Protected species listed under the Endangered Species Act and known to occur in waters around the Hawaii Archipelago include green, hawksbill, leatherback, loggerhead and olive ridley sea turtles, humpback, sperm, blue, fin and sei whales, Hawaiian monk seals, short-tailed albatrosses and Newell’s shearwaters. Other marine mammals known to occur include several types of dolphins and whales, other seabirds known to occur include shearwaters, petrels, boobies, tropicbirds and other species.
Green Sea Turtles (Chelonia mydas)
Green turtles in Hawaii are considered genetically distinct and geographically isolated, although a nesting population at Islas Revillagigedos in Mexico appears to share the mtDNA haplotype that commonly occurs in Hawaii. In Hawaii, green turtles nest on six small sand islands at French Frigate Shoals, a crescent-shaped atoll situated in the Northwestern Hawaiian Islands. Ninety to 95 percent of the nesting and breeding activity occurs at the French Frigate Shoals, and at least 50 percent of that nesting takes place on East Island, a 12-acre island. Low-level nesting also occurs at Laysan Island, Lisianski Island, and on Pearl and Hermes Reef. Since the establishment of the ESA in 1973, and following years of exploitation, the nesting population of Hawaiian green turtles has shown a gradual but definite increase. In three decades, the number of nesting females at East Island increased from 67 nesting females in 1973 to 467 nesting females in 2002. Nester abundance increased rapidly at this rookery during the early 1980s, leveled off during the early 1990s, and again increased rapidly during the late 1990s to the present. Scientists have determined that the Hawaiian green sea turtle stock is well on the way to recovery following 25 years of protection. This increase is attributed to increased female survivorship since the harvesting of turtles was prohibited in addition to the cessation of habitat damage at the nesting beaches since the early 1950s.
Hawksbill Sea Turtles (Eretmochelys imbricata) [top]
Along the far western and southeastern Pacific, hawksbill turtles nest on the islands and mainland of southeast Asia, from China to Japan, and throughout the Philippines, Malaysia, Indonesia, Papua New Guinea, the Solomon Islands, and Australia. Hawksbill turtles occur in waters around the Hawaii Archipelago and nest on Maui and the southeast coast of the Big Island.
Leatherback Sea Turtles (Dermochelys coriacea) [top]
Migratory routes of leatherback turtles originating from eastern and western Pacific nesting beaches are not entirely known. However, satellite tracking of postnesting females and genetic analyses of leatherback turtles caught in U.S. Pacific fisheries or stranded on the west coast of the U.S. presents some strong insights into at least a portion of their routes and the importance of particular foraging areas. Current data from genetic research suggest that Pacific leatherback stock structure may vary by region. Due to the fact that leatherback turtles are highly migratory and that stocks mix in high-seas foraging areas, and based on genetic analyses of samples collected by both Hawaii-based and west-coast-based longline fishery observers, leatherback turtles inhabiting the northern and central Pacific Ocean comprise individuals originating from nesting assemblages located south of the equator in the western Pacific (e.g. Indonesia, Solomon Islands) and in the eastern Pacific along the Americas (e.g. Mexico, Costa Rica). Recent information on leatherbacks tagged off the west coast of the United States has also revealed an important migratory corridor from central California to south of the Hawaiian Islands, leading to western Pacific nesting beaches.
Loggerhead Sea Turtles (Caretta caretta)
Loggerheads in the North Pacific are opportunistic feeders that target items floating at or near the surface, and if high densities of prey are present, they will actively forage at depth. As they age, loggerheads begin to move into shallower waters, where, as adults, they forage over a variety of benthic hard- and soft-bottom habitats. Subadults and adults are found in nearshore benthic habitats around southern Japan, as well as in the East China Sea and the South China Sea (e.g. Philippines, Taiwan, and Vietnam). In the South Pacific an estimated 3,000 loggerheads were reported to nest annually in Queensland, Australia during the late 1970s. However, long-term trend data from Queensland indicate a 50 percent decline in nesting by 1988–89 due to incidental mortality of turtles in the coastal trawl fishery. This decline is corroborated by studies of breeding females at adjacent feeding grounds. Currently, approximately 300 females nest annually in Queensland, mainly on offshore islands (Capricorn-Bunker Islands, Sandy Cape, Swains Head). In southern Great Barrier Reef waters, nesting loggerheads have declined approximately 8 percent per year since the mid-1980s (Heron Island), while the foraging ground population has declined 3 percent and comprised less than 40 adults by 1992. Researchers attribute the declines to recruitment failure due to fox predation of eggs in the 1960s and mortality of pelagic juveniles from incidental capture in longline fisheries since the 1970s.
Olive Ridley Sea Turtles (Lepidochelys olivacea)
Historically, an estimated 10-million olive ridleys inhabited the waters in the eastern Pacific off Mexico. However, human-induced mortality led to declines in this population. Beginning in the 1960s, and lasting over the next 15 years, several million adult olive ridleys were harvested by Mexico for commercial trade with Europe and Japan (NMFS and USFWS 1998e). Although olive ridley meat is palatable, it is not widely sought; eggs, however, are considered a delicacy, and egg harvest is considered one of the major causes for its decline. Fisheries for olive ridley turtles were also established in Ecuador during the 1960s and 1970s to supply Europe with leather. In the Indian Ocean, Gahirmatha supports perhaps the largest nesting population; however, this population continues to be threatened by nearshore trawl fisheries. Direct harvest of adults and eggs, incidental capture in commercial fisheries, and loss of nesting habits are the main threats to the olive ridley’s recovery.
Humpback Whales (Megaptera novaeangliae)
Humpback whales migrate through waters around the NWHI and occur off all eight Hawaiian Islands during the winter breeding season, but particularly within the shallow waters of the “four-island” region (Kaho’olawe, Molokai, Lanai, Maui); the northwestern coast of the island of Hawaii; and the waters around Niihau, Kauai, and Oahu. This population is estimated to total 6,000 – 10,000 individuals and researchers estimate that it is increasing by seven percent per year, putting the species on a track to double in just over a decade.
Sperm Whales (Physeter macrocephalus)
Sperm whales are found in tropical to polar waters throughout the world and are among the most abundant large cetaceans in the region. Sperm whales have been sighted around several of the Northwestern Hawaiian Islands and off the main islands of Hawaii. The sounds of sperm whales have been recorded throughout the year off Oahu.
Blue whales (Balaenoptera musculus)
No sightings or strandings of blue whales have been reported in Hawaii, but acoustic recordings made off Oahu and Midway Atoll has reported blue whales somewhere within the EEZ around Hawaii.
Fin Whales (Balaenoptera physalus)
Fin whales are found throughout all oceans and seas of the world from tropical to polar latitudes. Although it is generally believed that fin whales make poleward feeding migrations in summer and move toward the equator in winter, few actual observations of fin whales in tropical and subtropical waters have been documented, particularly in the Pacific Ocean away from continental coasts. There have only been a few sightings of fin whales in Hawaii waters.
Sei Whales (Balaenoptera borealis)
Sei whales have a worldwide distribution but are found mainly in cold temperate to subpolar latitudes rather than in the tropics or near the poles. They are distributed far out to sea and do not appear to be associated with coastal features. Sei whales are rare in Hawaii waters.
Hawaiian Monk Seals (Monachus schauinslandi)
The Hawaiian monk seal is a tropical seal endemic to the Hawaiian Islands. Today, the entire population of Hawaiian monk seals is about 1,300 to 1,400 and occurs mainly in the NWHI. The six major reproductive sites are French Frigate Shoals, Laysan Island, Lisianski Island, Pearl and Hermes Reef, Midway Atoll, and Kure Atoll. Small populations at Necker Island and Nihoa Island are maintained by both reproduction and immigration, and an increasing number of seals are distributed throughout the MHI where they are also reproducing. The 2004 U.S. Pacific Marine Mammal Stock Assessment estimates that there are 1,304 monk seals in the Hawaiian Islands, with at least 52 of those occurring in the Main Hawaiian Islands (NOAA 2005). There was an exceptional reporting of a pupping at Johnston Atoll in 1969; however, site visits by biologists have been infrequent and it is not known how regularly monk seals use the atoll. Aggressive male monk seals in the NWHI are known to mob females and sometimes kill pups. Mobbing behavior is thought to occur due to a skewed sex ratio, and 22 subadult males were translocated from Laysan Island in the NWHI to the Big Island in the MHI in 1994. In 1998, two males were identified as aggressive at French Frigate Shoals. They were translocated to Johnston Atoll in 1999 and were resighted at that location for a few months, although they have not been resighted recently. At one time it was believed that NWHI lobsters were an important part of the diet of monk seals and this concern may have contributed to the closure of the NWHI lobster fishery. However an ongoing analysis by NMFS of fatty acid signatures in monk seal blubber indicates that lobster and crustaceans in general don’t appear to be very important to monk seals as there are species of NWHI lobsters in relatively high abundance but monk seals are not eating them.
Other Marine Mammals
Non-ESA Listed Marine Mammals
Blainsville beaked whale
Pygmy sperm whale
Cuvier’s beaked whale
Short-finned pilot whale
Dwarf sperm whale
False killer whale
Pacific white-sided dolphin
Pygmy killer whale
Longman’s beaked whale
Short-tailed albatrosses (Phoebastria immutabilis)
The short-tailed albatross is the largest seabird in the North Pacific, with a wingspan of more than 3 meters (9 ft) in length. The short-tailed albatross is known to breed only in the western North Pacific Ocean, south of the main islands of Japan. Although at one time there may have been more than ten breeding locations, today there are only two known active breeding colonies: Minami Tori Shima Island and Minami-Kojima Island. On December 14, 2000, one short-tailed albatross was discovered incubating an egg on Yomejima Island of the Ogasawara Islands (southernmost island among the Mukojima Islands). A few short-tailed albatrosses have also been observed attempting to breed, although unsuccessfully, at Midway Atoll in the NWHI. The 2008 worldwide population is estimate at 2,771 individuals and based on breeding pair counts, appears to be increasing by seven percent annually.
Newell’s Shearwater (Puffinus auricularis newelli)
Generally, the at-sea distribution of the Newell’s shearwater is restricted to the waters surrounding the Hawaii Archipelago, with preference given to the area east and south of the main Hawaiian Islands. The Newell’s shearwater breeds only in colonies on the main Hawaiian Islands where it is threatened by urban development and introduced predators like rats, cats, dogs, and mongooses. Shearwaters are most active in the day and skim the ocean surface while foraging. During the breeding season, shearwaters tend to forage within 50–62 miles (80–100 km) of their nesting burrows. Shearwaters also tend to be gregarious at sea, and the Newell’s shearwater is known to occasionally follow ships.
Other seabirds found in the region include the black-footed albatross (Phoebastria nigripes), Laysan albatross (Phoebastria immutabilis), masked booby (Sula dactylatra), brown booby (Sula leucogaster), red-footed booby (Sula sula), wedge-tailed shearwater (Puffinus pacificus), Christmas shearwater (Puffinus nativitatis), petrels (Pseudobulweria spp.,Pterodroma spp.), tropicbirds (Phaethon spp.), frigatebirds (Fregata spp.), and noddies (Anous spp.).
The world’s largest Laysan albatross colony is located on Hawaii’s Midway Atoll where lead paint is reported to be flaking off of deteriorating buildings. Paint chips are consumed by albatross chicks as they wait for their parents to return with food and the American Bird Conservancy has stated that these chicks have shockingly high lead concentrations. The organization estimates that 10,000 chicks die each year as a result. The USFWS has stated that they plan to clean up as many buildings as possible over the next two to four years and will also excavate chip-contaminated soil from around the buildings and six inches down. The soil will be replaced with clean beach sand.
Following consultations under section 7 of the ESA, NMFS has determined that the bottomfish, crustaceans, coral reef, and precious coral fisheries in the Exclusive Economic Zone around the Hawaii Archipelago will not adversely affect any ESA-listed species or critical habitat.
NMFS has also concluded that the commercial fisheries in the Hawaii Archipelago will not affect marine mammals in any manner not considered or authorized under the Marine Mammal Protection Act.