Influence of sea surface temperature and La Nia event on temporal and spatial fluctuation of chub mackerel(Scomber japonicus)stock in the East China Sea

Based on the catch and fishing effort data from small scale traditional light seining fisheries of Zhejiang Province and abundance data estimated by Fisheries Agency of Japan,the influence of the sea surface temperature(SST) from East China Sea and sea surface temperature anomaly(SSTA) from Nio 3.4 area on the stock size of chub mackerel in East China Sea was analyzed.The results showed that there were significant positive relation(P0.05) between SST and CPUE derived from small scale traditional light seining fisheries of Zhejiang Province and significant negative relation(P0.05) between SST and abundance from Japan.The averaged SSTA of Nio 3.4 from January to March can be considered as an index which roughly reflected abundance levels.When the averaged SSTA was negative,there was a great chance in lean year for chub mackerel stock,and vice versa.The opposite relationships between SST and abundance from different areas may be attributed to the influence of SST on migration of chub mackerel.La Nia event would have a negative impact on the resource in the whole East China Sea,but the reason needs to be investigated in the future.The results indicated that the temporal and spatial dynamics of the stock should be included in the stock assessment for chub mackerel.