Seasonal Changes of Relationship Between Marine Environment and Squid Fishing Resources in North Pacific Ocean

The relationship of marine environment and squid fishing fluctuation in North Pacific Ocean was analyzed with the method of production gravity center and generalized additive model(GAM), through the surface temperature, sea chlorophyll and ocean current data got by satellite remote sensing inversion technology, and the statistic of boat fishing in the North Pacific from 2002 to 2012. The results showed that gravity center of fisheries was located in the eastern and central fishing grounds in May and June. The range was 168° ~171° E, 38° ~39° N.Gravity center of fisheries was located in western traditional fishing grounds from July to November with range of 150° ~160° E, 40° ~44° N.Gravity center of fisheries had obvious seasonal changes. GAM module analysis indicated that appropriate sea surface temperature scope of high squid fisheries was 14~19 ℃. The appropriate chlorophyll concentration scope of high squid fisheries was 0.22~0.55 mg·m-3. The distribution range was 154°~157°E in longitude, and 41°~44°N in latitude. There was a feeding migration to north and spawning migration to south every year, its relationship with environmental factors showed different characteristics, especially the best correlation of sea surface temperature. The gravity center of fisheries and sea surface temperature were positively correlated during the northward migration from May to September, while negatively correlated during the south migration from September to November. It showed obvious seasonal changes. Current also had an important impact on fisheries. Under the interaction of Kuroshio and Oyashio, high catch fishing grounds usually located in the forward of Kuroshio and nearby the northern side of Oyashio, with the shift of warm and cold current changing.