Study On Fishing Ground Spatial Distribution And Habitat Suitability Index(HSI) Model Of Chilean Jack Mackerel(Trachurus Murphyi) In The Southeast Pacific Ocean

Chilean jack mackerel(Trachurs murphyi) is one of the most important economic species in the southeast Pacific Ocean, and also Rushed to catch by the Pelagic fishery countries.Due to the height migratory of Chilean jack mackerel, and widely distributed, fishery resources and the centre of fishing ground changes have Large interannual differences, the difficulty is higher to Grasp the variation of spatial and temporal. In recent years, with the increase in the cost of fishing, the way how to efficiently predict the central fishing ground of the C hilean jack mackerel urgently needs to be solved. This paper was to analyze the law of the spatial and temporal distribution of squid fishing ground grativity based on the statistical data of C hilean jack mackerel in the Southeast Pacific Ocean during 2004~2014. On the basis of analysis the relationship between of the C hilean jack mackerel fishing ground and SST, SSS and other parameters on the marine environment, by conducting different based on habitat suitability index model to study the Chilean jack mackerel fishery characteristics of the marine environment, and find the best weightings sequence. For verification and analysis the weightings of the HSI model to provide a scientific basis for the accurate prediction of the distribution of center fishery ground and resources development status.(1) The changes of Chilean jack mackerel center fishing ground. Center fishing ground began moving from south to north from March, and divided into two seas in August, one gradually shift to the northwest, another one gradually shifted to the northeast, and shift to the northernmost in November. The fishing ground are mainly in the range 80 ~ 90 ° W, 40 ~ 46 ° S from March to May during 2004-2014, June fisheries mainly concentrated in t he range of 78 ~ 88 ° W, 39 ~ 42 ° S,and distribution range is 78 ~ 88 ° W, 36 ~ 40 ° S in July, in August fishing grounds mainly in the two seas 84 ~ 94 ° W, 34 ~ 48 ° S and 76 ~ 80 ° W, 29 ~ 31 ° S, in September is 86~95°W,30~46°S and 74~86°W 、 26~29°S,in October is 84~96°W,30~36°S and 75~78°W,26~30°S,in November is 92~96°W,34~36°S and 74~78°W,26~30°S. The results of the clustering show that the center of fishing ground distribution has a great difference from March to November. March clustering into three categories, divided into four categories in April, May divided into two categories, divided into three categories in June, July divided into five categories, apart from September in three categories, and others are divided into two categories.(2) The relations between the distribution of C hilean jack mackerel fishing marine environmental factors. With the change of the month, the SST of C hilean jack mackerel fishing ground increased gradually, the trends of SSS is the same of SST. During March to June: SSS 33.9~34.0‰, while the range of SST have some changes, During March: SST 11 ~ 15 ℃, During April: SST 12 ~ 14 ℃, During May to June: SST 10 ~ 14 ℃. During July: SST 12~14℃; SSS 34.0~34.1‰. During August: SST 13~15℃; SSS 34.0~34.1‰. During September: SST 11~14℃; SSS 33.9~34.2‰. During October: SST 15~16℃; SSS 34.4~34.6‰. During November: SST 14~17℃; SSS 34.1~34.3‰.(3) the weightings of marine environment’s influence on HIS model.By calculating the percentage value of CPUE and NET in the ten different weightings sequences, which based on the CPUE and NET. The results show that in the five different weightings of HSI model which based on N ET, in March based on SST and SSS weightings value(0.2, 0.8) is the best; April weightings(0.6, 0.4) is most representative, May is weightings of(0.8, 0.2), from June to September are the best fitted model is(0.4, 0.6), October and November is weightings of(0.2, 0.8) works best. In the different weightings of HSI model which based on CPUE, March and April are the best weightings of(0.2, 0.8),(0.6, 0.4); May is(0.4, 0.6), from June to November, in addition to September the best model to fit the weights is(0.8, 0.2), the other is(0.2, 0.8) of HSI model fit best results.(4)Verification and analysis the HIS model of the C hilean jack mackerel.According to the marine environment date and production data in2014 to validate and analysis of habitat suitability index model.It is concluded that the most appropriate SST and SSS under the weightings of the value of the HIS is in conformity with the actual fishing production in 2014.Research shows that the Southeast Pacific Chilean jack mackerel fishing ground SST and SSS spatial distribution and trends in 2014 is consistent with previous years. Fitting results are good months is June and July based on the NET, the proportion of NET is not high in August, but reference the CPUE has a better fitting effect. Fitting results are good months is June,July and August based on the CPUE, Comprehensive analysis shows that the HSI model can predict appropriate Chilean jack mackerel fishing ground.