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

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.

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

http://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

http://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

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

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. López-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; Monzón-Argüello

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.,

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). Monzón-Argüello

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) (Tomás

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.,

Camiñas

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 Gabès 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

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

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

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 Niño 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

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° N. lat.); distributions east and west are not restricted by landmasses south of approximately 38° 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° N. lat. (Baldwin

et al.,

2003). Other key nesting assemblages occur on the Al Halaniyat Islands, Oman (17° S. lat.) and on Oman's Persian Gulf mainland beaches south of Masirah Island to the Oman-Yemen border (17-20° 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

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 (3) Southwest Indian Ocean. These three population segments are markedly separated from each other and from population segments within the Pacific Ocean and Atlantic Ocean basins as a consequence of physical, ecological, behavioral, and oceanographic factors. Information supporting this conclusion is primarily based on 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 for Indian Ocean rookeries; however, the Oman and South African rookeries are genetically distinct (Bowen

et al.,

1994), and, based on preliminary results, once sequencing studies are completed for these rookeries, it is likely that they will also be determined 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). Furthermore, significant biogeographical barriers (i.e., oceanographic phenomena associated with Indian Ocean equatorial waters, and the large expanse between continents in the South Indian Ocean without suitable benthic foraging habitat) likely exist between these three Indian Ocean populations that would prevent migration of individuals on a time scale relative to management and conservation efforts. The separation of the Indian Ocean population segments from population segments within the Pacific 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). In the East Indian Ocean, although there is possible overlap with loggerheads that nest on Australia's Indian Ocean and Pacific Ocean coasts, extensive tagging at the principal nesting beaches on both coasts has revealed no exchange of females between these nesting beaches (Limpus, 2009).

Atlantic Ocean and Mediterranean Sea

Within the Atlantic Ocean, loss and re-colonization of nesting beaches over evolutionary time scales has been influenced by climate, natal homing, and rare dispersal events (Encalada

et al.,

1998; Bowen and Karl, 2007). At times, temperate beaches were too cool to incubate eggs and embryonic development could have succeeded only on tropical beaches. Thus, the contemporary distribution of nesting is the product of colonization events from the tropical refugia during the last 12,000 years. Apparently, turtles from the Northwest Atlantic colonized the Mediterranean and at least two matrilines were involved (Schroth

et al.,

1996); however, Mediterranean rookeries became isolated from the Atlantic populations in the last 10,000 years following the end of the Wisconsin glacial period (Encalada

et al.,

1998). A similar colonization event appears to have populated the Northeast Atlantic (Monzón-Argüello

et al.,

2010).

Nesting in the western South Atlantic occurs primarily along the mainland coast of Brazil from Sergipe south to Rio de Janeiro, with peak concentrations in northern Bahia, Espírito Santo, and northern Rio de Janeiro (Marcovaldi and Chaloupka, 2007). In the eastern South Atlantic, diffuse nesting may occur along the mainland coast of Africa (Fretey, 2001), with more than 200 loggerhead nests reported for Rio Longa beach in central Angola in 2005 (Brian, 2007). However, other researchers have been unable to confirm nesting by loggerheads in the last decade anywhere along the south Atlantic coast of Africa, including Angola (Fretey, 2001; Weir

et al.,

2007). There is the possibility that reports of nesting loggerheads from Angola and Namibia (Márquez M., 1990;

Brian, 2007) may have arisen from misidentified olive ridley turtles (Brongersma, 1982; Fretey, 2001). At the current time, it is not possible to confirm that regular, if any, nesting of loggerheads occurs along the Atlantic coast of Africa, south of the equator.

Genetic surveys of loggerheads have revealed that the Brazilian rookeries have a unique mtDNA haplotype (Encalada

et al.,

1998; Pearce, 2001). The Brazilian mtDNA haplotype, relative to North Atlantic haplotypes, indicates isolation of South Atlantic loggerheads from North Atlantic loggerheads on a scale of 250,000-500,000 years ago, and microsatellite DNA results show divergence on the same time scale (Bowen, 2003). Brazil's unique haplotype has been found only in low numbers in foraging populations of juvenile loggerheads of the North Atlantic (Bass

et al.,

2004). Other lines of evidence support a deep division between loggerheads from the South Atlantic and from the North Atlantic, including: (1) A nesting season in Brazil that peaks in the austral summer around December-January (Marcovaldi and Laurent, 1996), as opposed to the April-September nesting season in the southeastern United States in the northern hemisphere (Witherington

et al.,

2009); and (2) no observations of tagged loggerheads moving across the equator in the Atlantic, except a single case of a captive-reared animal that was released as a juvenile from Espírito Santo and was recaptured 3 years later in the Azores (Bolten

et al.,

1990). Post-nesting females from Espírito Santo, Brazil, moved either north or south along the coast, but remained between 10° S. lat. and 30° S. lat. (Marcovaldi

et al.,

2000; Lemke

et al.,

2006), while post-nesting females from Bahia, Brazil, all moved north (Marcovaldi

et al.,

2010).

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; Petersen

et al.,

2007; Weir

et al.,

2007) suggesting that, like their North Pacific, South Pacific, and Northwest Atlantic counterparts, loggerheads of the South Atlantic may undertake transoceanic developmental migrations (Bowen

et al.,

1995; Bolten

et al.,

1998; Peckham

et al.,

2007; Boyle

et al.,

2009). Marcovaldi

et al.

(2010) equipped 10 loggerheads nesting in Brazil with satellite transmitters to study their internesting and postnesting movements. At the conclusion of their nesting season, all 10 turtles migrated to the northern coast of Brazil to individual foraging areas on the continental shelf. Females were also tracked during a second postnesting migration back to their foraging areas, showing a strong fidelity to foraging grounds.

Within the Northwest Atlantic, the majority of nesting activity occurs from April through September, with a peak in June and July (Williams-Walls

et al.,

1983; Dodd, 1988; Weishampel

et al.,

2006). Nesting occurs within the Northwest Atlantic along the coasts of North America, Central America, northern South America, the Antilles, and The Bahamas, but is concentrated in the southeastern United States and on the Yucatan Peninsula in Mexico (Sternberg, 1981; Ehrhart, 1989; Ehrhart

et al.,

2003; NMFS and USFWS, 2008). Five recovery units (management subunits of a listed species that are geographically or otherwise identifiable and essential to the recovery of the species) have been identified based on genetic differences and a combination of geographic distribution of nesting densities and geographic separation (NMFS and USFWS, 2008). These recovery units are: Northern Recovery Unit (Florida/Georgia border through southern Virginia), Peninsular Florida Recovery Unit (Florida/Georgia border through Pinellas County, Florida), Dry Tortugas Recovery Unit (islands located west of Key West, Florida), Northern Gulf of Mexico Recovery Unit (Franklin County, Florida, through Texas), and Greater Caribbean Recovery Unit (Mexico through French Guiana, The Bahamas, Lesser Antilles, and Greater Antilles) (NMFS and USFWS, 2008).

Loggerheads in the Northwest Atlantic have a complex population genetic structure. Based on mtDNA evidence, oceanic juveniles show no structure, neritic juveniles show moderate structure, and nesting colonies show strong structure (Bowen

et al.,

2005). In contrast, a study using microsatellite (nuclear DNA) markers showed no significant population structure among nesting populations (Bowen

et al.,

2005), indicating that while females exhibit strong philopatry, males may provide an avenue of gene flow between nesting colonies in this region. Nevertheless, Bowen

et al.

(2005) argued that male-mediated gene flow within the Northwest Atlantic does not detract from the classification of breeding areas as independent populations (

e.g.,

management/recovery units) because the production of progeny depends on female nesting success. All Northwest Atlantic recovery units are reproductively isolated from populations within the Northeast Atlantic, South Atlantic, and Mediterranean Sea.

As oceanic juveniles, loggerheads from the Northwest Atlantic use the North Atlantic Gyre and often are associated with

Sargassum

communities (Carr, 1987). They also are found in the Mediterranean Sea. 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; Bowen

et al.,

2005; LaCasella

et al.,

2005; Carreras

et al.,

2006; Monzón-Argüello

et al.,

2006; Revelles

et al.,

2007). In the western Mediterranean, they tend to be associated with the waters off the northern African coast and the northeastern Balearic Archipelago, areas generally not inhabited by turtles of Mediterranean origin (Carreras

et al.,

2006; Revelles

et al.,

2007; Eckert

et al.,

2008). As larger neritic juveniles, they show more structure and tend to inhabit areas closer to their natal origins (Bowen

et al.,

2004), but some do move to and from oceanic foraging grounds throughout this life stage (McClellan and Read, 2007; Mansfield

et al.,

2009; McClellan

et al.,

2010), and some continue to use the Mediterranean Sea (Casale

et al.,

2008a; Eckert

et al.,

2008).

Adult populations are highly structured with no overlap in distribution among adult loggerheads from the Northwest Atlantic, Northeast Atlantic, South Atlantic, and Mediterranean. Carapace epibionts suggest the adult females of different subpopulations use different foraging habitats (Caine, 1986). In the Northwest Atlantic, based on satellite telemetry studies and flipper tag returns, non-nesting adult females from the Northern Recovery Unit reside primarily off the east coast of the United States; movement into the Bahamas or the Gulf of Mexico is rare (Bell and Richardson, 1978; Williams and Frick, 2001; Mansfield, 2006; Turtle Expert Working Group (TEWG), 2009). Adult females of the Peninsular Florida Recovery Unit are distributed throughout eastern Florida, The Bahamas, Greater Antilles, the Yucatan Peninsula of Mexico, and the Gulf of Mexico, as well as along the Atlantic seaboard of the United States (Meylan, 1982; Meylan

et al.,

1983; Foley

et al.,

2008; TEWG, 2009). Adult females from the Northern Gulf of Mexico Recovery Unit remained in the Gulf of Mexico, including off the Yucatan Peninsula of Mexico, based on satellite telemetry and flipper tag returns (Foley

et al.,

2008; TEWG, 2009;

M. Lamont, Florida Cooperative Fish and Wildlife Research Unit, personal communication, 2009; M. Nicholas, National Park Service, personal communication, 2009).

Nesting in the Northeast Atlantic is concentrated in the Cape Verde Archipelago, with some nesting occurring on most of the islands, and the highest concentration on the beaches of Boa Vista Island (López-Jurado

et al.,

2000; Varo Cruz

et al.,

2007; Loureiro, 2008; Monzón-Argüello

et al.,

2010). On mainland Africa, there is minor nesting on the coasts of Mauritania to Senegal (Brongersma, 1982; Arvy

et al.,

2000; Fretey, 2001). Earlier reports of loggerhead nesting in Morocco (Pasteur and Bons, 1960) have not been confirmed in recent years (Tiwari

et al.,

2001). Nesting has not been reported from Macaronesia (Azores, Madeira Archipelago, The Selvagens Islands, and the Canary Islands), other than in the Cape Verde Archipelago (Brongersma, 1982). In Cape Verde, nesting begins in mid-June and extends into October (Cejudo

et al.,

2000), which is somewhat later than when nesting occurs in the Northwest Atlantic.

Based on an analysis of mtDNA of nesting females from Boa Vista Island, the Cape Verde nesting assemblage is genetically distinct from other studied rookeries (Monzón-Argüello

et al.,

2009, 2010). The results also indicate that despite the close proximity of the Mediterranean, the Boa Vista rookery is most closely related to the rookeries of the Northwest Atlantic.

The distribution of juvenile loggerheads from the Northeast Atlantic is largely unknown but they have been found on the oceanic foraging grounds of the North Atlantic (A. Bolten, University of Florida, personal communication, 2008, based on Bolten

et al.,

1998 and LaCasella

et al.,

2005; Monzón-Argüello

et al.,

2009; M. Tiwari, NMFS, and A. Bolten, University of Florida, unpublished data) and in the western and central Mediterranean (A. Bolten, University of Florida, personal communication, 2008, based on Carreras

et al.,

2006), along with small juvenile loggerheads from the Northwest Atlantic. The size of nesting females in the Northeast Atlantic is comparable to those in the Mediterranean (average 72-80 cm straight carapace length (SCL); Margaritoulis

et al.,

2003) and smaller than those in the Northwest Atlantic or the South Atlantic; 91 percent of the nesting turtles are less than 86.5 cm curved carapace length (CCL) (Hawkes

et al.,

2006) and nesting females average 77.1 cm SCL (Cejudo

et al.,

2000). Satellite-tagged, post-nesting females from Cape Verde foraged in coastal waters along northwest Africa or foraged oceanically, mostly between Cape Verde and the African shelf from Mauritania to Guinea Bissau (Hawkes

et al.,

2006).

In the Mediterranean, nesting occurs throughout the central and eastern basins on the shores of Italy, Greece, Cyprus, Turkey, Syria, Lebanon, Israel, the Sinai, Egypt, Libya, and Tunisia (Sternberg, 1981; Margaritoulis

et al.,

2003; SWOT, 2007; Casale and Margaritoulis, 2010). Sporadic nesting also has been reported in the western Mediterranean on Corsica (Delaugerre and Cesarini, 2004), southwestern Italy (Bentivegna

et al.,

2005), and on the Spanish Mediterranean coast (Tomás

et al.,

2003, 2008). Nesting in the Mediterranean is concentrated between June and early August (Margaritoulis

et al.,

2003; Casale and Margaritoulis, 2010).

Within the Mediterranean, a recent study of mtDNA and nuclear DNA in nesting assemblages from Greece to Israel indicated genetic structuring, philopatry by both females and males, and limited gene flow between assemblages (Carreras

et al.,

2007). Genetic differentiation based on mtDNA indicated that there are at least four independent nesting assemblages within the Mediterranean and usually they are characterized by a single haplotype: (1) Mainland Greece and the adjoining Ionian Islands, (2) eastern Turkey, (3) Israel, and (4) Cyprus. There is no evidence of adult female exchange among these four assemblages (Carreras

et al.,

2006). In studies of the foraging grounds in the western and central Mediterranean, seven of the 17 distinct haplotypes detected had not yet been described, indicating that nesting beach data to describe the natal origins of juveniles exploiting the western Mediterranean Sea are incomplete (Carreras

et al.,

2006; Casale

et al.,

2008a). Gene flow among the Mediterranean rookeries estimated from nuclear DNA was significantly higher than that calculated from mtDNA, consistent with the scenario of female philopatry maintaining isolation between rookeries, offset by male-mediated gene flow. Nevertheless, the nuclear data show there was a higher degree of substructuring among Mediterranean rookeries compared to those in the Northwest Atlantic (Bowen

et al.,

2005; Carreras

et al.,

2007).

Small oceanic juveniles from the Mediterranean Sea use the eastern basin (defined as inclusive of the central Mediterranean, Ionian, Adriatic, and Aegean Seas) and the western basin (defined as inclusive of the Tyrrhenian Sea) along the European coast (Laurent

et al.,

1998; Margaritoulis

et al.,

2003; Carreras

et al.,

2006; Revelles

et al.,

2007). Carreras

et al.

(2006) believe this genetic structuring is explained by the pattern of sea surface currents and water masses, with a limited exchange of juvenile loggerheads between water masses. Larger juveniles also use the eastern Atlantic and the eastern Mediterranean, especially the Tunisia-Libya shelf and the Adriatic Sea (Laurent

et al.,

1993; Margaritoulis

et al.,

2003; Monzón-Argüello

et al.,

2006; Revelles

et al.,

2007; Eckert

et al.,

2008). Adults appear to forage closer to the nesting beaches in the eastern basin; most tag recoveries from females nesting in Greece have occurred in the Adriatic Sea and off Tunisia (Margaritoulis

et al.,

2003; Lazar

et al.,

2004).

Loggerheads nesting in the Mediterranean were significantly smaller than loggerheads nesting in the Northwest Atlantic and the South Atlantic. Within the Mediterranean, carapace lengths ranged from 58 to 95 cm SCL (Margaritoulis

et al.,

2003). Greece's loggerheads averaged 77-80 cm SCL (Tiwari and Bjorndal, 2000; Margaritoulis

et al.,

2003), whereas Turkey's loggerheads averaged 72-73 cm SCL (Margaritoulis

et al.,

2003). The Greece turtles also produced larger clutches (relative to body size) than those produced by Florida or Brazil nesters (Tiwari and Bjorndal, 2000).

Given the information presented above, the BRT concluded, and we concur, that four discrete population segments exist in the Atlantic Ocean/Mediterranean: (1) Northwest Atlantic Ocean, (2) Northeast Atlantic Ocean, (3) South Atlantic Ocean, and (4) Mediterranean Sea. These four population segments are markedly separated from each other and from population segments within the Pacific Ocean and Indian 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. Genetic studies have shown that adult populations are highly structured with no overlap in distribution among adult loggerheads in these four population segments (Bowen

et al.,

1994; Encalada

et al.,

1998; Pearce, 2001; Carerras

et al.,

2007; Monzón-Argüello

et al.,

2009, 2010). Although loggerheads from the Northwest Atlantic, Northeast Atlantic, and Mediterranean Sea population segments may comingle on oceanic foraging grounds as juveniles, adults are apparently isolated from each other; they also differ demographically. Data from satellite telemetry studies and

flipper tag returns have shown that nesting females from the Northwest Atlantic return to the same nesting areas; they reveal no evidence of movement of adults south of the equator or east of 40° W. longitude. Similarly, there is no evidence of movement of Northeast Atlantic adults south of the equator, west of 40° W. long., or east of the Strait of Gibraltar, a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea. Also, there is no evidence of movement of adult Mediterranean Sea loggerheads west of the Strait of Gibraltar. With regard to South Atlantic loggerheads, there have been no observations of tagged loggerheads moving across the equator in the Atlantic, except a single case of a captive-reared animal that was released as a juvenile from Espírito Santo and was recaptured 3 years later in the Azores (Bolten

et al.,

1990). The separation of the Atlantic Ocean/Mediterranean Sea population segments from population segments within the Indian Ocean and Pacific 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).

Significance Determination

As stated in the preceding section, the BRT identified nine discrete population segments. As described below by ocean basin, the BRT found that each of the nine discrete population segments is biologically and ecologically significant. They each represent a large portion of the species' range, sometimes encompassing an entire hemispheric ocean basin. The range of each discrete population segment occurs within a unique ecosystem that has significantly influenced each population in physiology, morphology, and genetics. The loss of any individual discrete population segment would result in a significant gap in the loggerhead's range. Each discrete population segment is genetically distinct, often identified by unique mtDNA haplotypes, and the BRT suggested that this geographic partitioning of genetic variation could also indicate adaptive differences; the loss of any one discrete population segment would represent a significant loss of genetic diversity. Therefore, the BRT concluded, and we concur, that these nine population segments are both discrete from other conspecific population segments and significant to the species to which they belong,

Caretta caretta.

The geographic delineations given below for each discrete population segment were determined primarily based on nesting beach locations, genetic evidence, oceanographic features, thermal tolerance, fishery bycatch data, and information on loggerhead distribution and migrations from satellite telemetry and flipper tagging studies (see Map of Loggerhead Sea Turtle DPS Boundaries). With rare exception, adults from discrete population segments remain within the delineated boundaries. In some cases, juvenile turtles from two or more discrete population segments may mix on foraging areas and, therefore, their distribution and migrations may extend beyond the geographic boundaries delineated below for each discrete population segment (

e.g.,

juvenile turtles from the Northwest Atlantic Ocean, Northeast Atlantic Ocean, and Mediterranean Sea discrete population segments share foraging habitat in the western Mediterranean Sea).

ER22SE11.007

Pacific Ocean

The BRT considered 60° N. lat. and the equator as the north and south boundaries, respectively, of the North Pacific Ocean population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the North Pacific Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs

markedly from other population segments of the species in its genetic characteristics. The North Pacific Ocean population segment encompasses an entire hemispheric ocean basin and its loss would result in a significant gap in the range of the taxon. There is no evidence or reason to believe that female loggerheads from South Pacific nesting beaches would repopulate the North Pacific nesting beaches should those nesting assemblages be lost (Bowen

et al.,

1994; Bowen, 2003). Tagging studies show that the vast majority of nesting females return to the same nesting area. As summarized by Hatase

et al.

(2002a), of 2,219 tagged nesting females from Japan, only five females were subsequently documented nesting away (between 74 and 630 km) from where they were originally encountered. In addition, flipper tag and satellite telemetry research, as described in detail in the Discreteness Determination section above, has shown no evidence of north-south movement of loggerheads across the equator. This discrete population segment is genetically unique (see Discreteness Determination section above) and the BRT indicated that these unique haplotypes could represent adaptive differences; thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the North Pacific Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered the equator and 60° S. lat. as the north and south boundaries, respectively, and 67° W. long. and 141° E. long. as the east and west boundaries, respectively, of the South Pacific Ocean population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the South Pacific Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The South Pacific Ocean population segment encompasses an entire hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. The South Pacific Ocean population is the only population of loggerheads found south of the equator in the Pacific Ocean and there is no evidence or reason to believe that female loggerheads from North Pacific nesting beaches would repopulate the South Pacific nesting beaches should those nesting assemblages be lost (Bowen

et al.,

1994; Bowen, 2003). In addition, flipper tag and satellite telemetry research, as described in detail in the Discreteness Determination section above, has shown no evidence of north-south movement of loggerheads across the equator. The BRT also stated that it does not expect that recolonization from Indian Ocean loggerheads would occur in eastern Australia within ecological time frames. Despite evidence of foraging in the Gulf of Carpentaria by adult loggerheads from the nesting populations in eastern Australia (South Pacific Ocean population segment) and western Australia (Southeast Indo-Pacific Ocean population segment), the nesting females from these two regions are considered to be genetically distinct from one another (Limpus, 2009). In addition to a substantial disparity in mtDNA haplotype frequencies between these two populations, FitzSimmons (University of Canberra, unpublished data) found significant differences in nuclear DNA microsatellite loci between females nesting in these two regions, indicating separation between the South Pacific Ocean and the Southeast Indo-Pacific Ocean population segments. Long-term studies show a high degree of site fidelity by adult females in the South Pacific, with most females returning to the same beach within a nesting season and in successive nesting seasons (Limpus, 1985, 2009; Limpus

et al.,

1994). This has been documented as characteristic of loggerheads from various rookeries throughout the world (Schroeder

et al.,

2003). This discrete population segment is genetically unique and the BRT indicated that these unique haplotypes could represent adaptive differences. Thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the South Pacific Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

Indian Ocean

The BRT considered 30° N. lat. and the equator as the north and south boundaries, respectively, of the North Indian Ocean population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the North Indian Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The North Indian Ocean population segment encompasses an entire hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic information currently available for Indian Ocean populations indicates that the Oman rookery in the North Indian Ocean and the South African rookery in the Southwest Indian Ocean are genetically distinct (Bowen

et al.,

1994), and, based on preliminary results, once sequencing studies are completed for these rookeries, it is likely that they will also be determined to be genetically distinct from the Western Australia rookeries in the Southeast Indo-Pacific Ocean (P. Dutton, NMFS, unpublished data; N. FitzSimmons, University of Canberra, unpublished data; J. Reece, University of California at Santa Cruz, unpublished data). In addition, oceanographic phenomena associated with Indian Ocean equatorial waters exist between the North Indian Ocean population segment and the two population segments in the South Indian Ocean, which likely prevent migration of individuals across the equator on a time scale relative to management and conservation efforts (Conant

et al.,

2009). Therefore, there is no evidence or reason to believe that female loggerheads from the Southwest Indian Ocean or Southeast Indo-Pacific Ocean would repopulate the North Indian Ocean nesting beaches should those populations be lost (Bowen

et al.,

1994; Bowen, 2003). Based on this information, the BRT concluded, and we concur, that the North Indian Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered the equator and 60° S. lat. as the north and south boundaries, respectively, and 20° E. long. at Cape Agulhas on the southern tip of Africa and 80° E. long. as the east and west boundaries, respectively, of the Southwest Indian Ocean population segment based on oceanographic features, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite

telemetry and flipper tagging studies. The BRT determined that the Southwest Indian Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The Southwest Indian Ocean population segment encompasses half of a hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic information currently available for Indian Ocean populations indicates that the Oman rookery in the North Indian Ocean and the South African rookery in the Southwest Indian Ocean are genetically distinct (Bowen

et al.,

1994), and, based on preliminary results, once sequencing studies are completed for these rookeries, it is likely that they will also be determined to be genetically distinct from the Western Australia rookeries in the Southeast Indo-Pacific Ocean (P. Dutton, NMFS, unpublished data; N. FitzSimmons, University of Canberra, unpublished data; J. Reece, University of California at Santa Cruz, unpublished data). In addition, biogeographical barriers (

i.e.,

oceanographic phenomena associated with Indian Ocean equatorial waters, and the large expanse between continents in the South Indian Ocean without suitable benthic foraging habitat) likely exist between the three Indian Ocean populations that would prevent migration of individuals between populations on a time scale relative to management and conservation efforts (Conant

et al.,

2009). Therefore, there is no evidence or reason to believe that female loggerheads from the North Indian Ocean or Southeast Indo-Pacific Ocean would repopulate the Southwest Indian Ocean nesting beaches should those populations be lost (Bowen

et al.,

1994; Bowen, 2003). There is also no evidence of movement of adult Southwest Indian Ocean loggerheads west of 20° E. long. at Cape Agulhas, the southernmost point on the African continent, or east of 80° E. long. within the Indian Ocean. Based on this information, the BRT concluded, and we concur, that the Southwest Indian Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered the equator and 60° S. lat. as the north and south boundaries, respectively, and 141° E. long. and 80° E. long. as the east and west boundaries, respectively, of the Southeast Indo-Pacific Ocean population segment based on oceanographic features, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the Southeast Indo-Pacific Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The Southeast Indo-Pacific Ocean population segment encompasses half of a hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic information currently available for Indian Ocean populations indicates that the Oman rookery in the North Indian Ocean and the South African rookery in the Southwest Indian Ocean are genetically distinct (Bowen

et al.,

1994), and, based on preliminary results, once sequencing studies are completed for these rookeries, it is likely that they will also be determined to be genetically distinct from the Western Australia rookeries in the Southeast Indo-Pacific Ocean (P. Dutton, NMFS, unpublished data; N. FitzSimmons, University of Canberra, unpublished data; J. Reece, University of California at Santa Cruz, unpublished data). In addition, biogeographical barriers (

i.e.,

oceanographic phenomena associated with Indian Ocean equatorial waters, and the large expanse between continents in the South Indian Ocean without suitable benthic foraging habitat) likely exist between the three Indian Ocean populations that would likely prevent migration of individuals between populations on a time scale relative to management and conservation efforts (Conant

et al.,

2009). Therefore, there is no evidence or reason to believe that female loggerheads from the North Indian Ocean or Southwest Indian Ocean would repopulate the Southeast Indo-Pacific Ocean nesting beaches should those populations be lost (Bowen

et al.,

1994; Bowen, 2003). There is also no evidence of movement of adult Southeast Indo-Pacific Ocean loggerheads west of 80° E. long. within the Indian Ocean. Despite evidence of foraging in the Gulf of Carpentaria by adult loggerheads from the nesting populations in eastern Australia (South Pacific Ocean population segment) and western Australia (Southeast Indo-Pacific Ocean population segment), the nesting females from these two regions are considered to be genetically distinct from one another (Limpus, 2009). In addition to a substantial disparity in mtDNA haplotype frequencies between these two regions, FitzSimmons (University of Canberra, unpublished data) found significant differences in nuclear DNA microsatellite loci from females nesting in these two regions, indicating separation between the South Pacific Ocean population segment and the Southeast Indo-Pacific Ocean population segment. Based on this information, the BRT concluded, and we concur, that the Southeast Indo-Pacific Ocean population segment is significant to the taxon to which it belongs, and, therefore, it satisfies the significance element of the DPS policy.

Atlantic Ocean and Mediterranean Sea

The BRT considered 60° N. lat. and the equator as the north and south boundaries, respectively, and 40° W. long. as the eastern boundary of the Northwest Atlantic Ocean population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the Northwest Atlantic Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The Northwest Atlantic Ocean population segment encompasses half of a hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic studies have shown that adult populations are highly structured with no overlap in distribution among adult loggerheads from the Northwest Atlantic, Northeast Atlantic, South Atlantic, and Mediterranean Sea (Bowen

et al.,

1994; Encalada

et al.,

1998; Pearce, 2001; Carerras

et al.,

2007; Monzón-Argüello

et al.,

2009, 2010). There is no evidence or reason to believe that female loggerheads from the Northeast Atlantic, Mediterranean Sea, or South Atlantic nesting beaches would repopulate the Northwest Atlantic nesting beaches should these populations be lost (Bowen

et al.,

1994; Bowen, 2003). Data from satellite telemetry studies and flipper tag returns, as described in detail in the Discreteness Determination section above, have shown that the vast majority of nesting females from the Northwest Atlantic return to the same

nesting area; they reveal no evidence of movement of adults south of the equator or east of 40° W. longitude. This discrete population segment is genetically distinct (see Discreteness Determination section above) possibly indicating adaptive differences as suggested by the BRT; thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the Northwest Atlantic Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered 60° N. lat. and the equator as the north and south boundaries, respectively, and 40° W. long. as the west boundary of the Northeast Atlantic Ocean population segment. The BRT considered the boundary between the Northeast Atlantic Ocean and Mediterranean Sea population segments as 5° 36′ W. long. (Strait of Gibraltar). These boundaries are based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the Northeast Atlantic Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The Northeast Atlantic Ocean population segment encompasses half of a hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic studies have shown that adult populations are highly structured with no overlap in distribution among adult loggerheads from the Northwest Atlantic, Northeast Atlantic, South Atlantic, and Mediterranean Sea (Bowen

et al.,

1994; Encalada

et al.,

1998; Pearce, 2001; Carerras

et al.,

2007; Monzón-Argüello

et al.,

2009, 2010). There is no evidence or reason to believe that female loggerheads from the Northwest Atlantic, Mediterranean Sea, or South Atlantic nesting beaches would repopulate the Northeast Atlantic nesting beaches should these populations be lost (Bowen

et al.,

1994; Bowen, 2003). There is also no evidence of movement of Northeast Atlantic adults west of 40° W. long. or, in the vicinity of the Strait of Gibraltar (the boundary between the Northeast Atlantic Ocean and Mediterranean Sea population segments), no evidence of movement east of 5° 36′ W. longitude. This discrete population segment is genetically unique (see Discreteness Determination section above) and the BRT indicated that these unique haplotypes could represent adaptive differences; thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the Northeast Atlantic Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered the Mediterranean Sea west to 5°36′ W. long. (Strait of Gibraltar) as the boundary of the Mediterranean Sea population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the Mediterranean Sea discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The Mediterranean Sea population segment encompasses the entire Mediterranean Sea basin, and its loss would result in a significant gap in the range of the taxon. Genetic studies have shown that adult populations are highly structured with no overlap in distribution among adult loggerheads from the Northwest Atlantic, Northeast Atlantic, South Atlantic, and Mediterranean Sea (Bowen

et al.,

1994; Encalada

et al.,

1998; Pearce, 2001; Carerras

et al.,

2007; Monzón-Argüello

et al.,

2009, 2010). There is no evidence or reason to believe that female loggerheads from the Northwest Atlantic, Northeast Atlantic, or South Atlantic nesting beaches would repopulate the Mediterranean Sea nesting beaches should these populations be lost (Bowen

et al.,

1994; Bowen, 2003). As previously described, adults from the Mediterranean Sea population segment appear to forage closer to the nesting beaches in the eastern basin, and most flipper tag recoveries from females nesting in Greece have occurred in the Adriatic Sea and off Tunisia (Margaritoulis

et al.,

2003; Lazar

et al.,

2004). There is no evidence of movement of adult Mediterranean Sea loggerheads west of the Strait of Gibraltar (5°36′ W. long.). This discrete population segment is genetically unique (see Discreteness Determination section above) and the BRT indicated that these unique haplotypes could represent adaptive differences; thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the Mediterranean Sea population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

The BRT considered the equator and 60° S. lat. as the north and south boundaries, respectively, and 20° E. long. at Cape Agulhas on the southern tip of Africa and 67° W. long. as the east and west boundaries, respectively, of the South Atlantic Ocean population segment based on oceanographic features, loggerhead sightings, thermal tolerance, fishery bycatch data, and information on loggerhead distribution from satellite telemetry and flipper tagging studies. The BRT determined that the South Atlantic Ocean discrete population segment is biologically and ecologically significant because the loss of this population segment would result in a significant gap in the range of the taxon, and the population segment differs markedly from other population segments of the species in its genetic characteristics. The South Atlantic Ocean population segment encompasses an entire hemispheric ocean basin, and its loss would result in a significant gap in the range of the taxon. Genetic studies have shown that adult populations are highly structured with no overlap in distribution among adult loggerheads from the Northwest Atlantic, Northeast Atlantic, South Atlantic, and Mediterranean Sea (Bowen

et al.,

1994; Encalada

et al.,

1998; Pearce, 2001; Carerras

et al.,

2007; Monzón-Argüello

et al.,

2009, 2010). There is no evidence or reason to believe that female loggerheads from the Northwest Atlantic, Northeast Atlantic, or Mediterranean Sea nesting beaches would repopulate the South Atlantic nesting beaches should these populations be lost (Bowen

et al.,

1994; Bowen, 2003). This discrete population segment is genetically unique (see Discreteness Determination section above) and the BRT indicated that these unique haplotypes could represent adaptive differences; thus, the loss of this discrete population segment would represent a significant loss of genetic diversity. Based on this information, the BRT concluded, and we concur, that the

South Atlantic Ocean population segment is significant to the taxon to which it belongs, and, therefore, that it satisfies the significance element of the DPS policy.

In summary, based on the information provided in the Discreteness Determination and Significance Determination sections above, the BRT identified nine loggerhead DPSs distributed globally: (1) North Pacific Ocean DPS, (2) South Pacific Ocean DPS, (3) North Indian Ocean DPS, (4) Southeast Indo-Pacific Ocean DPS, (5) Southwest Indian Ocean DPS, (6) Northwest Atlantic Ocean DPS, (7) Northeast Atlantic Ocean DPS, (8) Mediterranean Sea DPS, and (9) South Atlantic Ocean DPS. We concur with the findings and application of the DPS policy described by the BRT and herein delineate the nine DPSs identified by the BRT as DPSs (

i.e.,

they are discrete and significant).

Significant Portion of the Range

We have determined that the range of each DPS contributes meaningfully to the conservation of the DPS and that populations that may contribute more or less to the conservation of each DPS throughout a portion of its range cannot be identified due to the highly migratory nature of the listed entity.

The loggerhead sea turtle is highly migratory and crosses multiple domestic and international geopolitical boundaries. Depending on the life stage, they may occur in oceanic waters or along the continental shelf of landmasses, or transit back and forth between oceanic and neritic habitats. Protection and management of both the terrestrial and marine environments is essential to recovering the listed entity. Management measures implemented by any State, foreign nation, or political subdivision likely would only affect individual sea turtles during certain stages and seasons of the life cycle. Management measures implemented by any State, foreign nation, or political subdivision may also affect individuals from multiple DPSs because juvenile turtles from disparate DPSs can overlap on foraging grounds or migratory corridors (

e.g.,

Northwest Atlantic, Northeast Atlantic, and Mediterranean Sea DPSs). The term “significant portion of its range” is not defined by the statute. For the purposes of this rule, a portion of the species' (species or distinct population segment) range is “significant” if its contribution to the viability of the species is so important that without that portion the species would be in danger of extinction. The BRT was unable to identify any particular portion of the range of any of the DPSs that was more significant to the DPS than another portion of the same range because of the species' migratory nature, the varying threats that affect different life stages, and the varying benefits accruing from conservation efforts throughout the geographic range of each DPS. The next section describes our evaluation of the status of each DPS throughout its range.

Status and Trends of the Nine Loggerhead DPSs

Complete population abundance estimates do not exist for the nine DPSs. Within the global range of the species, and within each DPS, the primary data available are collected on nesting beaches, either as counts of nests or counts of nesting females, or a combination of both (either direct or extrapolated). Information on abundance and trends away from the nesting beaches is limited or non-existent, primarily because these data are, relative to nesting beach studies, logistically difficult and expensive to obtain. Therefore, the primary information source for directly evaluating status and trends of the nine DPSs is nesting beach data.

North Pacific Ocean DPS

In the North Pacific, loggerhead nesting is essentially restricted to Japan where monitoring of loggerhead nesting began in the 1950s on some beaches, and expanded to include most known nesting beaches since approximately 1990. Kamezaki

et al.

(2003) reviewed census data collected from most of the Japanese nesting beaches. Although most surveys were initiated in the 1980s and 1990s, some data collection efforts were initiated in the 1950s. Along the Japanese coast, nine major nesting beaches (greater than 100 nests per season) and six “submajor” beaches (10-100 nests per season) were identified. Census data from 12 of these 15 beaches provide composite information on longer-term trends in the Japanese nesting assemblage. Using information collected on these beaches, Kamezaki

et al.

(2003) concluded a substantial decline (50-90 percent) in the size of the annual loggerhead nesting population in Japan since the 1950s. Snover (2008) combined nesting data from the Sea Turtle Association of Japan and data from Kamezaki

et al.

(2002) to analyze an 18-year time series of nesting data from 1990-2007. Nesting declined from an initial peak of approximately 6,638 nests in 1990-1991, followed by a steep decline to a low of 2,064 nests in 1997. During the past decade, nesting increased gradually to 5,167 nests in 2005, declined and then rose again to a high of just under 11,000 nests in 2008. Estimated nest numbers for 2009 were on the order of 7,000-8,000 nests. While nesting numbers have gradually increased in recent years and the number for 2009 was similar to the start of the time series in 1990, historical evidence from Kamouda Beach (census data dates back to the 1950s) indicates that there has been a substantial decline over the last half of the 20th century (Kamezaki

et al.,

2003) and that current nesting represents a fraction of historical nesting levels.

South Pacific Ocean DPS

In the South Pacific, loggerhead nesting is almost entirely restricted to eastern Australia (primarily Queensland) and New Caledonia, and the population has been well studied. The size of the annual breeding population (females only) has been monitored at numerous rookeries in Australia since 1968 (Limpus and Limpus, 2003a), and these data constitute the primary measure of the current status of the DPS. The total nesting population for Queensland was approximately 3,500 females in the 1976-1977 nesting season (Limpus, 1985; Limpus and Reimer, 1994). Little more than two decades later, Limpus and Limpus (2003a) estimated this nesting population at less than 500 females in the 1999-2000 nesting season. There has been a marked decline in the number of females breeding annually since the mid-1970s, with an estimated 50 to 80 percent decline in the number of breeding females at various Australian rookeries up to 1990 (Limpus and Reimer, 1994) and a decline of approximately 86 percent from 1976-1999 (Limpus and Limpus, 2003a). However, since 2000, this long-term decline in the number of nesting females has reversed with increasing numbers of nesting females observed from 2000-2009 (Limpus, in press). More recent data for Mon Repos have shown increased nesting; 2009 nesting numbers were similar to nesting numbers recorded in the 1990s (M. Hamann, James Cook University, personal communication, 2010). However, comparable nesting surveys have not been conducted in New Caledonia. Information from a pilot study conducted in 2005 combined with oral history information collected suggest that there has been a decline in loggerhead nesting over recent decades (Limpus

et al.,

2006). Based on data from the pilot study, only 60 to 70 loggerheads nested on the four surveyed New Caledonia beaches during the

2004-2005 nesting season (Limpus

et al.,

2006).

Studies of eastern Australia loggerheads at their foraging areas provide some information on the status of non-breeding loggerheads of the South Pacific Ocean DPS. Chaloupka and Limpus (2001) determined that the resident loggerhead population on coral reefs of the southern Great Barrier Reef declined at 3 percent per year from 1985 to the late 1990s. The observed decline occurred in spite of constant high annual survivorship measured at this foraging habitat and was hypothesized to result from recruitment failure from fox predation of eggs at mainland rookeries during the 1960s and pelagic juvenile mortality from incidental capture in longline fisheries since the 1970s (Chaloupka and Limpus, 2001). Concurrently, a decline in new recruits was measured in these foraging areas (Limpus and Limpus, 2003a).

North Indian Ocean DPS

The North Indian Ocean hosts the largest nesting assemblage of loggerheads in the eastern hemisphere; the vast majority of these loggerheads nest in Oman (Baldwin

et al.,

2003). Nesting occurs in greatest density on Masirah Island; the number of emergences ranges from 27-102 per km nightly (Ross, 1998). Nesting densities have complicated the implementation of standardized nesting beach surveys, and more precise nesting data have only been collected since 2008. Extrapolations resulting from partial surveys and tagging in 1977-1978 provided broad estimates of 19,000 to 60,000 females nesting annually at Masirah Island in 1977 and 28,000 to 35,000 in 1978. A more recent partial survey in 1991 provided an estimate of 23,000 nesting females at Masirah Island (Ross, 1979, 1998; Ross and Barwani, 1982; Baldwin, 1992). A reinterpretation of the 1977-1978 estimates, assuming 50 percent nesting success (as compared to 100 percent in the original estimates), resulted in an estimate of 20,000 to 40,000 females nesting annually (Baldwin

et al.,

2003). Reliable trends in nesting cannot be determined due to the lack of standardized surveys at Masirah Island prior to 2008. From 2008 through 2010, approximately 50,000, 67,600, and 62,400 nests, respectively, were estimated annually based on standardized daily surveys of the highest density nesting beaches and weekly surveys on all remaining island nesting beaches. Using an estimated clutch frequency of five nests per nesting female this would convert to 10,000, 13,520, and 12,480 nesting females annually (Conant

et al.,

2009). Even using the low end of the 1977-1978 estimates of 20,000 nesting females at Masirah, this suggests a significant decline in the size of the nesting population and is consistent with observations by long-term resident rangers that the population has declined substantially in the last three decades (E. Possardt, USFWS, personal communication, 2008).

In addition to the nesting beaches on Masirah Island, over 3,000 nests per year have been recorded in Oman on the Al-Halaniyat Islands and, along the Oman mainland of the Arabian Sea, approximately 2,000 nests are deposited annually (Salm, 1991; Salm

et al.,

1993). In Yemen, on Socotra Island, 50-100 loggerheads were estimated to have nested in 1999 (Pilcher and Saad, 2000). A time series of nesting data based on standardized surveys is not available to determine trends for these nesting sites.

Loggerhead nesting is rare elsewhere in the northern Indian Ocean and in some cases is complicated by inaccurate species identification (Shanker, 2004; Tripathy, 2005). A small number of nesting females use the beaches of Sri Lanka every year; however, there are no records to suggest that Sri Lanka has ever been a major nesting area for loggerheads (Kapurusinghe, 2006). Loggerheads have been reported nesting in low numbers in Myanmar; however, these data may not be reliable because of misidentification of species (Thorbjarnarson

et al.,

2000).

Southeast Indo-Pacific Ocean DPS

In the eastern Indian Ocean, loggerhead nesting is restricted to Western Australia (Dodd, 1988), and this nesting population is the largest in Australia (Wirsing

et al.,

unpublished data, cited in Natural Heritage Trust, 2005; Limpus, 2009).

Dirk Hartog Island hosts about 70-75 percent of nesting individuals in the eastern Indian Ocean (Baldwin

et al.,

2003). Surveys were conducted on the island for the duration of six nesting seasons between 1993/1994 and 1999/2000 (Baldwin

et al.,

2003) and continued until 2009 during which time 800-1,500 loggerheads were estimated to nest annually on Dirk Hartog Island beaches (Baldwin

et al.,

2003).

Fewer loggerheads (approximately 150-350 per season) are reported nesting on the Muiron Islands; however, more nesting loggerheads are reported here than on North West Cape (approximately 50-150 per season) (Baldwin

et al.,

2003). Although data are insufficient to determine trends, historical information suggests the nesting population in the Muiron Islands and North West Cape region was likely reduced from historical numbers, before recent beach monitoring programs began, as a result of bycatch in commercial fisheries (Nishemura and Nakahigashi, 1990; Poiner

et al.,

1990; Poiner and Harris, 1996).

Southwest Indian Ocean DPS

In the Southwest Indian Ocean, the highest concentration of nesting occurs on the coast of Tongaland, South Africa, where surveys and management practices were instituted in 1963 (Baldwin

et al.,

2003). A trend analysis of index nesting beach data from this region from 1965 to 2008 indicates an increasing nesting population between the first decade of surveys, which documented 500-800 nests annually, and the last 8 years, which documented 1,100-1,500 nests annually (Nel, 2008). These data represent approximately 50 percent of all nesting within South Africa and are believed to be representative of trends in the region. Loggerhead nesting occurs elsewhere in South Africa, but sampling is not consistent and no trend data are available. The total number of females nesting annually in South Africa is estimated between 500-2,000 turtles (Baldwin

et al.,

2003). In Mozambique, surveys have been instituted much more recently; likely less than 200 females nest annually and no trend data are available (Baldwin

et al.,

2003; Louro

et al.,

2006; Videira

et al.,

2008, 2010; Pereira

et al.,

2009). Similarly, in Madagascar, loggerheads have been documented nesting in low numbers, but no trend data are available (Rakotonirina, 2001).

Northwest Atlantic Ocean DPS

Nesting occurs within the Northwest Atlantic along the coasts of North America, Central America, northern South America, the Antilles, and The Bahamas, but is concentrated in the southeastern U.S. and on the Yucatan Peninsula in Mexico (Sternberg, 1981; Ehrhart, 1989; Ehrhart

et al.,

2003; NMFS and USFWS, 2008). Collectively, the Northwest Atlantic Ocean hosts the most significant nesting assemblage of loggerheads in the western hemisphere and is one of the two largest loggerhead nesting assemblages in the world. NMFS and USFWS (2008), Witherington

et al.

(2009), and TEWG (2009) provide comprehensive analyses of the status of the nesting assemblages within the Northwest Atlantic Ocean DPS using standardized data collected over survey periods ranging from 10 to 23 years. The results of these analyses, using different analytical approaches, were consistent in their findings—there had been a significant, overall nesting decline

within this DPS. However, with the addition of nesting data from 2008 through 2010, which was not available at the time those analyses were conducted, the final result for the trend line changes. Nesting in 2008 showed a substantial increase compared to the low of 2007, and nesting in 2010 reached the highest level seen since 2000 (Florida Fish and Wildlife Conservation Commission Core Index Nesting Beach Database). The most current nesting trend for the Northwest Atlantic Ocean DPS, from 1989-2010, is very slightly negative, but the rate of decline is not statistically different from zero. Additionally, the range from the statistical analysis of the nesting trend includes both negative and positive growth (NMFS, unpublished data).

NMFS and USFWS (2008) identified five recovery units (nesting subpopulations) in the Northwest Atlantic Ocean: The Northern (Florida/Georgia border to southern Virginia); Peninsular Florida (Florida/Georgia border south through Pinellas County, excluding the islands west of Key West, Florida); Dry Tortugas (islands west of Key West, Florida); Northern Gulf of Mexico (Franklin County, Florida, west through Texas); and Greater Caribbean (Mexico through French Guiana, The Bahamas, Lesser and Greater Antilles). At that time, declining trends in the annual number of nests were documented for all recovery units for which there were an adequate time series of nesting data.

The Peninsular Florida Recovery Unit represents approximately 87 percent of all nesting effort in the Northwest Atlantic Ocean DPS (Ehrhart

et al.,

2003). A significant declining trend had been documented for the Peninsular Florida Recovery Unit, where nesting declined 26 percent over the 20-year period from 1989-2008, and declined 41 percent over the period 1998-2008 (NMFS and USFWS, 2008; Witherington

et al.,

2009). As explained previously, with the addition of nesting data through 2010, the nesting trend for the Peninsular Florida Recovery Unit, and the Northwest Atlantic Ocean DPS, does not show a nesting decline statistically different from zero. The Northern Recovery Unit is the second largest recovery unit within the DPS and was declining significantly at 1.3 percent annually from 1983 to 2007 (NMFS and USFWS, 2008). Currently, nesting for that recovery unit is showing possible signs of stabilizing. In 2008, nesting in Georgia reached what was a new record at that time (1,646 nests), with a downturn in 2009, followed by yet another record in 2010 (1,760 nests). South Carolina had the two highest years of nesting in the 2000s in 2009 (2,183 nests) and 2010 (3,141 nests). The previous high for that 11-year span was 1,433 nests in 2003. North Carolina had 847 nests in 2010, which is above the average of 715. The Georgia, South Carolina, and North Carolina nesting data come from the

seaturtle.org

Sea Turtle Nest Monitoring System which is populated with data input by the State agencies. The Greater Caribbean Recovery Unit is the third largest recovery unit within the Northwest Atlantic Ocean DPS, with the majority of nesting at Quintana Roo, Mexico. TEWG (2009) reported a greater than 5 percent annual decline in loggerhead nesting from 1995-2006 at Quintana Roo. When nest counts up through 2010 are analyzed, however, the nesting trends from 1989 through 2010 are not significantly different from zero for all of the recovery units within the Northwest Atlantic Ocean DPS for which there are enough data to analyze (NMFS, unpublished data).

In an effort to evaluate loggerhead population status and trends beyond the nesting beach, NMFS and USFWS (2008) and TEWG (2009) reviewed data from in-water studies within the range of the Northwest Atlantic Ocean DPS. NMFS and USFWS (2008), in the Recovery Plan for the Northwest Atlantic Population of the Loggerhead Sea Turtle, summarized population trend data reported from nine in-water study sites where loggerheads were regularly captured and where efforts were made to provide local indices of abundance. These sites were located from Long Island Sound, New York, to Florida Bay, Florida. The study periods for these nine sites varied. The earliest began in 1987, and the most recent were initiated in 2000. Results reported from four of the studies indicated no discernible trend, two studies reported declining trends, and two studies reported increasing trends. Trends at one study site, Mosquito Lagoon, Florida, indicated either a declining trend (all data, 1977-2005) or no trend (more recent data, 1995-2005), depending on whether all sample years were used or only the more recent, and likely more comparable sample years, were used. TEWG (2009) used raw data from six of the aforementioned nine in-water study sites to conduct trend analyses. Results from three of the four sites located in the southeastern United States showed an increasing trend in the abundance of loggerheads, one showed no discernible trend, and the two sites located in the northeastern United States showed a decreasing trend in abundance of loggerheads.

Crouse

et al.

(1987) and Crowder

et al.

(1994) presented models, using data available from what is now the Northwest Atlantic Ocean DPS, suggesting that adults (males and females) are approximately 0.3 percent of the total population. These models assume that the population is density independent and growing exponentially; however, in the case of sea turtles, it is unlikely that either of these assumptions is met. The most recent point estimate of the number of adult females in the Northwest Atlantic Ocean DPS is 30,000 (Southeast Fisheries Science Center, 2009); assuming a 1:1 adult sex ratio results in 60,000 adults. If those individuals represent 0.3 percent of the total population size, then the total population size would be on the order of 20 million individuals. The vast majority of these individuals would be in the youngest life stages, where natural mortality is very high. This is the life history strategy of sea turtles; many individuals must be produced to contribute to the breeding population and to keep the population from declining. The most important point to understand regarding these models and subsequent calculations is that their main assumptions—the population has a stable age distribution, anthropogenic mortality is constant, sex ratios are equal, and the environment is constant—are likely not met.

A recent aerial survey from Cape Canaveral, Florida, to the mouth of the Gulf of St. Lawrence provided insight into loggerhead abundance in continental shelf waters of the U.S. Atlantic coast. In a preliminary report (Northeast Fisheries Science Center, 2011), the most conservative estimate, in which only sightings that were positively identified as loggerhead sea turtles were used, was that about 588,000 juvenile and adult loggerheads were present in the survey area (approximate inter-quartile range of 382,000-817,000 individuals). When a portion of the unidentified turtles were assigned as loggerheads, the estimate increased to 801,000 individuals (inter-quartile range of 521,000-1,111,000). The survey effort did not encompass waters south of Cape Canaveral on the Atlantic Coast or in the Gulf of Mexico (Northeast Fisheries Science Center, 2011).

Northeast Atlantic Ocean DPS

In the northeastern Atlantic, the Cape Verde Islands support the only large nesting population of loggerheads in the region (Fretey, 2001). Nesting occurs at some level on most of the islands in the archipelago with the largest nesting

numbers reported from the island of Boa Vista where studies have been ongoing since 1998 (Lazar and Holcer, 1998; López-Jurado

et al.,

2000; Fretey, 2001; Varo Cruz

et al.,

2007; Loureiro, 2008; M. Tiwari, NMFS, personal communication, 2008). On Boa Vista Island, 833 and 1,917 nests were reported in 2001 and 2002 respectively from 3.1 km of beach (Varo Cruz

et al.,

2007) and between 1998 and 2002 the local project had tagged 2,856 females (Varo Cruz

et al.,

2007). In 2005, 5,396 nests and 3,121 females were reported from 9 km of beach on Boa Vista Island (López-Jurado

et al.,

2007). More recently, 12,028 nests in 2008, 20,102 nests in 2009, and 9,174 nests in 2010 were reported from approximately 68 km of beach on Boa Vista Island (Cabo Verde Natura 2000, 2010). On Sal Island, 344 nests were reported in 2008, 1,037 nests in 2009, and 566 nests in 2010 (SOS Tartarugas, 2009; J. Cozens, SOS Tartarugas, personal communication, 2011). From Santiago Island, 66 nests were reported from four beaches in 2007 and 53 nests from five beaches in 2008 (

http://tartarugascaboverde.wordpress.com/santiago

). Due to limited data available, a population trend cannot currently be determined for the Cape Verde population; however, available information on the directed killing of nesting females suggests that this nesting population is under severe pressure and likely significantly reduced from historical levels (Marco

et al.,

2010). Loureiro (2008) reported a reduction in nesting from historical levels at Santiago Island, based on interviews with elders. Elsewhere in the northeastern Atlantic, loggerhead nesting is non-existent or occurs at very low levels. In Morocco, anecdotal reports indicated high numbers of nesting turtles in southern Morocco (Pasteur and Bons, 1960), but a few recent surveys of the Atlantic coastline have suggested a dramatic decline (Tiwari

et al.,

2001, 2006). A few nests have been reported from Mauritania (Arvy

et al.,

2000) and Sierra Leone (E. Aruna, Conservation Society of Sierra Leone, personal communication, 2008). Some loggerhead nesting in Senegal and elsewhere along the coast of West Africa has been reported; however, a more recent and reliable confirmation is needed (Fretey, 2001).

Mediterranean Sea DPS

Nesting occurs throughout the central and eastern Mediterranean in Italy, Greece, Cyprus, Turkey, Syria, Lebanon, Israel, Egypt, Libya, and Tunisia (Sternberg, 1981; Margaritoulis

et al.,

2003; SWOT, 2007; Casale and Margaritoulis, 2010). In addition, sporadic nesting has been reported from the western Mediterranean (Spain and France), but the vast majority of nesting occurs in Greece and Turkey (Margaritoulis

et al.,

2003). The documented annual nesting of loggerheads in the Mediterranean averages over 7,200 nests (Casale and Margaritoulis, 2010). There has been no discernible trend in nesting reported for the two longest monitoring projects in Greece, Laganas Bay (Margaritoulis, 2005) and southern Kyparissia Bay (Margaritoulis and Rees, 2001). However, the nesting trend at Rethymno Beach, which hosts approximately 7 percent of all documented loggerhead nesting in the Mediterranean, showed a highly significant declining trend from 1990 through 2004 (Margaritoulis

et al.,

2009). In Turkey, intermittent nesting surveys have been conducted since the 1970s with more consistent surveys conducted on some beaches only since the 1990s, making it difficult to assess trends in nesting. Ilgaz

et al.

(2007) reported a declining trend at Fethiye Beach from 1993-2004, this beach represents approximately 10 percent of loggerhead nesting in Turkey (Margaritoulis

et al.,

2003).

South Atlantic Ocean DPS

In the South Atlantic, nesting occurs primarily along the mainland coast of Brazil from Sergipe south to Rio de Janeiro, with peak concentrations in northern Bahia, Espírito Santo, and northern Rio de Janeiro with peak nesting along the coast of Bahia (Marcovaldi and Chaloupka, 2007). Prior to 1980, loggerhead nesting populations in Brazil were considered severely depleted. Recently, Marcovaldi and Chaloupka (2007) reported a long-term, sustained increasing trend in nesting abundance over a 16-year period from 1988 through 2003 on 22 surveyed beaches containing more than 75 percent of all loggerhead nesting in Brazil. A total of 4,837 nests were reported from these survey beaches for the 2003-2004 nesting season (Marcovaldi and Chaloupka, 2007). Loggerhead nesting has continued to increase with approximately 6,800 nests recorded during the 2008-2009 nesting season (dos Santos

et al.,

2011).

Summary of Comments

With the publication of the proposed listing determination for the nine loggerhead sea turtle DPSs on March 16, 2010 (75 FR 12598), we announced a 90-day comment period extending through June 14, 2010. On June 2, 2010 (75 FR 30769), we extended the public comment period for an additional 90 days through September 13, 2010, and announced our intention to hold a public hearing to provide an additional opportunity and format to receive public input. The public hearing was held in Berlin, Maryland, on June 16, 2010. On March 22, 2011 (76 FR 15932), we published in the

Federal Register

a notice announcing a 6-month extension of the deadline for a final listing decision to address substantial disagreement that existed 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 announced an additional 20-day comment period for new information or analyses from the public that would help clarify this issue.

A joint NMFS/USFWS policy requires us to solicit independent expert review from at least three qualified specialists, concurrent with the public comment period (59 FR 34270; July 1, 1994). In December 2004, the Office of Management and Budget (OMB) issued a Final Information Quality Bulletin for Peer Review establishing minimum peer review standards, a transparent process for public disclosure, and opportunities for public input. The OMB Peer Review Bulletin, implemented under the Information Quality Act (Public Law 106-554), is intended to provide public oversight on the quality of agency information, analyses, and regulatory activities, and applies to information disseminated on or after June 16, 2005. We solicited technical review of the proposed listing determination from six independent experts, and received reviews from all six of these experts. The independent expert review under the joint NMFS/USFWS peer review policy collectively satisfies the requirements of the OMB Peer Review Bulletin and the joint NMFS/USFWS peer review policy. The peer reviewers provided additional information, clarifications, suggestions, and editorial comments to improve this final rule. Peer reviewer comments are addressed in the following summary and incorporated into this final rule as appropriate.

The Services received over 109,000 public comments on the proposed rule, of which over 104,000 were form letters sent as part of comment campaigns from environmental organizations. Approximately 5,000 unique individual comments received were generally supportive of the proposed rule. Comments were received from interested individuals, State and Federal agencies, fishing groups, environmental

organizations, industry groups, and peer reviewers with scientific expertise.

The Services received many comments outside the scope of this rulemaking. These included comments on agency guidance on listing species, prohibitions on take, exceptions to the ESA prohibition on take (

e.g.,

incidental take permits under section 10, incidental take statements under section 7), the difference between “take” as defined by the ESA and mortality, actions that may be taken as a result of changes to the ESA listing for loggerheads, management measures implemented via subsequent rulemakings, the findings of a National Research Council report on the assessment of sea turtle status and trends, and implementation of recovery plans. We do not respond to these comments in this final rule.

The summary of comments and our responses below are organized into six general categories: (1) Peer review comments; (2) comments on the identification of DPSs; (3) comments on the identification and consideration of specific threats; (4) comments on the status and trends and extinction risk assessments of the DPSs; (5) comments on the status determinations for the DPSs; and (6) other comments.

Peer Review Comments

Comment 1:

Two of the six peer reviewers requested clearer definitions for Endangered Species Act terminology used in the proposed rule. For instance, the proposed rule stated “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 * * *” These two reviewers asked about the time frame for “in danger of extinction” and whether the term extinction is referring to quasi-extinction or absolute extinction. One of these reviewers also asked what is meant by a “significant portion of its range” and “foreseeable future.”

Response:

The ESA defines an endangered species as a species that is “in danger of extinction throughout all or a significant portion of its range,” and a threatened species as a species that is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” The legislative history of the ESA indicates Congress did not provide any quantitative measures for the Services to apply when determining whether a species is “in danger of extinction.” Rather, it left to the discretion of the Services the task of giving meaning to the terms through the process of case-specific analyses that necessarily depend on the Services' expertise to make the highly fact-specific decisions to list species as endangered or threatened. Although Congress did not seek to make any single factor controlling when drawing the distinction, Congress acknowledged that “there is a temporal element to the distinction between the categories.”

In Re Polar Bear Endangered Species Act Listing and § 4(d) Rule Litigation,

Slip Opinion at 40 n. 24, 51, 51 n. 27. (D.D.C. June 30, 2011). Thus, in the context of the ESA, the Services interpret an “endangered species” to be one that is presently at risk of extinction. A “threatened species,” on the other hand, is not currently at risk of extinction, but is likely to become so. In other words, a key statutory difference between a threatened and endangered species is the timing of when a species may be in danger of extinction, either now (endangered) or in the foreseeable future (threatened).

The term “significant portion of its range” is not defined by the statute. For the purposes of this rule, a portion of the species' (species, subspecies, or distinct population segment) range is “significant” if its contribution to the viability of the species is so important that, without that portion, the species would be in danger of extinction. The definition of a “threatened species” is a species that is “likely to become an endangered species within the foreseeable future.” USFWS uses the term foreseeable future as interpreted by the U.S. Department of the Interior Office of the Solicitor (Bernhardt, 2009): “In summary, the foreseeable future describes the extent to which the Secretary (of Interior) can, in making determinations about the future conservation status of the species, reasonably rely on predictions about the future. Those predictions can be in the form of extrapolation of population or threat trends, analysis of how threats will affect the status of the species, or events that will have a significant new impact on the species. The Secretary's ability to rely on predictions may significantly vary with the amount and substance of available data.”

Comment 2:

Three of the six peer reviewers agreed with the designation of the nine proposed DPSs. Two reviewers agreed with eight of the proposed DPSs, but disagreed with the proposed North Indian Ocean DPS and questioned the rationale for not breaking out this DPS into East and West components. One reviewer felt that the separation of the Indian Ocean into three DPSs was not sufficiently explained. Another reviewer found the evidence compelling to conclude that the North Pacific Ocean, South Pacific Ocean, and South Atlantic Ocean DPSs were discrete. However, he had questions about the discreteness of the Indian Ocean DPSs, and the northern Atlantic Ocean and Mediterranean Sea DPSs. While he did not question the discreteness findings of these DPSs, the full argument was not clear to him.

Response:

Insufficient information was available to further separate the North Indian Ocean DPS into east and west segments. As for the comments indicating that sufficient information was not provided to justify the separation of some of the DPSs, the Services believe the information provided in the Discreteness Determination section of this final rule and the Discreteness Determination section of the Status Review (Conant

et al.,

2009), which is incorporated into this final rule by reference, meets agency policy for identifying DPSs.

Comment 3:

In most cases, the peer reviewers either agreed with or did not oppose the proposed listing status for the nine DPSs. However, one reviewer stated that while he does not oppose the proposed status for any of the DPSs, he does not believe the proposed status for each DPS was adequately explained or justified. Another reviewer expressed similar concerns for the North Pacific Ocean DPS, South Pacific Ocean DPS, North Indian Ocean DPS, Southeast Indo-Pacific Ocean DPS, and the Northwest Atlantic Ocean DPS and stated that the status determinations needed to be more explicitly justified. One reviewer expressed concern about the restricted use of nesting data for the South Pacific Ocean DPS up until 1999 only and indicated that more recent data should be used. This reviewer indicated that the more recent data for Mon Repos, for example, have shown increased nesting with 2009 nesting levels back up to similar numbers as seen in the 1990s. Two reviewers did not believe sufficient data were presented to justify listing of the North Indian Ocean DPS as endangered, particularly in light of the large size of the nesting population, although one of them indicated he did not feel strongly about this. These same two reviewers also questioned the proposed endangered status for the Southeast Indo-Pacific Ocean DPS because the nesting population is protected, trends have been stable, and there do not appear to be major sources of mortality; however, one of the two reviewers indicated he did not feel strongly about this.

Response:

With regard to the North Indian Ocean DPS, threats are substantial as identified in the five-factor review, and conservation efforts are embryonic relative to the known and suspected threats impacting the population. Given the information suggesting declines in the nesting population, the emergence of gillnet fisheries in close proximity to the nesting beaches, and the embryonic stage of conservation efforts in the region, the Services believe an endangered status is justified. In the case of the Southeast Indo-Pacific Ocean DPS, the nesting survey effort and methods have varied over the last 2 decades and currently there are no nesting population estimates available to suggest any positive trend in nesting populations. However, some of the fisheries bycatch impacts have been resolved through requirement of turtle excluder devices (TEDs) in shrimp trawlers, and longline fishery effort has declined due to fish stock decreases and economic reasons. Although a new fisheries effort has emerged for portunid crabs and is posing new threats to loggerheads, and longline fishing effort for tuna and billfish is also subject to increase if and when economics and fish populations improve, we are unable to quantify these threats. As a result, based primarily on peer reviewer comments regarding current threats and conservation efforts, the Services now believe a threatened status for the Southeast Indo-Pacific Ocean DPS is appropriate. With regard to the comment that the status determinations for several of the DPSs lacked sufficient justification, we have clarified the rationale for the status determinations in the Finding section in this final rule.

Comment 4:

One peer reviewer commented that the information presented in the proposed rule appeared thorough, up-to-date, and convincing for the conclusions made, both with respect to DPS designation and listing status. However, he noted the Services could have readily arrived at these conclusions without the use of either the susceptibility to quasi-extinction (SQE) or the threat matrix analysis. He also noted that the relative novelty and thin track records of both methods may draw criticism that distracts from the real substance of the analysis of the available data. Another reviewer noted weaknesses with the extinction risk assessments, but was pleased to see these quantitative risk assessments included in the proposed rule and appreciated that they were considered hand-in-hand with the threats analysis. Specifically, he stated that the SQE approach looked at the risk of declining to 30 percent of the current population size, but it was not clear over what time frame this decline was examined or what risk of decline warranted listing. He also noted that the SQE method was largely retrospective, as it used past empirical trends to forecast future trends. He thought the matrix method was better at exploring the potential risk posed by future trends, so it was more forward-looking than the SQE method, but it only looked at deterministic risk, not stochastic risk. A third reviewer agreed with the threat based assessments, but he thought details were lacking in the SQE analysis. Specifically, he thought there should be more emphasis on the relationship between reduced population sizes and decreased resilience to cope with current and future impacts and felt this to be particularly relevant given the large time frames for maturity and the large spatial scales involved.

Response:

The Services have clarified the text in the Extinction Risk Assessments section to more clearly state that the SQE and threat matrix analyses were only used to provide some additional insights into the status of the nine DPSs, but that ultimately the conclusions and determinations made were based on an assessment of population sizes and trends, current and anticipated threats (

i.e.,

five-factor analysis), and conservation efforts for each DPS.

Comment 5:

One peer reviewer stated that the threats assessments were not as future-focused as he would have liked. He thought they tended to rely on current or past status and trends, but he believes the ESA is forward-looking and is concerned about the future status of the species. He recognized that some evidence was presented about future trends, such as development pressures on beaches in various areas of the world, progress toward enforcing existing legislation, reduction of bycatch, and potential climate change impacts, but he still thought the final assessments could be more future-focused.

Response:

Section 4 of the ESA and its implementing regulations (50 CFR part 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be endangered or threatened due to one or more of the five factors described in section 4(a)(1) of the Act. The Services are required to use the best scientific and commercial information available at the time we are making our listing assessments. Thus, predicting potential future threats to a species is dependent on available data and the life history and ecology of the species, the nature of the threats, and the species' response to those threats. While the SQE analysis relied on nesting beach surveys and is retrospective, the threat matrix analyses look at the potential future directions given the known threats and loggerhead sea turtle biology. Although the SQE and threat matrix analyses provided some additional insights into the status of the nine DPSs, ultimately the conclusions and determinations made were primarily based on an assessment of population sizes and trends, current and anticipated threats, and conservation efforts for each DPS.

Comment 6:

One peer reviewer said that for some populations (

e.g.,

Northwest Atlantic Ocean DPS) there has been a great deal of study over the past few decades and there is a lot of information about many aspects of the life history of the population and its anthropogenic threats. For other populations, there are little data. As a result he was unclear how the quality of the empirical evidence affected the risk assessment and the status classification under the ESA. He questioned whether a more precautionary interpretation of the risk was taken when there was greater uncertainty or whether the greater amount of evidence in some places actually made it easier.

Response:

We are to make status determinations 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. In assessing the status of each identified DPS, we considered available information on status and trends, the five-factor analysis (see Summary of Factors Affecting the Nine Loggerhead DPSs section), and conservation efforts that have been implemented (see Conservation Efforts section). We considered this information in light of the ESA definitions of endangered and threatened (see Listing Determinations Under the ESA section).

Comment 7:

One peer reviewer commented that the boundary of 139° E. long. in the Gulf of Carpentaria separating the South Pacific Ocean DPS and the Southeast Indo-Pacific Ocean DPS was too far west. He stated that satellite tracking showed a female from Western Australia moving into 141° E. long. and indicated there are reasonable numbers of loggerheads foraging in the Torres Strait for which genetic analyses have not yet been conducted.

Response:

Based on the information provided by this peer reviewer, the

Services have revised the boundary separating the South Pacific Ocean DPS and the Southeast Indo-Pacific Ocean DPS from 139° E. long. to 141° E. longitude.

Comments on the Identification of DPSs

Comment 8:

Two commenters questioned the Services' application of the DPS policy. They noted that DPS designations should be used sparingly and only when biological evidence indicates that such action is warranted to meet Congressional intent. They stated that the separation must be marked, and DPS designations are only appropriate where scientific evidence is conclusive to justify such listing.

Response:

The Services acknowledge in the Policies for Delineating Species Under the ESA section of this final rule that Congress has instructed the Secretaries of the Interior and Commerce to exercise the authority to designate DPSs “* * * sparingly and only when the biological evidence indicates such action is warranted.” As a result, the Services adopted a joint policy for recognizing DPSs under the ESA (DPS Policy; 61 FR 4722) on February 7, 1996. This policy, described in the Policies for Delineating Species Under the ESA section, has been closely followed in determining loggerhead DPSs, and the Services believe it meets the Congressional intent.

Comment 9:

One commenter did not believe additional benefits to the populations would occur if DPSs were designated (

e.g.,

threatened turtles are already treated the same as endangered turtles under a 4(d) rule, critical habitat can be designated, and section 7 of the ESA applies). Another commenter believes the United States will diminish its role in international sea turtle conservation by only having an interest in the two DPSs (Northwest Atlantic Ocean and North Pacific Ocean) that occur in the United States.

Response:

The Services were petitioned to list the Northwest Atlantic and North Pacific loggerhead sea turtle populations as DPSs and to change the listing status of turtles in those populations from threatened to endangered. The Services do not believe that identifying DPSs for the loggerhead will diminish the United States' role in international sea turtle conservation. Both Services have strong international programs for sea turtles, including implementation of the U.S. Marine Turtle Conservation Act of 2004, which was created to assist in the conservation of sea turtles and their nesting habitats in foreign countries.

Comment 10:

The State of Florida supports the identification of nine DPSs. The States of Georgia and South Carolina support the designation of the Northwest Atlantic DPS. The State of Connecticut believes the listing of nine loggerhead DPSs is reasonable and will result in better targeted conservation for this species. The State of Maryland believes it is premature to consider listing DPSs without full disclosure of loggerhead population status. Numerous conservation organizations and individuals, including all the individuals that sent form letters, support designation of the nine proposed DPSs. Three fishing groups do not support the identification of loggerhead DPSs.

Response:

The Services have considered the best available information on loggerhead population status and have summarized this information in the Status and Trends of the Nine Loggerhead DPSs section of this final rule.

Comment 11:

The State of Alaska provided information that only two loggerheads have been observed in Alaska in the past 50 years and requested that Alaska waters be excluded from the North Pacific Ocean DPS.

Response:

While the ESA authorizes the listing, delisting, or reclassification of a species, subspecies, or DPS of a vertebrate species, it does not authorize the exclusion of a subset or portion of a listed species, subspecies, or DPS from a listing decision. Although only two observations of loggerheads in Alaska waters have been reported, this indicates the species does at least occasionally occur there.

Comment 12:

One commenter contend

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