Status of sea turtle stocks in the Pacific

Six species of sea turtles occur in the Pacific Ocean (green turtles, loggerheads, leatherbacks, hawksbills, olive ridleys and flatbacks). All species, except flatbacks, have transboundary distributions. The status of most sea turtle stocks in the Pacific Ocean is poorly understood. Some stocks are increasing, such as in eastern Australia and Hawaii. However, there is evidence that many stocks have been reduced significantly, which is mainly a result of overharvesting of eggs, subsistence or commercial harvest of large turtles and nesting habitat destruction. Incidental capture in coastal and pelagic fisheries can also be an important source of mortality for some stocks. Abundance trends for the six Pacific species of sea turtles are reviewed, using the best available quantitative information. INTRODUCTION The status of the sea turtle stocks in the Pacific Ocean basin is poorly understood (Spotila et al., 1996; Meylan and Donnelly, 1999; Chaloupka and Limpus, 2001; Seminoff, 2002). Many stocks have been reduced significantly, which is mainly a result of overharvesting of eggs (Meylan and Donnelly, 1999; Chaloupka, 2001; Seminoff, 2002), subsistence or commercial harvest of large turtles (Horikoshi et al., 1994; Meylan and Donnelly, 1999; Trinidad and Wilson, 2000; Gardner and Nichols, 2001; Limpus et al., 2004) and nesting habitat destruction (Sharma, 2000; Matsuzawa et al., 2002). Other sources of mortality can have local importance, such as fibropapilloma disease (Chaloupka and Balazs, n.d.) or tiger shark attack (Heithaus, Frid and Dill, 2002; Balazs and Chaloupka, unpubl. strandings data for Hawaii). Incidental capture in coastal and pelagic fisheries can also be an important source of mortality for some stocks (Chan, Liew and Mazlan, 1988; Cheng and Chen, 1997; Chaloupka, 2003b).