Endangered and Threatened Species; Determination of Nine Distinct Population Segments of Loggerhead Sea Turtles as Endangered or Threatened, 58868-58952 [2011-23960]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration
• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 76, Number 184 (Thursday, September 22, 2011)]
[Rules and Regulations]
[Pages 58868-58952]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-23960]



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Vol. 76

Thursday,

No. 184

September 22, 2011

Part II





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Parts 223 and 224





Endangered and Threatened Species; Determination of Nine Distinct 
Population Segments of Loggerhead Sea Turtles as Endangered or 
Threatened; Final Rule

Federal Register / Vol. 76, No. 184 / Thursday, September 22, 2011 / 
Rules and Regulations

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Parts 223 and 224

[Docket No. 100104003-1068-02]
RIN 0648-AY49


Endangered and Threatened Species; Determination of Nine Distinct 
Population Segments of Loggerhead Sea Turtles as Endangered or 
Threatened

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce; United States Fish and 
Wildlife Service (USFWS), Interior.

ACTION: Final rule.

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SUMMARY: We (NMFS and USFWS; also collectively referred to as the 
Services) have determined that the loggerhead sea turtle (Caretta 
caretta) is composed of nine distinct population segments (DPSs) that 
constitute ``species'' that may be listed as threatened or endangered 
under the Endangered Species Act (ESA). In this final rule, we are 
listing four DPSs as threatened and five as endangered under the ESA. 
We will propose to designate critical habitat for the two loggerhead 
sea turtle DPSs occurring within the United States in a future 
rulemaking. We encourage interested parties to provide any information 
related to the identification of critical habitat and essential 
physical or biological features for this species, as well as economic 
or other relevant impacts of designation of critical habitat, to assist 
us with this effort.

DATES: This rule is effective on October 24, 2011.

ADDRESSES: This final rule and comments and materials received, as well 
as supporting documentation used in the preparation of this rule, are 
available on the Internet at https://www.regulations.gov and will be 
available for public inspection, by appointment, during normal business 
hours at: National Marine Fisheries Service, Office of Protected 
Resources, 1315 East West Highway, Room 13657, Silver Spring, MD 20910. 
You may submit information related to the identification of critical 
habitat for the loggerhead sea turtle by either of the following 
methods:
     Mail: NMFS National Sea Turtle Coordinator, Attn: 
Loggerhead Critical Habitat Information, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Room 13657, 
Silver Spring, MD 20910 or USFWS National Sea Turtle Coordinator, U.S. 
Fish and Wildlife Service, 7915 Baymeadows Way, Suite 200, 
Jacksonville, FL 32256.
     Fax: To the attention of NMFS National Sea Turtle 
Coordinator at 301-427-2522 or USFWS National Sea Turtle Coordinator at 
904-731-3045.
    Instructions: All information received will be a part of the public 
record. All personal identifying information (for example, name, 
address, etc.) voluntarily submitted by the public may be publicly 
accessible.

FOR FURTHER INFORMATION CONTACT: Barbara Schroeder, NMFS, at 301-427-
8402; Sandy MacPherson, USFWS, at 904-731-3336; Marta Nammack, NMFS, at 
301-427-8403 or Lorna Patrick, USFWS, at 850-769-0552 ext. 229. Persons 
who use a Telecommunications device for the deaf (TDD) may call the 
Federal Information Relay Service (FIRS) at 1-800-877-8339, 24 hours a 
day, 7 days a week.

SUPPLEMENTARY INFORMATION: 

Background

    We issued a final rule listing the loggerhead sea turtle as 
threatened throughout its worldwide range on July 28, 1978 (43 FR 
32800). On July 12, 2007, we received a petition to list the ``North 
Pacific populations of loggerhead sea turtle'' as an endangered species 
under the ESA. NMFS published a notice in the Federal Register on 
November 16, 2007 (72 FR 64585), concluding that the petitioners 
(Center for Biological Diversity and Turtle Island Restoration Network) 
presented substantial scientific information indicating that the 
petitioned action may be warranted. Also, on November 15, 2007, we 
received a petition to list the ``Western North Atlantic populations of 
loggerhead sea turtle'' as an endangered species under the ESA. NMFS 
published a notice in the Federal Register on March 5, 2008 (73 FR 
11849), concluding that the petitioners (Center for Biological 
Diversity and Oceana) presented substantial scientific information 
indicating that the petitioned action may be warranted.
    In early 2008, NMFS assembled a Loggerhead Biological Review Team 
(BRT) to complete a status review of the loggerhead sea turtle. The BRT 
was composed of biologists from NMFS, USFWS, the Florida Fish and 
Wildlife Conservation Commission, and the North Carolina Wildlife 
Resources Commission. The BRT was charged with reviewing and evaluating 
all relevant scientific information relating to loggerhead population 
structure globally to determine if any population met the criteria to 
qualify as a DPS and, if so, to assess the extinction risk of each DPS. 
The findings of the BRT, which are detailed in the ``Loggerhead Sea 
Turtle (Caretta caretta) 2009 Status Review under the U.S. Endangered 
Species Act'' (Conant et al., 2009; hereinafter referred to as the 
Status Review), addressed DPS delineations, extinction risks to the 
species, and threats to the species. The Status Review underwent 
independent peer review by nine scientists with expertise in loggerhead 
sea turtle biology, genetics, and modeling. The Status Review is 
available electronically at https://www.nmfs.noaa.gov/pr/species/statusreviews.htm.
    On March 12, 2009, the petitioners (Center for Biological 
Diversity, Turtle Island Restoration Network, and Oceana) sent a 60-day 
notice of intent to sue to the Services for failure to make 12-month 
findings on the petitions by the statutory deadlines (July 16, 2008, 
for the North Pacific petition and November 16, 2008, for the Northwest 
Atlantic petition). On May 28, 2009, the petitioners filed a Complaint 
for Declaratory and Injunctive Relief to compel the Services to 
complete the 12-month findings. On October 8, 2009, the petitioners and 
the Services reached a settlement in which the Services agreed to 
submit to the Federal Register a 12-month finding on the two petitions 
on or before February 19, 2010. On February 16, 2010, the United States 
District Court for the Northern District of California modified the 
February 19, 2010, deadline to March 8, 2010.
    On March 16, 2010 (75 FR 12598), the Services published in the 
Federal Register combined 12-month findings on the petitions to list 
the North Pacific populations and the Northwest Atlantic populations of 
the loggerhead sea turtle as DPSs with endangered status, along with a 
proposed rule to designate nine loggerhead sea turtle DPSs worldwide 
and to list two of the DPSs as threatened and seven as endangered. The 
Federal Register notice also announced the opening of a 90-day public 
comment period on the proposed listing determination.
    The Services subsequently received a request from the Maryland 
Department of Natural Resources for a public hearing to be held in 
Maryland. On June 2, 2010 (75 FR 30769), the Services published a 
notice in the Federal Register announcing our plans to hold

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a public hearing on the proposed actions on June 16, 2010. The Federal 
Register notice also announced a re-opening of the public comment 
period for an additional 90 days. The June 16, 2010, public hearing was 
held at the Ocean Pines Public Library in Berlin, Maryland.
    On March 22, 2011 (76 FR 15932), the Services published in the 
Federal Register a notice announcing a 6-month extension of the 
deadline for a final listing decision to address substantial 
disagreement on the interpretation of data related to the status and 
trends for the Northwest Atlantic Ocean DPS of the loggerhead sea 
turtle and its relevance to the assessment of risk of extinction. At 
this time, we solicited new information or analyses from the public 
that would help clarify this issue. The public comment period was open 
for 20 days, and closed on April 11, 2011.

Policies for Delineating Species Under the ESA

    Section 3 of the ESA defines ``species'' as including ``any 
subspecies of fish or wildlife or plants, and any distinct population 
segment of any species of vertebrate fish or wildlife which interbreeds 
when mature.'' The term ``distinct population segment'' is not 
recognized in the scientific literature, nor clarified in the ESA or 
its implementing regulations. Therefore, the Services adopted a joint 
policy for recognizing DPSs under the ESA (DPS Policy; 61 FR 4722) on 
February 7, 1996. Congress has instructed the Secretary of the Interior 
or of Commerce to exercise this authority with regard to DPSs ``* * * 
sparingly and only when the biological evidence indicates such action 
is warranted.'' The DPS Policy requires the consideration of two 
elements when evaluating whether a vertebrate population segment 
qualifies as a 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.
    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 (an 
organism or group of organisms) as a consequence of physical, 
ecological, or behavioral factors. Quantitative measures of genetic or 
morphological discontinuity may provide evidence of this separation; or 
(2) it is delimited by international governmental boundaries within 
which differences in control of exploitation, management of habitat, 
conservation status, or regulatory mechanisms exist that are 
significant in light of section 4(a)(1)(D) of the ESA (i.e., inadequate 
regulatory mechanisms).
    If a population segment is found to be discrete under one or both 
of the above conditions, its biological and ecological significance to 
the taxon to which it belongs is evaluated. This consideration may 
include, but is not limited to: (1) Persistence of the discrete 
population segment in an ecological setting unusual or unique for the 
taxon; (2) evidence that loss of the discrete population segment would 
result in a significant gap in the range of a taxon; (3) evidence that 
the discrete population segment represents the only surviving natural 
occurrence of a taxon that may be more abundant elsewhere as an 
introduced population outside its historical range; or (4) evidence 
that the discrete population segment differs markedly from other 
population segments of the species in its genetic characteristics.

Listing Determinations Under the ESA

    The ESA defines an endangered species as one that is in danger of 
extinction throughout all or a significant portion of its range, and a 
threatened species as one that is likely to become endangered in the 
foreseeable future throughout all or a significant portion of its range 
(sections 3(6) and 3(20), respectively). The statute requires us to 
determine whether any species is endangered or threatened because of 
any of the following five factors: (1) The present or threatened 
destruction, modification, or curtailment of its habitat or range; (2) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (3) disease or predation; (4) the inadequacy of 
existing regulatory mechanisms; or (5) other natural or manmade factors 
affecting its continued existence (section 4(a)(1)(A-E)). We are to 
make this determination based solely on the best available scientific 
and commercial data after conducting a review of the status of the 
species and taking into account any efforts being made by States or 
foreign governments to protect the species.

Biology and Life History of Loggerhead Sea Turtles

    A thorough account of loggerhead sea turtle biology and life 
history may be found in the Status Review, which is incorporated here 
by reference. The following is a summary of that information.
    The loggerhead occurs throughout the temperate and tropical regions 
of the Atlantic, Pacific, and Indian Oceans (Dodd, 1988). However, the 
majority of loggerhead nesting is at the western rims of the Atlantic 
and Indian Oceans. The most recent reviews show that only two 
loggerhead nesting aggregations have greater than 10,000 females 
nesting per year: Peninsular Florida, United States, and Masirah 
Island, Oman (Baldwin et al., 2003; Ehrhart et al., 2003; Kamezaki et 
al., 2003; Limpus and Limpus, 2003a; Margaritoulis et al., 2003). 
Nesting aggregations with 1,000 to 9,999 females nesting annually are 
Georgia through North Carolina (United States), Quintana Roo and 
Yucatan (Mexico), Brazil, Cape Verde Islands (Cape Verde), Western 
Australia (Australia), and Japan. Smaller nesting aggregations with 100 
to 999 nesting females annually occur in the Northern Gulf of Mexico 
(United States), Dry Tortugas (United States), Cay Sal Bank (The 
Bahamas), Tongaland (South Africa), Mozambique, Arabian Sea Coast 
(Oman), Halaniyat Islands (Oman), Cyprus, Peloponnesus (Greece), 
Zakynthos (Greece), Crete (Greece), Turkey, and Queensland (Australia). 
In contrast to determining population size on nesting beaches, 
determining population size in the marine environment has been very 
localized. A summary of information on distribution and habitat by 
ocean basin follows.

Pacific Ocean

    Loggerheads can be found throughout tropical to temperate waters in 
the Pacific; however, their breeding grounds include a restricted 
number of sites in the North Pacific and South Pacific. Within the 
North Pacific, loggerhead nesting has been documented only in Japan 
(Kamezaki et al., 2003), although low level nesting may occur outside 
of Japan in areas surrounding the South China Sea (Chan et al., 2007). 
In the South Pacific, nesting beaches are restricted to eastern 
Australia and New Caledonia and, to a much lesser extent, Vanuatu and 
Tokelau (Limpus and Limpus, 2003a).
    Based on tag-recapture studies from Japan, the East China Sea has 
been identified as the major habitat for post-nesting adult females 
(Iwamoto et al., 1985; Kamezaki et al., 1997; Balazs, 2006), while 
satellite tracking indicates the Kuroshio Extension Bifurcation Region 
to be an important pelagic foraging area for juvenile loggerheads 
(Polovina et al., 2006). Other important juvenile turtle foraging areas 
have been identified off the coast of Baja California Sur, Mexico 
(Pitman, 1990; Peckham and Nichols, 2006; Peckham et al., 2007).
    Nesting females tagged on the coast of eastern Australia have been 
recorded

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foraging in New Caledonia; Queensland, northern New South Wales, and 
Northern Territory, Australia; Solomon Islands; Papua New Guinea; and 
Indonesia (Limpus and Limpus, 2003a; Limpus, 2009). Foraging Pacific 
loggerheads originating from nesting beaches in Australia are known to 
migrate to Chile and Peru (Alfaro-Shigueto et al., 2004, 2008a; Donoso 
and Dutton, 2006; Boyle et al., 2009).

Indian Ocean

    In the North Indian Ocean, Oman hosts the vast majority of 
loggerhead nesting. The majority of the nesting in Oman occurs on 
Masirah Island, on the Al Halaniyat Islands, and on mainland beaches 
south of Masirah Island all the way to the Oman-Yemen border (IUCN--The 
World Conservation Union, 1989a, 1989b; Salm, 1991; Salm and Salm, 
1991). In addition, nesting probably occurs on the mainland of Yemen on 
the Arabian Sea coast, and nesting has been confirmed on Socotra, an 
island off the coast of Yemen (Pilcher and Saad, 2000). Limited 
information exists on the foraging habitats of North Indian Ocean 
loggerheads; however, foraging individuals have been reported off the 
southern coastline of Oman (Salm et al., 1993). Satellite telemetry 
studies of post-nesting migrations of loggerheads nesting on Masirah 
Island, Oman, have revealed extensive use of the waters off the Arabian 
Peninsula, with the majority of telemetered turtles traveling 
southwest, following the shoreline of southern Oman and Yemen, and 
circling well offshore in nearby oceanic waters (Environment Society of 
Oman and Ministry of Environment and Climate Change, Oman, unpublished 
data). A minority traveled north as far as the western Persian Gulf or 
followed the shoreline of southern Oman and Yemen as far west as the 
Gulf of Aden and the Bab-el-Mandab.
    The only verified nesting beaches for loggerheads on the Indian 
subcontinent are found in Sri Lanka. A small number of nesting females 
use the beaches of Sri Lanka every year (Deraniyagala, 1939; Kar and 
Bhaskar, 1982; Dodd, 1988); however, there are no records indicating 
that Sri Lanka has ever been a major nesting area for loggerheads 
(Kapurusinghe, 2006). No confirmed nesting occurs on the mainland of 
India (Tripathy, 2005; Kapurusinghe, 2006). The Gulf of Mannar provides 
foraging habitat for juvenile and post-nesting adult turtles (Tripathy, 
2005; Kapurusinghe, 2006).
    In the East Indian Ocean, Western Australia hosts all known 
loggerhead nesting (Dodd, 1988). Nesting distributions in Western 
Australia span from the Shark Bay World Heritage Area, including Dirk 
Hartog Island, and northward through the Ningaloo Marine Park coast to 
the North West Cape, including the Muiron Islands (Baldwin et al., 
2003). Nesting individuals from Dirk Hartog Island have been recorded 
foraging within Shark Bay and Exmouth Gulf (Baldwin et al., 2003), and 
satellite tracking of individuals from Ningaloo has demonstrated that 
female turtles can disperse as far east as Torres Strait in Queensland.
    In the Southwest Indian Ocean, loggerhead nesting occurs on the 
southeastern coast of Africa, from the Paradise Islands in Mozambique 
southward to St. Lucia in South Africa, and on the south and 
southwestern coasts of Madagascar (Baldwin et al., 2003). Foraging 
habitats are only known for post-nesting females from Tongaland, South 
Africa; tagging data show these loggerheads migrating eastward to 
Madagascar, northward to Mozambique, Tanzania, and Kenya, and southward 
to Cape Agulhas at the southernmost point of Africa (Baldwin et al., 
2003; Luschi et al., 2006).

Atlantic Ocean

    In the Northwest Atlantic, the majority of loggerhead nesting is 
concentrated along the coasts of the United States from southern 
Virginia through Alabama. Additional nesting beaches are found along 
the northern and western Gulf of Mexico, eastern Yucatan Peninsula, at 
Cay Sal Bank in the eastern Bahamas (Addison and Morford, 1996; 
Addison, 1997), on the southwestern coast of Cuba (F. Moncada-Gavilan, 
personal communication, cited in Ehrhart et al., 2003), and along the 
coasts of Central America, Colombia, Venezuela, and the eastern 
Caribbean Islands. In the Southwest Atlantic, loggerheads nest in 
significant numbers only in Brazil. In the eastern Atlantic, the 
largest nesting population of loggerheads is in the Cape Verde Islands 
(L.F. L[oacute]pez-Jurado, personal communication, cited in Ehrhart et 
al., 2003), and some nesting occurs along the West African coast 
(Fretey, 2001).
    As post-hatchlings, Northwest Atlantic loggerheads use the North 
Atlantic Gyre and enter Northeast Atlantic waters (Carr, 1987). They 
are also found in the Mediterranean Sea (Carreras et al., 2006; Eckert 
et al., 2008). In these areas, they overlap with animals originating 
from the Northeast Atlantic and the Mediterranean Sea (Laurent et al., 
1993, 1998; Bolten et al., 1998; LaCasella et al., 2005; Carreras et 
al., 2006; Monz[oacute]n-Arg[uuml]ello et al., 2006, 2010; Revelles et 
al., 2007; Eckert et al., 2008). The oceanic juvenile stage in the 
North Atlantic has been primarily studied in the waters around the 
Azores and Madeira (Bolten, 2003). In Azorean waters, satellite 
telemetry data and flipper tag returns suggest a long period of 
residency (Bolten, 2003), whereas turtles appear to be moving through 
Madeiran waters (Dellinger and Freitas, 2000). Preliminary genetic 
analyses indicate that juvenile loggerheads found in Moroccan waters 
are of western Atlantic origin (M. Tiwari, NMFS, and A. Bolten, 
University of Florida, unpublished data). Other concentrations of 
oceanic juvenile turtles exist in the Atlantic (e.g., in the region of 
the Grand Banks off Newfoundland; Witzell, 2002). Genetic information 
indicates the Grand Banks are foraging grounds for a mixture of 
loggerheads from all the North Atlantic rookeries (Bowen et al., 2005; 
LaCasella et al., 2005), and a large size range is represented (Watson 
et al., 2004, 2005).
    After departing the oceanic zone, neritic juvenile loggerheads in 
the Northwest Atlantic inhabit continental shelf waters from Cape Cod 
Bay, Massachusetts, south through Florida, The Bahamas, Cuba, and the 
Gulf of Mexico (Musick and Limpus, 1997; Spotila et al., 1997; Hopkins-
Murphy et al., 2003) (neritic refers to the inshore marine environment 
from the surface to the sea floor where water depths do not exceed 200 
meters).
    Habitat preferences of Northwest Atlantic non-nesting adult 
loggerheads in the neritic zone differ from the juvenile stage in that 
relatively enclosed, shallow water estuarine habitats with limited 
ocean access are less frequently used. Areas such as Pamlico Sound, 
North Carolina, and the Indian River Lagoon, Florida, in the United 
States, regularly used by juvenile loggerheads, are only rarely 
frequented by adults (Ehrhart and Redfoot, 1995; Epperly et al., 2007). 
In comparison, estuarine areas with more open ocean access, such as the 
Chesapeake Bay in the U.S. mid-Atlantic, are also regularly used by 
juvenile loggerheads, as well as by adults primarily during warmer 
seasons (J. Musick, The Virginia Institute of Marine Science, personal 
communication, 2008). Shallow water habitats with large expanses of 
open ocean access, such as Florida Bay, provide year-round resident 
foraging areas for significant numbers of male and female adult 
loggerheads (Schroeder et al., 1998; Witherington et al., 2006a). 
Offshore, adults inhabit continental shelf waters, from New York south 
through Florida, The Bahamas, Cuba, and the Gulf of Mexico (Schroeder 
et al., 2003; Hawkes et al.,

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2007; Foley et al., 2008). The southern edge of the Grand Bahama Bank 
is important habitat for loggerheads nesting on the Cay Sal Bank in The 
Bahamas, but nesting females are also resident in the bights of 
Eleuthera, Long Island, and Ragged Islands as well as Florida Bay in 
the United States, and the north coast of Cuba (A. Bolten and K. 
Bjorndal, University of Florida, unpublished data). Moncada et al. 
(2010) reported the recapture in Cuban waters of five adult female 
loggerheads originally flipper tagged in Quintana Roo, Mexico, 
indicating that Cuban shelf waters likely also provide foraging habitat 
for adult females that nest in Mexico.
    In the Northeast Atlantic, satellite telemetry studies of post-
nesting females from Cape Verde identified two distinct dispersal 
patterns; larger individuals migrated to benthic foraging areas off the 
northwest Africa coast and smaller individuals foraged primarily 
oceanically off the northwest Africa coast (Hawkes et al., 2006). 
Monz[oacute]n-Arg[uuml]ello et al. (2009) conducted a mixed stock 
analysis of juvenile loggerheads sampled from foraging areas in the 
Canary Islands, Madeira, Azores, and Andalusia and concluded that while 
juvenile loggerheads from the Cape Verde population were distributed 
among these four sites, a large proportion of Cape Verde juvenile 
turtles appear to inhabit as yet unidentified foraging areas.
    In the South Atlantic, recaptures of tagged juvenile turtles and 
nesting females have shown movement of animals up and down the coast of 
South America (Almeida et al., 2000, 2007; Marcovaldi et al., 2000; 
Laporta and Lopez, 2003). Juvenile loggerheads, presumably of Brazilian 
origin, have also been captured on the high seas of the South Atlantic 
(Kotas et al., 2004; Pinedo and Polacheck, 2004) and off the coast of 
Atlantic Africa (Petersen, 2005; Bal et al., 2007; Petersen et al., 
2007) suggesting that loggerheads of the South Atlantic may undertake 
transoceanic developmental migrations (Bolten et al., 1998; Peckham et 
al., 2007). Marcovaldi et al. (2010) identified the northeastern coast 
of Brazil as important foraging habitat for post-nesting females from 
Bahia, Brazil.

Mediterranean Sea

    Loggerhead sea turtles are widely distributed in the Mediterranean 
Sea. However, nesting is almost entirely confined to the eastern 
Mediterranean basin, with the main nesting concentrations in Cyprus, 
Greece, and Turkey (Margaritoulis et al., 2003; Casale and 
Margaritoulis, 2010). Preliminary surveys in Libya suggested nesting 
activity comparable to Greece and Turkey, although a better 
quantification is needed (Laurent et al., 1999). Minimal to moderate 
nesting also occurs in other countries throughout the Mediterranean 
including Egypt, Israel, Italy (southern coasts and islands), Lebanon, 
Syria, and Tunisia (Margaritoulis et al., 2003). Recently, isolated 
nesting events have been recorded in the western Mediterranean basin, 
namely in Spain, Corsica (France), and in the Tyrrhenian Sea (Italy) 
(Tom[aacute]s et al., 2002; Delaugerre and Cesarini, 2004; Bentivegna 
et al., 2005).
    Important neritic habitats have been suggested for the large 
continental shelves of: (1) Tunisia-Libya, (2) northern Adriatic Sea, 
(3) Egypt, and (4) Spain (Margaritoulis, 1988; Argano et al., 1992; 
Laurent and Lescure, 1994; Lazar et al., 2000; Gomez de Segura et al., 
2006; Broderick et al., 2007; Casale et al., 2007a; Nada and Casale, 
2008). At least the first three constitute shallow benthic habitats for 
adults (including post-nesting females). Some other neritic foraging 
areas include Amvrakikos Bay in western Greece, Lakonikos Bay in 
southern Greece, and southern Turkey. Oceanic foraging areas for small 
juvenile loggerheads have been identified in the south Adriatic Sea 
(Casale et al., 2005a), Ionian Sea (Deflorio et al., 2005), Sicily 
Strait (Casale et al., 2007a), and western Mediterranean (Spain) (e.g., 
Cami[ntilde]as et al., 2006). In addition, tagged juvenile loggerheads 
have been recorded crossing the Mediterranean from the eastern to the 
western basin and vice versa, as well as in the Eastern Atlantic 
(Argano et al., 1992; Casale et al., 2007a).
    Reproductive migrations have been confirmed by flipper tagging and 
satellite telemetry. Female loggerheads, after nesting in Greece, 
migrate primarily to the Gulf of Gab[egrave]s and the northern Adriatic 
(Margaritoulis, 1988; Margaritoulis et al., 2003; Lazar et al., 2004; 
Zbinden et al., 2008). Loggerheads nesting in Cyprus migrate to Egypt 
and Libya, exhibiting fidelity in following the same migration route 
during subsequent nesting seasons (Broderick et al., 2007). In 
addition, directed movements of juvenile loggerheads have been 
confirmed through flipper tagging (Argano et al., 1992; Casale et al., 
2007a) and satellite tracking (Rees and Margaritoulis, 2009).

Overview of Information Used To Identify DPSs

    In the Status Review, the BRT considered a vast array of 
information to assess whether there were any loggerhead population 
segments that satisfy the DPS criteria of both discreteness and 
significance. First, the BRT examined whether there were any loggerhead 
population segments that were discrete. Data relevant to the 
discreteness question included physical, ecological, behavioral, and 
genetic data. Given the physical separation of ocean basins by 
continents, the BRT evaluated these data by ocean basin (Pacific Ocean, 
Indian Ocean, and Atlantic Ocean). This was not to preclude any larger 
or smaller DPS delineation, but to aid in data organization and 
assessment. The BRT then evaluated genetic information by ocean basin. 
The genetic data consisted of results from studies using maternally 
inherited mitochondrial DNA (mtDNA) and biparentally inherited nuclear 
DNA microsatellite markers. Next, tagging data (both flipper and 
Passive Integrated Transponder (PIT) tags) and telemetry data were 
reviewed. Additional information, such as potential differences in 
morphology, was also evaluated. Finally, the BRT considered whether the 
available information on loggerhead population segments was bounded by 
any oceanographic features (e.g., current systems) or geographic 
features (e.g., land masses).
    In accordance with the DPS policy, the BRT also reviewed whether 
the population segments identified in the discreteness analysis were 
significant. If a population segment is considered discrete, its 
biological and ecological significance relative to the species or 
subspecies must then be considered. NMFS and USFWS must consider 
available scientific evidence of the discrete segment's importance to 
the taxon to which it belongs. Data relevant to the significance 
question include morphological, ecological, behavioral, and genetic 
data, as described above. The BRT considered the following factors, 
listed in the DPS policy, in determining whether the discrete 
population segments were significant: (a) Persistence of the discrete 
segment in an ecological setting unusual or unique for the taxon; (b) 
evidence that loss of the discrete segment would result in a 
significant gap in the range of the taxon; (c) evidence that the 
discrete segment represents the only surviving natural occurrence of a 
taxon that may be more abundant elsewhere as an introduced population 
outside its historical range; and (d) evidence that the discrete 
segment differs markedly from other populations of the species in its 
genetic characteristics. A discrete population segment needs to satisfy 
only one of

[[Page 58872]]

these criteria to be considered significant. As described below, the 
BRT evaluated the available information and considered items (a), (b), 
and (d), as noted above, to be most applicable to loggerheads.

Discreteness Determination

    As described in the Status Review, the loggerhead sea turtle is 
present in all tropical and temperate ocean basins, and has a life 
history that involves nesting on coastal beaches and foraging in 
neritic and oceanic habitats, as well as long-distance migrations 
between and within these areas. As with other globally distributed 
marine species, today's global loggerhead distribution has been shaped 
by a sequence of isolation events created by tectonic and oceanographic 
shifts over geologic time scales, the result of which is population 
substructuring in many areas (Bowen et al., 1994; Bowen, 2003). 
Globally, loggerhead sea turtles comprise a mosaic of populations, each 
with unique nesting sites and in many cases possessing disparate 
demographic features (e.g., mean body size, age at first reproduction) 
(Dodd, 1988). However, despite these differences, loggerheads from 
different nesting populations often mix in common foraging areas during 
certain life stages (Bolten and Witherington, 2003; Bowen and Karl, 
2007), thus creating unique challenges when attempting to delineate 
distinct population segments for management or listing purposes.
    Bowen et al. (1994) examined the mtDNA sequence diversity of 
loggerheads across their global distribution and found a separation of 
loggerheads in the Atlantic-Mediterranean basins from those in the 
Indo-Pacific basins since the Pleistocene period. The divergence 
between these two primary lineages corresponds to approximately three 
million years (2 percent divergence per million years; Dutton et al., 
1996; Encalada et al., 1996). Geography and climate appear to have 
shaped the evolution of these two matriarchal lineages with the onset 
of glacial cycles, the appearance of the Panama Isthmus creating a land 
barrier between the Atlantic and eastern Pacific, and upwelling of cold 
water off southern Africa creating an oceanographic barrier between the 
Atlantic and Indian Oceans (Bowen, 2003). Recent warm temperatures 
during interglacial periods allowed bi-directional invasion by the 
temperate-adapted loggerheads into the respective basins (Bowen et al., 
1994; J.S. Reece, Washington University, personal communication, 2008). 
Today, it appears that loggerheads within a basin are effectively 
isolated from populations in the other basin, but some dispersal from 
the Tongaland rookery in the Indian Ocean into feeding and 
developmental habitat in the South Atlantic is possible via the Agulhas 
Current (G.R. Hughes, unpublished data, cited in Bowen et al., 1994). 
In the Pacific, extensive mtDNA studies show that the northern 
loggerhead populations are isolated from the southern Pacific 
populations, and that juvenile loggerheads from these distinct genetic 
populations do not disperse across the equator (Bowen et al., 1994, 
1995; Hatase et al., 2002a; Dutton, 2007, unpublished data; Boyle et 
al., 2009).
    Mitochondrial DNA data indicate that regional turtle rookeries 
within an ocean basin have been strongly isolated from one another over 
ecological timescales (Bowen et al., 1994; Bowen and Karl, 2007). These 
same data indicate strong female natal homing and suggest that each 
regional nesting population is an independent demographic unit (Bowen 
et al., 2004, 2005; Bowen and Karl, 2007). It is difficult to determine 
the precise boundaries of these demographically independent populations 
in regions, such as the eastern U.S. coast, where rookeries are close 
to each other and range along large areas of a continental coastline. 
There appear to be varying levels of connectivity between proximate 
rookeries facilitated by imprecise natal homing and male mediated gene 
flow (Pearce, 2001; Bowen, 2003; Bowen et al., 2005). Regional genetic 
populations often are characterized by allelic frequency differences 
rather than fixed genetic differences (Bowen and Karl, 2007).
    Through the evaluation of genetic data, tagging data, telemetry, 
and demography, the BRT determined that there are at least nine 
discrete population segments of loggerhead sea turtles globally. These 
discrete population segments are markedly separated from each other as 
a consequence of physical, ecological, behavioral, and oceanographic 
factors and, given the genetic evidence, the BRT concluded that each 
regional population identified is discrete from other populations of 
loggerheads. Information considered by the BRT in its delineation of 
discrete population segments is presented below by ocean basin.

Pacific Ocean

    In the North Pacific Ocean, the primary loggerhead nesting areas 
are found along the southern Japanese coastline and Ryukyu Archipelago 
(Kamezaki et al., 2003), although low level nesting may occur outside 
Japan in areas surrounding the South China Sea (Chan et al., 2007). 
Loggerhead sea turtles hatching on Japanese beaches undertake extensive 
developmental migrations using the Kuroshio and North Pacific Currents 
(Balazs, 2006; Kobayashi et al., 2008), and some turtles reach the 
vicinity of Baja California in the eastern Pacific (Uchida and Teruya, 
1988; Bowen et al., 1995; Peckham et al., 2007). After spending years 
foraging in the central and eastern Pacific, loggerheads return to 
their natal beaches for reproduction (Resendiz et al., 1998; Nichols et 
al., 2000) and remain in the western Pacific for the remainder of their 
life cycle (Iwamoto et al., 1985; Kamezaki et al., 1997; Sakamoto et 
al., 1997; Hatase et al., 2002c).
    Despite these long-distance developmental movements of juvenile 
loggerheads in the North Pacific, current scientific evidence, based on 
genetic analysis, flipper tag recoveries, and satellite telemetry, 
indicates that individuals originating from Japan remain in the North 
Pacific for their entire life cycle, never crossing the equator or 
mixing with individuals from the South Pacific (Bowen et al., 1995; 
Hatase et al., 2002a; LeRoux and Dutton, 2006; Dutton, 2007, 
unpublished data; Boyle et al., 2009). This apparent, almost complete 
separation of two adjacent populations most likely results from: (1) 
The presence of two distinct Northern and Southern Gyre (current flow) 
systems in the Pacific (Briggs, 1974), (2) near-passive movements of 
post-hatchlings in these gyres that initially move them farther away 
from areas of potential mixing among the two populations along the 
equator, and (3) the nest-site fidelity of adult turtles that prevents 
turtles from returning to non-natal nesting areas.
    Pacific loggerheads are further partitioned evolutionarily from 
other loggerheads throughout the world based on additional analyses of 
mtDNA. The haplotypes (a haplotype refers to the genetic signature, 
coded in mtDNA, of an individual) from both North and South Pacific 
loggerheads are distinguished by a minimum genetic distance (d) equal 
to 0.017 from other conspecifics, which indicates isolation of 
approximately one million years (Bowen, 2003).
    Within the Pacific, Bowen et al. (1995) used mtDNA to identify two 
genetically distinct nesting populations in the Pacific--a northern 
hemisphere population nesting in Japan and a southern hemisphere 
population nesting primarily in Australia. This study also suggested 
that some loggerheads sampled as bycatch in the North Pacific

[[Page 58873]]

might be from the Australian nesting population (Bowen et al., 1995). 
However, more extensive mtDNA data from rookeries in Japan (Hatase et 
al., 2002a) taken together with preliminary results from microsatellite 
(nuclear) analysis confirms that loggerheads inhabiting the North 
Pacific actually originate from nesting beaches in Japan (Watanabe et 
al., 2011; P. Dutton, NMFS, unpublished data).
    Although these studies indicate genetic distinctness between 
loggerheads nesting in Japan versus those nesting in Australia, Bowen 
et al. (1995) did identify individuals with the common Australian 
haplotype at foraging areas in the North Pacific, based on a few 
individuals sampled as bycatch in the North Pacific. Bowen et al. 
(1995) indicated that this finding could be an artifact of sampling 
variance or that the Australian haplotype exists at low frequency in 
Japanese nesting aggregates but escaped detection in their study. More 
recently, Hatase et al. (2002a) and Watanabe et al. (2011) detected 
this common Australian haplotype at very low frequency at Japanese 
nesting beaches. However, the presence of the common Australian 
haplotype does not preclude the genetic distinctiveness of Japanese and 
Australian nesting populations, and is likely the result of rare gene 
flow events occurring over geologic time scales. Watanabe et al. (2011) 
found sub-structuring among the Japanese nesting sites based on mtDNA 
results, but homogeneity of nuclear DNA variation among the same 
Japanese nesting sites, indicating connectivity through male-mediated 
gene flow. These results taken together are consistent with the 
previous evidence supporting the genetic distinctiveness of the 
northern (Japanese) stocks from the southern Pacific nesting stocks.
    The discrete status of loggerheads in the North Pacific is further 
supported by results from flipper tagging in the North Pacific. Flipper 
tagging of loggerheads has been widespread throughout this region, 
occurring on adults nesting in Japan and bycaught in the coastal pound 
net fishery (Y. Matsuzawa, Sea Turtle Association of Japan, personal 
communication, 2006), juvenile turtles reared and released in Japan 
(Uchida and Teruya, 1988; Hatase et al., 2002a), juvenile turtles 
foraging near Baja California, Mexico (Nichols, 2003; Seminoff et al., 
2004), and juvenile and adult loggerheads captured in and tagged from 
commercial fisheries platforms in the North Pacific high seas (NMFS, 
unpublished data). To date, there have been at least three trans-
Pacific tag recoveries showing east-west and west-east movements 
(Uchida and Teruya, 1988; Resendiz et al., 1998; W.J. Nichols, 
California Academy of Sciences, and H. Peckham, Pro Peninsula, 
unpublished data) and several recoveries of adults in the western 
Pacific (Iwamoto et al., 1985; Kamezaki et al., 1997). Tag returns show 
post-nesting females migrating into the East China Sea off South Korea, 
China, and the Philippines, and the nearby coastal waters of Japan 
(Iwamoto et al., 1985; Kamezaki et al., 1997, 2003). However, despite 
the more than 30,000 marked individuals, not a single tag recovery has 
been reported outside the North Pacific.
    A lack of movements by loggerheads south across the equator has 
also been supported by extensive satellite telemetry. As with flipper 
tagging, satellite telemetry has been conducted widely in the North 
Pacific, with satellite transmitters being placed on adult turtles 
departing nesting beaches (Sakamoto et al., 1997; Japan Fisheries 
Resource Conservation Association, 1999; Hatase et al., 2002b, 2002c), 
on adult and juvenile turtles bycaught in pound nets off the coast of 
Japan (Sea Turtle Association of Japan, unpublished data), on captive-
reared juvenile turtles released in Japan (Balazs, 2006), on juvenile 
and adult turtles bycaught in the eastern and central North Pacific 
(e.g., Kobayashi et al., 2008; Peckham, 2008), and on juvenile turtles 
foraging in the eastern Pacific (Nichols et al., 2000; Nichols, 2003; 
Peckham et al., 2007; Peckham, 2008; J. Seminoff, NMFS, unpublished 
data). Aerial surveys and satellite telemetry studies, which have 
documented juvenile foraging areas in the eastern Pacific, near Baja 
California, Mexico (Nichols, 2003; Seminoff et al., 2006; Peckham et 
al., 2007; H. Peckham, Pro Peninsula, unpublished data) and Peru 
(Mangel et al., in press), similarly showed a complete lack of long 
distance north or south movements. Of the nearly 200 loggerheads 
tracked using satellite telemetry in the North Pacific, none have moved 
south of the equator.
    Studies have demonstrated the strong association loggerheads show 
with oceanographic mesoscale features such as the Kuroshio Current 
Bifurcation Region and the Transition Zone Chlorophyll Front (Polovina 
et al., 2000, 2001, 2004, 2006; Etnoyer et al., 2006; Kobayashi et al., 
2008). The Kuroshio Extension Current, lying west of the international 
date line, serves as the dominant physical and biological habitat in 
the North Pacific and is highly productive, likely due to unique 
features such as eddies and meanders that concentrate prey and support 
food webs. Juvenile loggerheads originating from nesting beaches in 
Japan exhibit high site fidelity to this area referred to as the 
Kuroshio Extension Bifurcation Region (Polovina et al., 2006). Juvenile 
turtles also were found to correlate strongly with the Transition Zone 
Chlorophyll Front, an area of surface chlorophyll a levels that also 
concentrates surface prey for loggerheads (Polovina et al., 2001; 
Parker et al., 2005; Kobayashi et al., 2008). Kobayashi et al. (2008) 
demonstrated that loggerheads strongly track these zones even as they 
shift in location, suggesting that strong habitat specificity during 
the oceanic stage also contributes to the lack of mixing. In summary, 
loggerheads inhabiting the North Pacific Ocean are derived primarily, 
if not entirely, from Japanese beaches, with the possible exception of 
rare waifs over evolutionary time scales. Further, nesting colonies of 
Japanese loggerheads are found to be genetically distinct based on 
mtDNA analyses, and when compared to much larger and more genetically 
diverse loggerhead populations in the Atlantic and Mediterranean, 
Pacific loggerheads have likely experienced critical bottlenecks (in 
Hatase et al., 2002a). This is the only known population of loggerheads 
to be found north of the equator in the Pacific Ocean, foraging in the 
eastern Pacific as far south as Baja California Sur, Mexico (Seminoff 
et al., 2004; Peckham et al., 2007) and in the western Pacific as far 
south as the Philippines (Limpus, 2009) and the mouth of Mekong River, 
Vietnam (Sadoyama et al., 1996; Hamann et al., 2006).
    In the South Pacific Ocean, loggerhead sea turtles nest primarily 
in Queensland, Australia, and, to a lesser extent, New Caledonia and 
Vanuatu (Limpus and Limpus, 2003a; Limpus et al., 2006; Limpus, 2009). 
Loggerheads from these rookeries undertake an oceanic developmental 
migration, traveling to habitats in the central and southeastern 
Pacific Ocean where they may reside for several years prior to 
returning to the western Pacific for reproduction. Loggerheads in this 
early life history stage differ markedly from those originating from 
Western Australia beaches in that they undertake long west-to-east 
migrations, likely using specific areas of the pelagic environment of 
the South Pacific Ocean. An unknown portion of these loggerheads forage 
off Chile and Peru, and genetic information from foraging areas in the 
southeastern Pacific confirms that the haplotype frequencies among 
juvenile turtles in these areas closely match those found at nesting

[[Page 58874]]

beaches in eastern Australia (Alfaro-Shigueto et al., 2004; Donoso and 
Dutton, 2006, 2007; Boyle et al., 2009). Large juvenile and adult 
loggerheads generally remain in the western South Pacific, inhabiting 
neritic and oceanic foraging sites during non-nesting periods (Limpus 
et al., 1994; Limpus, 2009).
    Loggerheads from Australia and New Caledonia apparently do not 
travel north of the equator. Flipper tag recoveries from nesting 
females have been found throughout the western Pacific, including the 
southern Great Barrier Reef and Moreton Bay off the coast of 
Queensland, Australia, Indonesia (Irian Jaya), Papua New Guinea, 
Solomon Islands, the Torres Strait, and the Gulf of Carpentaria 
(Limpus, 2009). Of approximately 1,000 (adult and juvenile; male and 
female) loggerheads that have been tagged in eastern Australian feeding 
areas over approximately 25 years, only two have been recorded nesting 
outside of Australia; both traveled to New Caledonia (Limpus and 
Limpus, 2003b; Limpus, 2009). Flipper tagging programs in Peru and 
Chile tagged approximately 500 loggerheads from 1999 to 2006, none of 
which have been reported from outside of the southeastern Pacific 
(Alfaro-Shigueto et al., 2008a; S. Kelez, Duke University Marine 
Laboratory, unpublished data; M. Donoso, ONG Pacifico Laud--Chile, 
unpublished data). Limited satellite telemetry data from 12 turtles in 
the southeastern Pacific area show a similar trend (Mangel et al., in 
press).
    The spatial separation between the North Pacific and South Pacific 
loggerhead populations has contributed to substantial differences in 
the genetic profiles of the nesting populations in these two regions. 
Whereas the dominant mtDNA haplotypes among loggerheads nesting in 
Japan are CCP2 and CCP3 (equivalent to B and C respectively in Bowen et 
al., 1995 and Hatase et al., 2002a; LeRoux et al., 2008; P. Dutton, 
NMFS, unpublished data), loggerheads nesting in eastern Australia have 
a third haplotype (CCP1, previously A) which is dominant (98 percent of 
nesting females) (Bowen et al., 1994; FitzSimmons et al., 1996; Boyle 
et al., 2009). Further, preliminary genetic analysis using 
microsatellite markers (nuclear DNA) indicates genetic distinctiveness 
between nesting populations in the North versus South Pacific (P. 
Dutton, NMFS, personal communication, 2008).
    The separateness between nesting populations in eastern Australia 
(in the South Pacific Ocean) and western Australia (in the East Indian 
Ocean) is less clear, although these too are considered to be 
genetically distinct from one another (Limpus, 2009). For example, 
mtDNA haplotype CCP1, which is the overwhelmingly dominant haplotype 
among eastern Australia nesting females (98 percent), is also found in 
western Australia, although at much lower frequency (33 percent) 
(FitzSimmons et al., 1996, 2003). The remaining haplotype for both 
regions was the CCP5 haplotype. Further, FitzSimmons (University of 
Canberra, unpublished data) found significant differences in nuclear 
DNA microsatellite loci from females nesting in these two regions. 
Estimates of gene flow between eastern and western Australian 
populations were an order of magnitude less than gene flow within 
regions. These preliminary results based on nuclear DNA indicate that 
male-mediated gene flow between eastern and western Australia may be 
insignificant, which, when considered in light of the substantial 
disparity in mtDNA haplotype frequencies between these two regions, 
provides further evidence of population separation. It is also 
important to note that there is no nesting by loggerheads recorded by 
either scientists or indigenous peoples for the thousands of kilometers 
of sandy beaches between the rookeries of Queensland and Western 
Australia (Chatto and Baker, 2008).
    At present, there is no indication from genetic studies that the 
loggerhead sea turtles nesting in eastern Australia are distinct from 
those nesting in New Caledonia. Of 27 turtles sequenced from New 
Caledonia, 93 percent carried the CCP1 haplotype and the remaining had 
the CCP5 haplotype; similar to eastern Australia (Boyle et al., 2009).
    The South Pacific population of loggerheads occupies an ecological 
setting distinct from other loggerheads, including the North Pacific 
population; however, less is known about the ecosystem on which South 
Pacific oceanic juvenile and adult loggerheads depend. Sea surface 
temperature and chlorophyll frontal zones in the South Pacific have 
been shown to dramatically affect the movements of green turtles, 
Chelonia mydas (Seminoff et al., 2008) and leatherback turtles, 
Dermochelys coriacea (Shillinger et al., 2008), and it is likely that 
loggerhead distributions are also affected by these mesoscale 
oceanographic features. However, unlike the North Pacific, there are no 
records of oceanic aggregations of loggerhead sea turtles.
    Loggerheads in the South Pacific are substantially impacted by 
periodic environmental perturbations such as the El Ni[ntilde]o 
Southern Oscillation (ENSO). This 3- to 6-year cycle within the coupled 
ocean-atmosphere system of the tropical Pacific brings increased 
surface water temperatures and lower primary productivity, both of 
which have profound biological consequences (Chavez et al., 1999; Saba 
et al., 2008). Loggerheads are presumably adversely impacted by the 
reduced food availability that often results from ENSO events, although 
data on this subject are lacking. Although ENSO may last for only short 
periods and thus not have a long-term effect on loggerheads in the 
region, recent studies by Chaloupka et al. (2008) suggested that long-
term increases in sea surface temperature within the South Pacific may 
influence the ability of the Australian nesting population to recover 
from historical population declines.
    Loggerheads originating from nesting beaches in the western South 
Pacific are the only population of loggerheads to be found south of the 
equator in the Pacific Ocean. As post-hatchlings, they are generally 
swept south by the East Australian Current (Limpus et al., 1994), spend 
a large portion of time foraging in the oceanic South Pacific Ocean, 
and some migrate to the southeastern Pacific Ocean off the coasts of 
Peru and Chile as juvenile turtles (Donoso et al., 2000; Alfaro-
Shigueto et al., 2004, 2008a; Boyle et al., 2009). As large juveniles 
and adults, the foraging range of these loggerheads encompasses the 
eastern Arafura Sea, Gulf of Carpentaria, Torres Strait, Gulf of Papua, 
Coral Sea, and throughout the eastern coastline of Australia from north 
Queensland south to southern New South Wales, including the Great 
Barrier Reef, Hervey Bay, and Moreton Bay. The outer extent of this 
range includes the coastal waters off eastern Indonesia, northeastern 
Papua New Guinea, northeastern Solomon Islands, and New Caledonia 
(Limpus, 2009).
    In summary, all loggerheads inhabiting the South Pacific Ocean are 
derived from beaches in eastern Australia and a lesser known number of 
beaches in southern New Caledonia, Vanuatu, and Tokelau (Limpus and 
Limpus, 2003a; Limpus, 2009). Furthermore, nesting colonies of the 
South Pacific population of loggerheads are found to be genetically 
distinct from loggerheads in the North Pacific and Indian Ocean.
    Given the information presented above, the BRT concluded, and we 
concur, that two discrete population segments exist in the Pacific 
Ocean: (1) North Pacific Ocean and (2) South Pacific Ocean. These two 
population segments are markedly separated from each other and from 
population

[[Page 58875]]

segments within the Indian Ocean and Atlantic Ocean basins as a 
consequence of physical, ecological, behavioral, and oceanographic 
factors. Information supporting this conclusion includes genetic 
analysis, flipper tag recoveries, and satellite telemetry, which 
indicate that individuals originating from Japan remain in the North 
Pacific for their entire life cycle, likely never crossing the equator 
or mixing with individuals from the South Pacific (Bowen et al., 1995; 
Hatase et al., 2002a; LeRoux and Dutton, 2006; Dutton, 2007, 
unpublished data; Boyle et al., 2009). This apparent, almost complete 
separation most likely results from: (1) The presence of two distinct 
Northern and Southern Gyre (current flow) systems in the Pacific 
(Briggs, 1974), (2) near-passive movements of post-hatchlings in these 
gyres that initially move them farther away from areas of potential 
mixing along the equator, and (3) the nest-site fidelity of adult 
turtles that prevents turtles from returning to non-natal nesting 
areas. The separation of the Pacific Ocean population segments from 
population segments within the Indian Ocean and Atlantic Ocean basins 
is believed to be the result of land barriers and oceanographic 
barriers. Based on mtDNA analysis, Bowen et al. (1994) found a 
separation of loggerheads in the Atlantic-Mediterranean basins from 
those in the Indo-Pacific basins since the Pleistocene period. 
Geography and climate appear to have shaped the evolution of these two 
matriarchal lineages with the onset of glacial cycles, the appearance 
of the Panama Isthmus creating a land barrier between the Atlantic and 
eastern Pacific, and upwelling of cold water off southern Africa 
creating an oceanographic barrier between the Atlantic and Indian 
Oceans (Bowen, 2003).

Indian Ocean

    Similar to loggerheads in the Pacific and Atlantic, loggerheads in 
the Indian Ocean nest on coastal beaches, forage in neritic and oceanic 
habitats, and undertake long-distance migrations between and within 
these areas. The distribution of loggerheads in the Indian Ocean is 
limited by the Asian landmass to the north (approximately 30[deg] N. 
lat.); distributions east and west are not restricted by landmasses 
south of approximately 38[deg] S. latitude.
    In the North Indian Ocean, Oman hosts the vast majority of 
loggerhead nesting. The largest nesting assemblage is at Masirah 
Island, Oman, in the northern tropics at 21[deg] N. lat. (Baldwin et 
al., 2003). Other key nesting assemblages occur on the Al Halaniyat 
Islands, Oman (17[deg] S. lat.) and on Oman's Persian Gulf mainland 
beaches south of Masirah Island to the Oman-Yemen border (17-20[deg] S. 
lat.) (IUCN--The World Conservation Union, 1989a, 1989b; Salm, 1991; 
Salm and Salm, 1991; Baldwin et al., 2003). In addition, nesting 
probably occurs on the mainland of Yemen on the Arabian Sea coast, and 
nesting has been confirmed on Socotra, an island off the coast of Yemen 
(Pilcher and Saad, 2000).
    Outside of Oman, loggerhead nesting is rare in the North Indian 
Ocean. The only verified nesting beaches for loggerheads on the Indian 
subcontinent are found in Sri Lanka (Deraniyagala, 1939; Kar and 
Bhaskar, 1982; Dodd, 1988; Kapurusinghe, 2006). Reports of regular 
loggerhead nesting on the Indian mainland are likely misidentifications 
of olive ridleys (Lepidochelys olivacea) (Tripathy, 2005; Kapurusinghe, 
2006). Although loggerheads have been reported nesting in low numbers 
in Myanmar, these data may not be reliable because of misidentification 
of species (Thorbjarnarson et al., 2000).
    Limited information exists on foraging locations of North Indian 
Ocean loggerheads. Foraging individuals have been reported off the 
southern coastline of Oman (Salm et al., 1993) and in the Gulf of 
Mannar, between Sri Lanka and India (Tripathy, 2005; Kapurusinghe, 
2006). Satellite telemetry studies of post-nesting migrations of 
loggerheads nesting on Masirah Island, Oman, have revealed extensive 
use of the waters off the Arabian Peninsula, with the majority of 
telemetered turtles (15 of 20) traveling southwest, following the 
shoreline of southern Oman and Yemen, and circling well offshore in 
nearby oceanic waters (Environment Society of Oman and Ministry of 
Environment and Climate Change, Oman, unpublished data). A minority 
traveled north as far as the western Persian Gulf (3 of 20) or followed 
the shoreline of southern Oman and Yemen as far west as the Gulf of 
Aden and the Bab-el-Mandab (2 of 20). These preliminary data from Oman 
suggest that post-nesting migrations and adult female foraging areas 
are restricted to the Northwest Indian Ocean (Environment Society of 
Oman and Ministry of Environment and Climate Change, Oman, unpublished 
data). No tag returns or satellite tracks indicated that loggerheads 
nesting in Oman traveled south of the equator.
    In the East Indian Ocean, Western Australia hosts all known 
loggerhead nesting (Dodd, 1988). Nesting distributions in Western 
Australia span from the Shark Bay World Heritage Area northward through 
the Ningaloo Marine Park coast to the North West Cape and to the nearby 
Muiron Islands (Baldwin et al., 2003). Nesting individuals from Dirk 
Hartog Island have been recorded foraging within Shark Bay and Exmouth 
Gulf, while other adults range into the Gulf of Carpentaria (Baldwin et 
al., 2003) as far east as Torres Strait. At the eastern extent of this 
apparent range, there is likely overlap with loggerheads that nest on 
Australia's Pacific coast (Limpus, 2009). However, despite extensive 
tagging and beach monitoring at principal nesting beaches on 
Australia's Indian Ocean and Pacific coasts, no exchange of females 
between nesting beaches has been observed (Limpus, 2009).
    Loggerhead nesting in the Southwest Indian Ocean includes the 
southeastern coast of Africa from the Paradise Islands in Mozambique 
southward to St. Lucia in South Africa, and on the south and 
southwestern coasts of Madagascar (Baldwin et al., 2003). Foraging 
habitats are only known for the Tongaland, South Africa, adult female 
loggerheads. Returns of flipper tags describe a range that extends 
eastward to Madagascar, northward to Mozambique, Tanzania, and Kenya, 
and southward to Cape Agulhas at the southernmost point of Africa 
(Baldwin et al., 2003). Four post-nesting loggerheads satellite tracked 
by Luschi et al. (2006) migrated northward, hugging the Mozambique 
coast and remained in shallow shelf waters off Mozambique for more than 
2 months. Only one post-nesting female from the Southwest Indian Ocean 
population (South Africa) has been documented migrating north of the 
equator (to southern Somalia) (Hughes and Bartholomew, 1996).
    The available genetic information relates to connectivity and broad 
evolutionary relationships between ocean basins. There is a lack of 
genetic information on population structure among rookeries within the 
Indian Ocean. Bowen et al. (1994) described mtDNA sequence diversity 
among eight loggerhead nesting assemblages and found one of two 
principal branches in the Indo-Pacific basins. Using additional 
published and unpublished data, Bowen (2003) estimated divergence 
between these two lineages to be approximately three million years. 
Bowen pointed out evidence for more recent colonizations (12,000-
250,000 years ago) between the Indian Ocean and the Atlantic-
Mediterranean. For example, the sole mtDNA haplotype (among eight 
samples) identified by Bowen et al. (1994) at Masirah Island, Oman, is 
known from the Atlantic and suggests some exchange between oceans some 
250,000 years ago. The other principal Indian Ocean haplotype reported 
by

[[Page 58876]]

Bowen et al. (1994) was seen in all loggerheads sampled (n = 15) from 
Natal, South Africa. Encalada et al. (1998) reported that this 
haplotype was common throughout the North Atlantic and Mediterranean, 
thus suggesting a similar exchange between the Atlantic and Indian 
Oceans as recently as 12,000 years ago (Bowen et al., 1994). Bowen 
(2003) speculated that Indian-Atlantic Ocean exchanges took place via 
the temperate waters south of South Africa and became rare as the ocean 
shifted to cold temperate conditions in this region.
    To estimate loggerhead gene flow in and out of the Indian Ocean, 
J.S. Reece (Washington University, personal communication, 2008) 
examined 100 samples from Masirah Island, 249 from Atlantic rookeries 
(from Encalada et al., 1998), and 311 from Pacific rookeries (from 
Bowen et al., 1995 and Hatase et al., 2002a). Reece estimated that gene 
flow, expressed as number of effective migrants, or exchanges of 
breeding females between Indian Ocean rookeries and those from the 
Atlantic or Pacific occurred at the rate of less than 0.1 migrant per 
generation. Reece estimated gene flow based on coalescence of combined 
mtDNA and nuclear DNA data to be approximately 0.5 migrants per 
generation. These unpublished results, while somewhat theoretical, may 
indicate that there is restricted gene flow into and out of the Indian 
Ocean. The low level of gene flow most likely reflects the historical 
connectivity over geological timescales rather than any contemporary 
migration, and is consistent with Bowen et al.'s (1994) hypothesis that 
exchange occurred most recently over 12,000-3,000,000 years ago during 
the Pleistocene, and has been restricted over recent ecological 
timescales.
    The discrete status of three loggerhead populations in the Indian 
Ocean is primarily supported by observations of tag returns and 
satellite telemetry. The genetic information currently available based 
on mtDNA sequences does not allow for a comprehensive analysis of 
genetic population structure analysis for Indian Ocean rookeries, 
although Bowen et al. (1994) indicated the Oman and South African 
rookeries are genetically distinct, and, based on preliminary results, 
once sequencing studies are completed for these rookeries, it is likely 
that they will also be genetically distinct from the rookeries in 
Western Australia (P. Dutton, NMFS, unpublished data; N. FitzSimmons, 
University of Canberra, unpublished data; J. Reece, University of 
California at Santa Cruz, unpublished data). Based on multiple lines of 
evidence, discrete status is supported for the North Indian Ocean, 
Southeast Indo-Pacific Ocean, and Southwest Indian Ocean loggerhead 
populations. Although there is not a sufficiently clear picture of gene 
flow between these regions, significant vicariant barriers likely exist 
between these three Indian Ocean populations that would prevent 
migration of individuals on a time scale relative to management and 
conservation efforts. These biogeographical barriers are the 
oceanographic phenomena associated with Indian Ocean equatorial waters, 
and the large expanse between continents in the South Indian Ocean 
without suitable benthic foraging habitat.
    Given the information presented above, the BRT concluded, and we 
concur, that three discrete population segments exist in the Indian 
Ocean: (1) North Indian Ocean, (2) Southeast Indo-Pacific Ocean, and