| 英文摘要 |
Yellow-fin tuna is one of an important target fish of tuna long line fishery in the Indian Ocean, distributes widly in the north sea of 10 degrees south latitude mainly. This study collected the fisheries-based data of yellow-fin tuna and satellite-derived data, includes Sea surface temperature (SST), ocean color, Sea surface height and precipitation images in the Indian Ocean during the period of 1997-2004. GIS system is used to combine this data set in order to investigate the relationship between the distribution of yellow-fin tuna and the oceanic environmental factors. The catch data shows that sub-area 1 and 2 are the most important areas in the Indian Ocean, the catch percentage in these two areas are 27.2% and 54.9% respectively. In addition, the CPUE shows that the averaged CPUE of whole Indian Ocean is 2.39(inds/1000 hooks), and there is higher CPUE value in sub-area 1 of 6.99(inds/1000 hooks). In sub-area 1 the fishing season is from February to July, and in April the value is the highest. The CPUE in sub-area 2 is 2.82(inds/1000 hooks) and it shows a seasonality variation. After Principle Component Analysis (PCA) analyzing, the results shows high interrelated between CPUE, SST ,upwelling area, water temperature and salinity in the 100m depth and chlorophyll-a. Further, high catch and CPUE of yellow-fin tuna are appeared with the increasing of stability oceanic condition and SST. It also reveals a seasonal evolution of CPUE and oceanic condition in the Arabian Sea. |
