中东太平洋公海金枪鱼延绳钓误捕海龟的观察和分析

根据2006年2－11月科学观察员对热带东太平洋公海海域(05°N～10°S,134° W~173°W)金枪鱼延绳钓渔业的调查，期间共投钩223次(天)，误捕到绿海龟、蠵龟、丽龟、玳瑁和棱皮龟5种共22尾，死亡海龟13尾。从海龟误捕率看，平均每次尾数为0.098 65。平均每千钩尾数0.037 40。从海龟的钩获部位看，喙(嘴)上钩占41.0%，躯干部位上钩占13.6%，喉部上钩占13.6%，前肢上钩占18.2%，主绳缠绕被捕获占13.6%。海龟的误捕区域位于04°S以北海域，几乎可全年捕获。此外分析了不同钩位误捕海龟的数量，探讨了影响误捕率和死亡率的因素，提出保护对策。

Observation and Analysis of Sea Turtles Mortality Longline Fishing in High Seas of Central and Eastern Pacific Ocean

Based on the data by scientific observer survey in the tropical Central and Eastern Pacific Ocean (05°N -10°S,134° W -173°W) by the tuna longline fishery targeting bigeye tuna during Feb.-Nov. , 2006, with the total 223 sets, 22 sea turtle bycatch were observed and analysed. The incidental sea turtles were classified as 5 species, namely green sea turtles (Chelonia mydas),loggerhead (Caretta caretta),Oliver ridley turtle (Lepidochelys olivacea), hawksbill turtle ( Eretmochelys imbricata) and leatherback turtle (Dermochelys coriacea) with total 22 individuals. There were 13 sea turtles mortality after capture. The incidental catch rate is 0. 09865 per set and 0. 374 0 per thousand hooks. The interaction between fishing gear and sea turtles showed that sea turtle body were hooked with mouth accounting for 41. 0% , external parts 13.6% , swallowed 13.6% .foreleg 18.2% and mainline entangement 13.6%. Most sea turtle bycatch occurred north of 04°S and almost all the year round. Analysis was also made to identify the specific hook number for interaction with sea turtles. Discussion was made on factors for affecting catch rate and mortality. Measures were suggested on conservation and by-catch mitigation for sea turtles.