| 英文摘要 |
Catch per unit effort (CPUE) of Taiwanese distant-water longline fishery for bigeye tuna in the Western and Central Pacific Ocean (WCPO) was standardized using the generalized linear model (GLM) and the generalized additive model (GAM), respectively. Both results indicated that the standardized bigeye tuna CPUE increased in the past recent years after a long term decreasing trend. CPUE of Japanese distant-water longline fishery for bigeye tuna in the WCPO was standardized using the GLM, the result, however, did not show any increasing or decreasing trend. Since Japan harvested majority of the bigeye tuna in the WCPO, the age-structured production model (ASPM) was applied to assess the stock status for bigeye tuna in the WCPO based on the standardized Japanese and Taiwanese CPUE. Results indicated that the bigeye tuna in WCPO are likely to be overfishing and it is suggested that no further increase in fishing mortality in WCPO for bigeye tuna, and that the stock's condition and development in the fisheries should be monitored very carefully. Standardized CPUE of yellowfin and skipjack tuna from Taiwanese distant-water tuna longline and purse seine fisheries using GLM indicated a stable stock condition for both species, but there seems to have a slightly decreasing trend for yellowfin tuna, which need to be monitored. |