Catch fluctuation on tuna purse seine fishery in the Western Pacific Ocean
Kim, H.S.; Takeuchi, S.; Nemoto, M.
Journal of the Tokyo University of Fisheries 84(1): 13-23
ISSN/ISBN: 0040-9014 Accession: 008270435
This study is an attempt to improve the detecting efficiency of the tuna purse seine fishing grounds in the Western Pacific Ocean. Catch and effort data which were provided by Japanese tuna purse seine fleet between 1983 and 1990 were analyzed with oceanographic data of 1980-1990 period from the Japan Meteorological Agency. The results are summarized as follows: The monthly variation was shown higher values on the 1st half of the year as contrasted with the lower values during the second half. In January, the central position of the fishing operations was located in the equatorial area, and it moved towards northwest as the months went by, then reaching up to 4 degree N in June. The center shifted southeastward returning back to the equator. The centroid of CPUE were indicated that the centroid of CPUE were positioned southern than 2 degree N between January and May, while these were shifted northern than 2 degree N from June to December. The annual moving average of CPUE seemed to be explained by a strong coefficient of correlation between CPUE and SST (Sea Surface Temperature) anomaly. This relationship was obtained when CPUE was cross correlated to SST anomaly on a time lag of 25 months in the Western Pacific Ocean. The central position of the fishing operations were located near 143 degree E between 1983 and 1985 and were moved eastward in the subsequent years. The centroid of CPUE were indicated similar shift. The above results can be used as valuable information to better explore the tuna purse seine fishing grounds in the Western Pacific Ocean.