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2016/09/20 14:00 Prof. Ming-An Lee（Department of Environmental Biology and Fisheries Science, NTOU）
Seminar
Poster： ╱ Post date：2016-09-19NCU IHOS Seminar Announcement
Speaker：Prof. Ming-An Lee
Place：S-325, Science Building 1
Abstract：
Title：Cyclic and marine environmental variations associated with fishing conditions of yellowfin tuna in the western Indian Ocean
Speaker：Prof. Ming-An Lee
Department of Environmental Biology and Fisheries Science, NTOU
Time：09/20（Tue.）14：00
Place：S-325, Science Building 1
Abstract：
Variations in the abundance and distribution of pelagic tuna populations have been associated with large-scale climate indices such as the Southern Oscillation Index in the Pacific Ocean and the North Atlantic Oscillation in the Atlantic Ocean. Similar to the Pacific and Atlantic, variability in the distribution and catch rates of tuna species have also been observed in association with the Indian Ocean Dipole (IOD), a basin-scale pattern of sea surface and subsurface temperatures that affect climate in the Indian Ocean. The environmental processes associated with the IOD that drive variability in tuna populations, however, are largely unexplored. To better understand these processes, we investigated longline catch rates of yellowfin tuna and their distributions in the western Indian Ocean in relation to IOD events, sea surface water temperatures (SST) and estimates of net primary productivity (NPP). Catch per unit effort (CPUE) was observed to be negatively correlated to the IOD with a periodicity centered around 4 years. During positive IOD events, SSTs were relatively higher, NPP was lower, CPUE decreased and catch distributions were restricted to the northern and western margins of the western Indian Ocean. During negative IOD events, lower SSTs and higher NPP were associated with increasing CPUE, particularly in the Arabian Sea and seas surrounding Madagascar, and catches expanded into central regions of the western Indian Ocean. These findings provide preliminary insights into some of the key environmental features driving the distribution of yellowfin tuna in the western Indian Ocean and associated variability in fisheries catches.
Last modification time：2016-10-05 AM 11:49
