Predicted increased distribution of non-native red drum in China’s coastal waters under climate change

Climate change and species invasions are among the most serious threats to global biodiversity, and climate change will further greatly alter the distribution of invasive species. The red drum Sciaenops ocellatus (Linnaeus, 1766) has established non-native populations in many parts of the world, leading to negative effects on local ecosystems. In this study, based on 455 global occurrence records (38 of which were in Chinese waters) and 5 biologically relevant variables (average ocean bottom temperature, ocean bottom average salinity, ocean bottom average flow rate, depth, and distance from shore), a weighted ensemble model was developed to predict the current potential distribution of red drum in Chinese waters and the future distribution under two climate change scenarios (RCP 26 and RCP 85). Based on the True Skill Statistics (TSS) and the Area Under Curve (AUC), the ensemble model showed more accurate predictive performance than any single model. Among the five environmental variables, the average temperature was the most important environmental variable influencing the distribution of red drum. Ensemble model prediction showed that the current suitable habitat of red drum was mainly concentrated on the coast of Chinese mainland, around Hainan Island, and the western coastal waters of Taiwan Province (17~41°N). Projections in the 2050s and 2100s suggested that red drum would expand northwards under both future climate scenarios (RCP 26 and RCP 85), especially in the western part of the Yellow Sea and along the Bohai Sea coast, which should be involved in the management strategies to maintain ecosystem structure and function.