topography of seamounts and other 
bathymetrical features, and the impact of currents, tides, and internal 
waves, may enhance fluxes of near-bottom food particles, increasing 
abundance of benthic suspension feeders and further supporting higher 
densities of resident fish above seamounts (Mohn and Beckmann 2002; 
Hearn et al. 2010). However, feeding has not been observed at these 
refuge spots. Instead, it is thought that scalloped hammerheads may 
aggregate at these locations to reduce energy costs (these refuge spots 
are still areas of reduced currents relative to offshore) at areas that 
may provide some degree of food availability (with food-rich 
thermocline waters preferentially delivered to the up-current side of 
the island) and other benefits (such as cleaning stations), but that 
work more as a central and vantage location for foraging excursions 
into open waters (Ketchum et al. 2014a, 2014b). Based on tracking data, 
it is thought that individuals leave the adult aggregations at night to 
forage as solitary individuals in the neighboring deep-water pelagic 
habitats (Klimley and Nelson 1984, Klimley 1987, Klimley et al. 1988). 
Diet analysis shows that cephalopods, in particular, constitute an 
important prey item for adult scalloped hammerhead sharks. Deep-water 
squid species recorded in the stomachs of scalloped hammerhead sharks 
include: Ancistrocheirus lesueuri (Orbigny), Mastigoteuthis sp., 
Moroteuthis robustus (Verrill), Dosidicus gigas (Orbigny) (Klimley, 
1987), Histioteuthis sp., Ommastrephes bartramii and Cranchiidae 
(Junior et al. 2009). Many of these cephalopod species have a wide 
geographic distribution, moving throughout the deep waters of the 
ocean, and, as such, it would be difficult to link these prey species 
to any ``specific'' areas within the oceanic geographic areas occupied 
by the scalloped hammerhead DPSs.
    Overall, the best available information indicates that scalloped 
hammerhead sharks are opportunistic feeders. The species, regardless of 
life stage, does not appear to be limited by foraging grounds, adapting 
to its present habitat by feeding on whatever prey are available. There 
does not appear to be a specific prey species that is required to be 
present in a habitat for successful foraging to occur. Nor are there 
any specific habitat characteristics that appear to be intimately tied 
with feeding behavior. As such, we are unable to identify any 
particular physical or biological features of areas that facilitate 
successful foraging. While the above information suggests that 
scalloped hammerhead sharks may aggregate in tropical waters, near 
seamount ridges or productive coastal areas that face the impinging 
current, these areas are thought to be used more for refuging purposes 
as opposed to foraging habitats. Although these refuging habitats may 
be linked to foraging activities, this is purely speculative. 
Additionally, the particular physical or biological features of these 
refuging habitats that make them preferential for scalloped hammerhead 
aggregations are uncertain and their importance to the life-history 
needs of scalloped hammerhead sharks is unknown. Furthermore, no 
scalloped hammerhead sharks of the Central & SW Atlantic DPS or Eastern 
Pacific DPS have been observed refuging or foraging in the geographic 
areas under U.S. jurisdiction. The same holds true for the Indo-West 
Pacific DPS, with the exception of a single, personal observation of an 
adult scalloped hammerhead shark feeding on a large mullet in the Inner 
Harbor of Guam (T. Donaldson, pers. comm. 2014). For the foregoing 
reasons, it is not possible to identify any physical or biological 
features related to foraging that are essential to the conservation of 
the

[[Page 71780]]

species, nor are there any ``specific areas'' that appear to be used 
for foraging purposes within waters under U.S. jurisdiction.

The Physical and Biological Features of Pupping Habitat That are 
Essential to the Conservation of the Species

    Scalloped hammerhead sharks are known to give birth in warm 
tropical and temperate shallow, inshore waters. The specific nursery 
habitat requisites for such factors as temperature, depth, and 
substrate, are highly variable. Below is a summary of the information 
on the habitat characteristics of known scalloped hammerhead nursery 
areas, identified as such based on the: (1) Common presence of 
neonates, YOY, and juvenile scalloped hammerhead sharks in the area, 
(2) long residency period of immature individuals in these areas (e.g., 
weeks, months, years), and (3) repeated usage of the area over the 
years by these age classes (Salmon-Aguilar et al. 2009).
    Nursery habitats for scalloped hammerhead sharks are generally 
identified as shallow inshore areas, including bays and estuaries. 
K[amacr]ne'ohe Bay in Hawaii, for example, is a well-studied and 
confirmed nursery ground for scalloped hammerhead sharks (and is part 
of the range of the identified Central Pacific DPS, for which we 
determined listing was ``not warranted''; 78 FR 20717, April 5, 2013). 
K[amacr]ne'ohe Bay is the largest bay in the Hawaiian Islands (61 
km\2\), located on the windward side of Oahu, and is separated from the 
ocean by a large barrier reef (0-3 m deep) (Clarke 1971). There are 
also two channels that provide access to the ocean on either side of 
the bay, the North Channel (10 m deep) and the shallower Sampan Channel 
(3 m deep). Most of the bay is around 14 m deep, with the deepest spots 
at around 19 m. It has a muddy/silty bottom with temperatures ranging 
from 20-30 [deg]C. Patch reefs and small islands are interspersed 
throughout the bay. As mentioned above, the scalloped hammerhead 
population within this bay has been studied for many years (Clarke 
1971; Holland et al. 1993; Duncan and Holland 2006). The juveniles show 
a preference for the southern end of the bay, which is characterized as 
being more turbid and estuarine than the other parts of the bay. In 
fact, females tend to drop the pups in the bay at the start of the 
trade-wind season, which stirs up the bay and creates constantly turbid 
waters, allowing the juveniles to remain in the bay for a significant 
portion of the year (Clarke 1971). The preference for the turbid 
portions of the bay is thought to be a defense mechanism, protecting 
juveniles from predator visibility. Behavioral observations in this 
nursery habitat show that juveniles tend to refuge in aggregations 
during the day near the bottom (between 0.5 m and 1.5 m off the bay 
floor) and in deeper areas of the bay (Holland et al. 1993). At night, 
juveniles tend to disperse, possibly hunting where patch and fringing 
reef walls meet the bay floor (Holland et al. 1993).
    Identified nursery habitats in other regions also appear to share 
many of the same characteristics as those physical and biological 
features of K[amacr]ne'ohe Bay. For example, off the east coast of 
Australia, along the tropical northern Queensland coastline, there are 
a number of primarily shallow (<15 m) bays within which YOY scalloped 
hammerhead sharks of the Indo-West Pacific DPS have been observed 
(Simpfendorfer et al. 2014). These bays are protected seaward by the 
Great Barrier Reef and are also characterized by substrate that is 
dominated by silt and mudflats or mangrove-lined foreshores. The bays 
themselves tend to vary in other factors, such as freshwater input and 
seagrass abundance (Simpfendorfer et al. 2014). Young-of-the-year 
scalloped hammerheads have been observed in many of these bays 
(including Moreton, Rockhingham, Halifax, Cleveland, Bowling Green, 
Upstart, Repulse), but their spatial distribution indicates a 
preference for some (e.g., Rockingham, Cleveland, Repulse) more than 
others (Simpfendorfer and Millward 1993; Taylor 2008; Simpfendorfer et 
al. 2014; Australia Department of Environment 2014). The specific 
aspects of these bays that make them more preferential as nursery 
habitats over the others is not clear; although, based on information 
from Simpfendorfer et al. (2014), these bays receive a greater input of 
freshwater compared to some of the bays where scalloped hammerheads 
have not been observed. In Cleveland Bay, for example, freshwater flows 
from four creeks into the mangrove-dominated southern portion of the 
bay, causing significant drops in salinity in the summer (from 39% to 
36%) (Kinney et al. 2011). This is also the part of the bay where large 
numbers of YOY scalloped hammerheads have been recorded throughout the 
year in depths <5 m (Simpfendorfer and Milward 1993). Other physical 
aspects of the bay include silty substrates with mangrove-lined 
shorelines, areas of coastal reefs, and warm temperatures (SST ranges 
from 22.5 [deg]C in winter to 30.5 [deg]C in the summer) (Kinney et al. 
2011). In the intertidal surf zone of Cleveland Bay, which is 
characterized by mud and sand flats, neonates of S. lewini have also 
been caught, but this is a brief occurrence (Tobin et al. 2014). They 
appear to only be present during the summer, from October to January, 
in depths typically <0.5 m, and thus are assumed to utilize this area 
as either transient short-term protection from predators after birth or 
possibly for prey resources (shrimp, small fishes), after which the 
neonates disperse into the adjoining subtidal nursery area of Cleveland 
Bay (Tobin et al. 2014). This migration may explain why more S. lewini 
YOY were observed in the southern portion of the Bay from February to 
July (Simpfendorfer and Milward 1993).
    Apra Harbor, Guam, may also contain nursery habitat for the Indo-
West Pacific DPS of scalloped hammerhead sharks, but this supposition 
is based only on anecdotal observations of juvenile sharks in Sasa Bay 
and both adults and juveniles in the channel connecting the inner Apra 
Harbor and Sasa Bay (personal communication, G. Davis and D. Burdick 
2015). Sasa Bay, which is a no-take marine reserve, is a shallow bay 
(0-11 m) that primarily consists of sand/mud substrate, with patch 
reefs in deeper water and a mangrove swamp that extends along the 
coastline. The inner Apra Harbor has been extensively modified through 
dredging, construction activities, and landfills undertaken by the U.S. 
Navy since 1945 (Smith et al. 2009). The inner Apra Harbor now consists 
of a mud bottom of uniform depth, high turbidity, and an abundance of 
planktonic and benthic suspension feeders (compared to other parts of 
the harbor) but also has a relatively untouched mangrove area at the 
mouth of the Atantano River. Depths in the inner Apra Harbor range from 
0-11 m, with some deeper areas of 11-18 m (Smith et al. 2009). On the 
opposite side of the island, the Pago Bay river mouth has also been 
identified as an area where juvenile scalloped hammerhead sharks have 
been observed. This area consists of a fringing reef flat, shallow 
depths (<10 m) and temperatures that range from around 16 to 34 [deg]C 
(Tsuda 2004). Further information about the habitat use of scalloped 
hammerhead sharks that could provide insight into the specific physical 
or biological features within these systems that support the life-needs 
of the species is unknown, with the only available information from 
general personal observations and interactions with the species.
    Off South Africa, nursery habitats for the Indo-West Pacific DPS 
have been identified on the continental shelf off

[[Page 71781]]

the geopolitical provinces that encompass KwaZulu-Natal (KZN) and 
northern Eastern Cape. This area is characterized by a narrow 
continental shelf and steep continental slope bordered at its eastern 
edge by the warm south-westward flowing Agulhas Current (Hussey et al. 
2009). In Tugela Bank, KZN, YOY scalloped hammerheads were caught on 
trawling grounds in <50 m depths, where temperatures range from 21-27 
[deg]C. This area also coincides with the deepest deposit of mud 
originating from the discharges of numerous rivers in the area, and, as 
a result, the water is permanently turbid (Fennessy 1994). Young-of-
the-year scalloped hammerheads were also caught year-round in the 
Transkei area where temperatures range from 16.5-22 [deg]C (the coastal 
area just south of KZN), particularly the Port St Johns region which is 
the location of the mouth of the Mzimvbu River (Diemer et al. 2011). 
These temperatures and depths appear to be a bit cooler and deeper, 
respectively, than those described previously for nursery habitats in 
this DPS' range.
    In the range of the Eastern Pacific DPS, Zanella et al. (2009) 
noted significant catches of juvenile scalloped hammerhead sharks in 
the vicinity of the mouth of the Tarcoles River, Costa Rica. Within 
this area, YOY sharks primarily occurred in depths between 1 and 30 m, 
whereas larger juveniles occurred in deeper areas of 61-90 m. Most 
sharks were caught in the portion of the river mouth characterized by 
muddy substrate, and shallow and murky waters. This area, in 
particular, is characterized by higher sedimentation and nutrient flow 
due to the influence of a mangrove ecosystem surrounding the coast and 
river discharge from the Tarcoles River (Zanella et al. 2009).
    Other sites in the Eastern Pacific DPS range that have been 
identified as nursery areas are located in the Gulf of California and 
further south off the Pacific coast of Mexico. Sites in the Gulf of 
California include coastal waters off Mazatlan (Sinaloa) and San 
Francisquito and El Barril (Baja California). In the eastern Gulf of 
California, features of the areas where large numbers of YOY and 
juvenile S. lewini have been observed include both shallow and wide 
continental shelves (5-25 km), warm water temperatures, and highly 
productive waters. In 2014, Hoyos-Padilla et al. tracked an older 
juvenile female scalloped hammerhead shark in the Gulf of California 
(tagged in La Paz Bay) and found that the shark generally remained in 
depths less than 50 m, with a preference for temperatures of 23-26 
[deg]C. The onset of the birthing and nursery period in this area 
appears to be governed by temperature, when the temperatures increase 
from 18-19 [deg]C in the spring to 30-31 [deg]C in the summer. 
Significant upwelling events occur in the central and southern Gulf of 
California in winter and spring, generating high productivity and 
greater food availability during the peak breeding months and likely 
contribute to this area's importance as a nursery habitat for scalloped 
hammerhead sharks (Torres et al. 2008).
    The Gulf of Tehuantepec, off the southern coast of Mexico, is also 
thought to be an important spawning and nursery area for S. lewini 
based on the presence of YOY, juveniles, and pregnant females in these 
waters. It is characterized by a narrow continental shelf with rivers 
and temporal streams that form large coastal lagoons and estuaries, and 
well-developed mangrove forest communities that provide abundant food 
resources (Alego-plata et al. 2007; Rios-Jara et al. 2009).The region 
has a tropical warm sub-humid climate with an average annual 
temperature close to 26 [deg]C (range 14-31 [deg]C at 10 m depths; 
Tapia-Garcia et al. 2007). It also experiences numerous summer rains 
(annual rainfall = 2500-3000[thinsp]mm), making this region one of the 
wettest of Mexico (Rios-Jara et al. 2009). It is during the wet season 
that observations of YOY and juveniles increase, with birthing thought 
to occur in July and August. From October to May, this region 
experiences the strong ``Tehauntepec winds'' that cause the collapse of 
the thermocline and create upwelling of nutrients (Tapia-Garcia et al. 
2007), likely providing a source of greater food availability during 
the first years of growth for these juvenile sharks.
    From the best available information, the physical features of 
nursery areas in the Atlantic appear to be generally similar to those 
found in the Pacific. In the range of the Central & SW Atlantic DPS, 
Kotas et al. (2012) noted that in waters off Brazil pups tend to occur 
in shallow, coastal, turbid areas, in depths <20 m with sandy 
substrate. Juveniles are found near bays, estuaries, and over 
continental shelf in depths up to around 275 m (Kotas et al. 2012). No 
other information on nursery habitat characteristics for this DPS, 
especially those physical and biological features that directly support 
the life-history needs of the species, could be found. In fact, with 
the exception of the anecdotal information from Guam waters, there are 
no identified nursery grounds within waters under U.S. jurisdiction for 
either the Central & SW Atlantic DPS or the Indo-West Pacific DPS. The 
same is true for the Eastern Pacific DPS. Although YOY scalloped 
hammerhead sharks have been observed in U.S. waters off southern 
California, these individuals are identified as vagrants, with their 
occurrence associated only with rare strong ENSO events (Lea and 
Rosenblatt 2000; Shane 2001). In other words, the presence of YOY 
scalloped hammerhead sharks in California waters is not common, nor 
have scalloped hammerhead sharks displayed a repeated usage of these 
areas over the years. As such, we do not consider U.S. waters off 
southern California to contain identified nursery habitat for the 
Eastern Pacific DPS.
    Based on the foregoing information regarding known or presumed 
pupping areas for scalloped hammerhead sharks, the general physical 
oceanographic features that appear to be associated with this habitat 
include: (1) Relatively shallow inshore bays/estuaries with areas of 
moderate to high freshwater input; (2) tropical water temperatures 
(>=20 [deg]C); (3) muddy/silty/sandy substrate bottom; (4) presence of 
patchy reefs, mangrove systems, or seagrass beds; and (5) areas within 
inshore habitats of higher turbidity/current flow. However, because of 
the variability in the presence of the above physical features in the 
different identified nursery areas (e.g., mud versus silt or sand, low 
temperatures (16-22 [deg]C) versus higher temperatures (>30 [deg]C), 
varying levels of salinity and freshwater input, shallow depths (<10 m) 
versus areas with deeper waters (up to 275m)) we can only characterize 
nursery grounds using broad terms to describe the physical features. 
Given this level of resolution, and the fact that these features vary 
even for nursery grounds within a DPS' range, it is unclear which of 
the above physical characteristics, if any, are necessary to facilitate 
successful pupping behavior. In other words, we cannot identify whether 
any or a combination of these characteristics of nursery grounds are 
essential for the conservation of the species. Although scalloped 
hammerhead sharks may prefer areas that contain these characteristics, 
the available information does not allow us to identify any physical or 
biological features within these areas that are essential to support 
the life-history needs of scalloped hammerhead sharks. Additionally, 
while the available data suggest nursery habitats share many of the 
above physical characteristics, these general features are relatively 
ubiquitous throughout the global range of the species and not all areas 
with the

[[Page 71782]]

above features provide meaningful pupping or nursery habitat. 
Furthermore, there is no evidence of scalloped hammerhead sharks being 
limited to a specific nursery ground. In fact, Duncan et al.(2006) 
provided mtDNA data that argued against strong natal homing behavior by 
the species and anecdotal information of scalloped hammerhead sharks 
using artificially enlarged estuaries in Hawaii as nursery grounds 
(which were 100-600 km from confirmed nursery habitats). In other 
words, the species is highly migratory and does not appear to be 
limited to certain nursery areas.
    As mentioned previously, for the listed DPSs, there are no 
confirmed nursery grounds for the species in U.S. waters. Due to the 
rarity of the presence of the Central & SW Atlantic DPS in waters under 
U.S. jurisdiction, both historically and presently, these waters do not 
likely provide important pupping habitat. Similarly, the waters under 
U.S. jurisdiction in the Eastern Pacific are considered unoccupied 
areas used solely by vagrants of the Eastern Pacific DPS and only 
during rare weather events. As such, these waters do not provide 
important nursery habitat for the DPS. The anecdotal observations from 
Guam lend support to the potential use of waters under U.S. 
jurisdiction by juvenile scalloped hammerhead sharks; however, without 
knowledge of the essential features that create meaningful pupping 
grounds, we cannot identify any areas that meet the definition of 
critical habitat. Simply the observation of the presence of juveniles 
utilizing these waters (with unknown abundance, duration, habitat use, 
or frequency of occurrence) is not enough information to indicate that 
these areas contain physical and biological features that are essential 
to the conservation of the species. Additionally, the waters under U.S. 
jurisdiction for the Indo-West Pacific DPS represent an extremely small 
percentage of the suitable habitat available for the DPS (which 
comprises the waters of the entire Indian Ocean and Western Pacific 
Ocean), and based on the absence of any recent observations of juvenile 
scalloped hammerhead sharks utilizing waters off Guam, these waters 
under U.S. jurisdiction do not appear to contain important nursery 
habitat that could be characterized as essential for the conservation 
of the DPS.

The Physical and Biological Features of Migratory Habitat That Are 
Essential to the Conservation of the Species

    Both small and large-scale migratory movements are a necessary 
component in the life-history of the scalloped hammerhead shark. 
Examples of small scale migratory movements (<300 km) include those 
undertaken for feeding and refuging (Ketchum et al. 2014b; Diemer et 
al. 2011; Hearn et al. 2010; Klimley and Nelson 1984). Large scale 
migrations have also been observed by scalloped hammerhead sharks and 
are thought to occur for foraging but also reproductive purposes 
(Ketchum et al. 2014b; Bessudo et al. 2011). Pregnant females must make 
large scale migrations from their offshore habitats to coastal inshore 
nursery habitats for successful reproduction. Similarly, juvenile 
females are also thought to make this migration in the opposite 
direction as they attain larger sizes (>100 cm TL). The extent of 
juvenile and adult male migrations is unknown, but as some have been 
observed in schools offshore (Klimley 1985; Ketchum et al. 2014) and 
some in nearshore nursery areas (Clarke 1971; Dudley and Simpfendorfer 
2006), it is likely that a proportion of the male population may also 
undergo larger scale migrations. For logistical reasons, survey efforts 
have been focused in nearshore habitats, with a number of studies 
conducted around the island chains in the Eastern Tropical Pacific 
(Galapagos, Cocos Island, and Malpelo Island), part of the Eastern 
Pacific DPS range. For example, in the Galapagos, Ketchum et al. 
(2014b) tagged 134 scalloped hammerhead sharks, 80 percent of which 
were females. The most common movement exhibited by these sharks was 
short back and forth inter-island movement (<50 km), which was thought 
to represent focused foraging movements. However, five tagged scalloped 
hammerhead sharks were also tracked making long-distance migrations 
(>300 km) across the eastern Pacific, primarily during the warm season 
(March to May). One female (possibly mature with a size of 170 cm TL) 
was tracked moving from Wolf Island (Galapagos) to Cocos Island off 
Costa Rica, a distance of around 700 km. Two other female sharks (both 
likely mature, 200 cm TL) were tracked migrating from Darwin Island 
(Galapagos) to Cocos Island, a distance of 679 km. One of the females 
even returned to Darwin Island, indicating that these long distance 
migrations may be directed movements. Similarly, a female tagged at 
Malpelo Island (off Colombia) was tracked migrating to Cocos Island and 
then to Wolf and Darwin Islands. Results from another tagging study of 
scalloped hammerheads around Malpelo Island found many pregnant females 
leaving the island around March-April (Bessudo et al. 2011). As pupping 
tends to occur in the summer months off the continental Eastern Pacific 
(Torres et al. 2008; Rios-Jara et al. 2009; Zanella et al. 2009), it is 
thought that these long distance and seemingly directed movements 
across the Eastern Pacific may be conducted by female sharks during the 
final stages of the gestation period, with the sharks likely migrating 
to the continental coast for parturition (Bessudo et al. 2011; Ketchum 
et al. 2014b). Additionally, in the Ketchum et al. (2014b) study, one 
mature male scalloped hammerhead shark (218 cm TL) was also tracked 
making a long-distance migration. The shark travelled from Darwin 
Island to Malpelo Island (a distance of 627km) (Ketchum et al. 2014b). 
Given that this migration occurred during the same season as the female 
long-distance migrations, it could be that a small proportion of the 
mature male population may also undergo long-distance migrations, 
following reproductively active females to coastal nursery habitats for 
mating purposes.
    Although the available information suggests that these sharks do 
undergo short and long-distance migrations, the space or migratory 
corridor used by scalloped hammerhead sharks during these migrations 
remains unknown. In addition, we are not aware of any migratory 
tracking studies that have been conducted in waters under U.S. 
jurisdiction and, therefore, have no information on any potential 
migratory corridors that may exist within waters under U.S. 
jurisdiction for the listed scalloped hammerhead DPSs. Based on the 
foregoing information, we cannot identify any specific essential 
features that define migratory habitat for scalloped hammerhead sharks.

The Physical and Biological Features of Breeding Habitat That Are 
Essential to the Conservation of the Species

    Important areas for mating are largely unknown for scalloped 
hammerhead sharks. To identify potential sites as mating grounds, we 
looked for the presence of both mature females and males. For the most 
part, adult females are usually found schooling offshore with subadult 
females (Klimley 1985; Ketchum et al. 2014b). Studies have documented 
that these schools also consist of a few adult males (Klimley 1985; 
Ketchum et al. 2014a, 2014b). As such, potential mating events may 
occur in these offshore refuging schools, but this has not been 
confirmed. Furthermore, none of these refuging schools described above 
have been observed in waters under U.S. jurisdiction for the listed 
scalloped hammerhead DPSs.

[[Page 71783]]

    Additionally, adult females, including ones that have recently 
given birth, are occasionally observed in identified nursery habitats 
along with adult males (Clark 1971; Dudley and Simpfendorfer 2006; 
Hussey et al. 2011). It is thought that mating may also occur during 
the principal pupping season, and potentially near these nursery areas 
(possibly over continental shelf or even near shelf slope; Kotas et al. 
2012), with adult females moving inshore for a short time to mate and 
then proceeding to migrate offshore (Clarke 1971). Adult males, 
however, tend to be observed in larger numbers (sometimes with no 
evidence of mature females) staying in these inshore areas for longer 
periods of time, perhaps as a way to maximize the number of breeding 
females they can encounter (Clarke 1971; Dudley and Simpfendorfer 2006; 
Hussey et al. 2011; Yates et al. 2015). However, as stated above, the 
areas where scalloped hammerhead shark mating occurs remain unknown and 
purely speculative. There has not been any systematic evaluation of the 
particular physical or biological features that facilitate or are 
necessary for mating to occur. As such, we cannot identify physical or 
biological features of breeding habitat that are essential to the 
conservation of the species.

Unoccupied Areas

    Section 3(5)(A)(ii) of the ESA defines critical habitat to include 
specific areas outside the geographical area occupied by a threatened 
or endangered species at the time it is listed if the areas are 
determined by the Secretary to be essential for the conservation of the 
species. Regulations at 50 CFR 424.12(e) specify that we shall 
designate as critical habitat areas outside the geographical area 
presently occupied by a species only when a designation limited to its 
present range would be inadequate to ensure the conservation of the 
species. Our regulations at 50 CFR 424.12(h) also state: ``Critical 
habitat shall not be designated within foreign countries or in other 
areas outside of United States jurisdiction.''
    As discussed previously, the waters off California are not 
considered part of the geographical area occupied by the Eastern 
Pacific DPS at the time of listing. We also conclude that it is not an 
unoccupied area essential to the DPS' conservation, given the rare, 
errant use of the area by vagrant scalloped hammerhead sharks in the 
past, with this use associated only with sporadic weather events, and 
the fact that we have no information to suggest the area is essential 
to the conservation of the DPS. Furthermore, for the areas under U.S. 
jurisdiction off USVI, Puerto Rico, Navassa Wildlife Refuge, and CNMI, 
which we could not conclude were occupied by the applicable scalloped 
hammerhead DPSs at the time of listing, we found no information that 
would indicate these areas are essential for the conservation of the 
listed DPSs. Scalloped hammerhead sharks are highly migratory, and 
although they may have historically been observed in these waters, the 
lack of historical or anecdotal data or information tends to suggest 
these may have been rare or sporadic occurrences as the shark passed 
through these waters. We do not find that these unoccupied areas under 
U.S. jurisdiction, which additionally comprise such small portions of 
the overall ranges of the listed DPSs, are essential to the 
conservation of the listed DPSs. As such, we find that there are no 
identifiable areas outside the geographical areas occupied by the 
listed DPSs that would meet the definition of critical habitat for the 
scalloped hammerhead shark DPSs.
    Any conservation actions for the listed scalloped hammerhead shark 
DPSs that would bring these DPSs to the point that the measures of the 
ESA are no longer necessary will need to be implemented by foreign 
nations. As noted in the final rule (79 FR 38213, July 3, 2014), the 
significant operative threats to the listed scalloped hammerhead DPSs 
are overutilization by foreign industrial, commercial, and artisanal 
fisheries and inadequate regulatory mechanisms in foreign nations to 
protect these sharks from the heavy fishing pressure and related 
mortality, with illegal fishing identified as a significant problem in 
areas outside of U.S. jurisdiction. Thus, recovery of the listed DPSs 
is highly dependent upon international conservation efforts. This 
includes increased protection for the listed DPSs from fishery-related 
mortality, especially within those foreign areas described above where 
the biological behaviors that support the life-history needs of the 
listed DPSs have been observed (e.g., the identified nursery grounds in 
foreign waters). We are committed to increasing the awareness of the 
threats to these listed DPSs and encourage the development of 
conservation programs by foreign nations and international regulations 
to protect these DPSs. For example, we recently collaborated with a 
coalition of countries to gain support for a proposal to add three 
hammerhead shark species (scalloped, smooth, and great) to Appendix II 
of the Convention on the International Trade in Endangered Species of 
Wild Fauna and Flora (CITES). In March 2013, at the 16th Meeting of the 
Conference of the Parties to CITES, member nations, referred to as 
``Parties,'' voted in support of this proposal, an action that will 
complement existing international shark protection measures by ensuring 
trade of these hammerhead shark species is sustainable and does not 
threaten their survival. We will continue to be a leader in promoting 
the conservation and management of sharks globally, and will work 
internationally within regional fisheries management organizations and 
other international bodies to promote the adoption of conservation and 
management measures, particularly for the listed scalloped hammerhead 
shark DPSs.

Critical Habitat Determination

    Given the best available information and the above analysis of this 
information, we find that there are no identifiable occupied areas 
under the jurisdiction of the United States with physical or biological 
features that are essential to the conservation of the species or 
unoccupied areas that are essential to the conservation of the species. 
Therefore, we conclude that for the Eastern Pacific DPS, Central & SW 
Atlantic DPS, and the Indo-West Pacific DPS, there are no specific 
areas within their respective ranges and under U.S. jurisdiction that 
meet the definition of critical habitat. Since there is not any habitat 
of scalloped hammerhead sharks in waters under U.S. jurisdiction that 
is considered to be critical habitat, there is no critical habitat to 
designate under ESA section 4(a)(3)(A)(i).
    Although we have determined that no areas meet the definition of 
critical habitat for the listed scalloped hammerhead DPSs, the areas 
occupied by the DPSs under U.S. jurisdiction will continue to be 
subject to conservation actions implemented under section 7(a)(1) of 
the ESA, as well as consultation pursuant to section 7(a)(2) of the ESA 
for Federal activities that may affect the listed scalloped hammerhead 
DPSs, as determined on the basis of the best available information at 
the time of the action. Through the consultation process, we will 
continue to assess effects of Federal actions on these species and 
their habitat. In addition, the prohibitions against importing, 
exporting, engaging in foreign or interstate commerce, or ``taking'' of 
the scalloped hammerhead sharks of the Eastern Pacific DPS and Eastern 
Atlantic DPS under section 9 of the ESA continue to apply.

[[Page 71784]]

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 10, 2015.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
[FR Doc. 2015-29262 Filed 11-16-15; 8:45 am]
 BILLING CODE 3510-22-P