Spatial distribution of Larimichthys polyactis in Wen-Tai fishing ground based on habitat suitability index

Abstract:

According to the investigated data of fishery resources and habitats of comprehensive survey on Wen-Tai fishing ground in four seasons in 2015-2016, using normal distribution function respectively the sea bottom temperature (SBT), sea bottom salinity (SBS), water depth, and by the relative density of resources suitability index (SI) were built, and by used the least squares parameter model, based on different weight arithmetic average method (AWM), the habitat suitability index(HSI) model was also built. According to the data of resource density, bottom temperature, bottom salinity and depth, the boosted regression tree (BRT) was also built used to evaluate the weight of each environmental variable in the HSI model, and the model accuracy was tested by cross validations. It was found that there was a significant normal relationship between environmental factors and SI. Larimichthys polyactis optimal habitat has an obvious seasonal change of habitats.The whole-year high value appeared in spring and summer, followed by autumn and winter, the spring high value area is located in east of 122°30'E, north of 28°30'N summer strip of south high value area, autumn high value area is located at 122°00'E, 28°00'N, winter high value area north is located 123°00'E, 29°00'N. The results showed that the model can positively reflect the distribution and variation of the habitat of the Larimichthys polyactis in the warm stage after considering the weight in the HSI model.