Hawaii FEP - Western Pacific Fishery Council

(Landis 1965, in Eckert et al. 1986). The average dive lengths for adult females and males arereported to be 54.3 and 28.5 minutes, respectively (Plotkin 1994, in Lutcavage and Lutz 1997).Declines in olive ridley populations have been documented in Playa Nancite, Costa Rica;however, other nesting populations along the Pacific coast of Mexico and Costa Rica appear tobe stable or increasing, after an initial large decline due to harvesting of adults. Historically, anestimated 10-million olive ridleys inhabited the waters in the eastern Pacific off Mexico (Clifftonet al. 1982, in NMFS and USFWS 1998e). However, human-induced mortality led to declines inthis population. Beginning in the 1960s, and lasting over the next 15 years, several million adultolive ridleys were harvested by Mexico for commercial trade with Europe and Japan (NMFS andUSFWS 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 tosupply Europe with leather (Green and Ortiz-Crespo 1982). In the Indian Ocean, Gahirmathasupports perhaps the largest nesting population; however, this population continues to bethreatened by nearshore trawl fisheries. Direct harvest of adults and eggs, incidental capture incommercial fisheries, and loss of nesting habits are the main threats to the olive ridley’srecovery.3.3.4.2 Marine MammalsCetaceans listed as endangered under the ESA and that have been observed in the WesternPacific Region include the humpback whale (Megaptera novaeangliae), sperm whale (Physetermacrocephalus), blue whale (Balaenoptera musculus), fin whale (B. physalus), and sei whale (B.borealis). In addition, one endangered pinniped, the Hawaiian monk seal (Monachusschauinslandi), occurs in the region.Humpback WhalesHumpback whales (Megaptera novaeangliae) can attain lengths of 16 meters. Humpback whaleswinter in shallow nearshore waters of usually 100 fathoms or less. Mature females are believedto conceive on the breeding grounds one winter and give birth the following winter. Genetic andphoto identification studies indicate that within the U.S. EEZ in the North Pacific, there are atleast three relatively separate populations of humpback whales that migrate between theirrespective summer/fall feeding areas to winter/spring calving and mating areas (Hill andDeMaster 1999). The Central North Pacific stock of humpback whales winters in the waters ofthe Main Hawaiian Islands (Hill et al. 1997). At least six well-defined breeding stocks ofhumpback whales occur in the Southern Hemisphere.There is no precise estimate of the worldwide humpback whale population. The humpback whalepopulation in the North Pacific Ocean basin is estimated to contain 6,000–8,000 individuals(Calambokidis et al. 1997). The Central North Pacific stock appears to have increased inabundance between the early 1980s and early 1990s; however, the status of this stock relative toits optimum sustainable population size is unknown (Hill and DeMaster 1999).77