Abstract
To investigate the spatiotemporal distribution characteristics of the dominant species, Portunus trituberculatus, and its relationship with environmental factors in the Yangtze River Estuary, this study utilized resource and environmental survey data collected from August 2022 (summer) to May 2024 (spring) in the estuarine waters. The relationship between the abundance of P. trituberculatus and environmental factors were analyzed using a Generalized Additive Model (GAM). Additionally, the spatiotemporal distribution of P. trituberculatus abundance was predicted. Results revealed that the best model deviance explained in spring, summer, and autumn was 88.6 %, 86.6 %, and 98.3 %, respectively, with average effect sizes of 0.63, 0.74, and 0.94 for cross-validated regression slopes. Key environmental factors affecting the abundance of P. trituberculatus in the Yangtze River Estuary vary by season. GAM results showed that the explanatory deviation of the spring model is 88.6 %. Lot, DO and pH have significant effects on the abundance of P. trituberculatus. The interpretation deviation of the summer model was 86.6 %, and DO had a significant effect on the abundance of P. trituberculatus. The interpretative deviation of the autumn model was 98.3 %. SBS, depth, and P. trituberculatus had significant effects on the abundance of P. trituberculatus. Moreover, P. trituberculatus abundance was associated with environmental factors through diverse functional forms, including linear, nonlinear, and multi-peak nonlinear relationships. In summary, this study provides scientific evidence for the conservation and sustainable management of P. trituberculatus resources in the Yangtze River Estuary, thereby contributing to the recovery and management of fishery resources in the region.
