Preliminary study on the catch distribution of bigeye tuna (Thunnus obesus) longline and fishing grounds environment in the Pacific Ocean

The bigeye tuna longline fishery is one of the important fisheries in the Pacific Ocean. Based on the bigeye tuna catch data collected, sea surface temperature derived from satellite 3-level production and literatures,the bigeye tuna longline fisheries were analyzed quantitatively or qualitatively by using GIS technology. The results showed that the distribution of bigeye tuna longline fishing grounds is mainly in the tropical areas between 20°N and 20°S. The analysis of the relationship between catch statistics by month and average SST indicated that the favorite monthly SST of the bigeye tuna longline fishing grounds was 28～29℃. The frequency distribution style of the fishing grounds is the skew one. Finally, the relationship between the distribution and formation mechanism of the fishing grounds and the environment factors such as SST, dissolved oxygen (DO), sea current were herein discussed.