Abstract: To understand the habitat distribution characteristics of Larimichthys polyactis in summer in Jiangsu coastal waters, we analyzed the relationship between resource density and habitat environment of L. polyactis by using a two-stage generalized additive model based on the survey data of fishery resources in August 2022, combined with the data of bottom water temperature, bottom salinity, depth, chlorophyll-a and prey species. The results showed that the average resource density of L. polyactis in summer was 15.03 kg·km^-2, which mainly distributed in the outer sea area of Lusi Fishing Ground and the middle sea area of Haizhou Bay Fishing Ground. The occurrence probability of L. polyactis was mainly affected by water depth and chlorophyll-a, with the contribution rate of water depth and chlorophyll-a being 40.8% and 10.2%, respectively. The resource density was mainly affected by water depth, chlorophyll-a, bottom salinity and the abundance of Chaemrichthys stigmatias. The bottom salinity was the variable with the largest deviation explanation (19.4%). Our results suggested that resource density of L. polyactis is closely related to its physiological habits, marine environment and the distribution of prey species.

Key words: Larimichthys polyactis, resource density, two-stage generalized additive model, habitat environment