关键词: 棕斑兔头鲀, 广义加性模型(GAM), 资源密度, 北部湾, 环境因子

Abstract: To elucidate the influence of marine environmental factors on the distribution of Lagocephalus spadiceus, we analyzed fisheries and environmental survey data from the Beibu Gulf in April (spring) and August (autumn), 2022. We used the generalized additive model (GAM) to examine the relationship between the distribution of L. spadiceus and marine environmental factors, both before and after the implementation of a fishing moratorium. We showed that the density of L. spadiceus in the Beibu Gulf exhibited significant spatio-temporal variation, which concentrated in the central and northern parts of the gulf during spring and autumn, respectively. Such variation in resource density may be attributed to factors such as chlorophyll a content, salinity, pH, and latitude. The GAM accounted for 91.3% of the cumulative variance in resource density. The resource density of L. spadiceus increased with the increases of chlorophyll content, while it began to decrease after chlorophyll reaching 5 μg·L^-1. Both salinity and pH demonstrated a nonlinear relationship with resource density, characterized by multiple peaks, while latitude was positively correlated with resource density. This research provides valuable scientific evidence for the conservation of L. spadiceus resources.

Key words: Lagocephalus spadiceus, generalized additive model (GAM), resource density, Beibu Gulf, environmental factor