Annual comparison of Chile jack mackerel (Trachurus murphyi) spatiotemporal distribution in the southeast Pacific

Abstract:

Based on the fishing activity data of China trawlers in the southeast Pacific from 2003 to 2012, and by using the methods of GIS geostatistics and spatial analysis, this paper analyzed the spatiotemporal distribution and its interannual difference of Chile jack mackerel (Trachurus murphyi) stock density. The results showed that variations in the spatial distribution of Chile jack mackerel in different years were obvious. In 2003 and 2004, the high value area of stock density was distributed in the northeast waters of 78°-85°W, decreased from the northeast waters to the southwest waters; In 2005, 2006 and 2007, it was similar to that in the previous two years, but the variation gradient was smaller than before; In 2008 and 2009, the high value area of stock density scattered, the distribution trend of stock density was not obvious; In 2010, the stock density had a trend of decreasing from the western waters to the eastern waters, the most of high value area distributed in the west waters of 93°W; In 2011, the high value area of stock density distribution was in the northwest waters; In 2012, the high value area of stock density distributed in the western waters of 28°-38°S, decreasing from the western waters to the eastern waters. The results of hot spot analysis and geostatistics analysis are basically the same, and the results of the two analysis methods can support each other. The high value points of Chile jack mackerel stock density are distributed in the north waters of 45°S.