Impacts of climate changes on the habitat suitability of spawning ground for Konosirus punctatus in the central and southern Yellow Sea

Global warming will lead to great variations in ocean environmental variables, and the spawning grounds of fishes will be changed correspondingly. To comprehensively understand the changing patterns of spawning ground suitability of Konosirus punctatus under climate change and provide a scientific basis for the conservation of spawning grounds, fishery surveys were conducted in the spawning grounds in the central and southern Yellow Sea from May to July in 2014—2018 using ring net. Spawning grounds distribution of K. punctatus was analyzed by Random Forest model. Six environmental variables were selected in the model, including sea surface temperature, sea surface salinity, depth, offshore distance, sea surface velocity from FVCOM (Finite-Volume Community Ocean Model) and chlorophyll-a concentration from NOAA. In addition, the potential distribution of the spawning grounds of K. punctatus under future climate change scenarios was also predicted. Results showed that the main environmental factors affecting the spawning grounds were different by months, and the main factors were water depth, chlorophyll a and sea surface temperature from May to July, with relative contribution of 24.49%, 28.08% and 26.26%, respectively. The suitable spawning grounds of this species will migrate northward under climate changes. Moreover, the suitability of spawning grounds in the northern coastal waters of Haizhou Bay and the deep-water areas of the southern Haizhou Bay will increase significantly. Therefore, this trend should be fully considered in the future in terms of spawning ground protection and resource development and utilization.