Effects of climate change in the seas of China: Predicted changes in the distribution of fish species and diversity

Long-term habitat shifts in marine fishes under climate change have been discussed over the last few decades. However, there is still a limited understanding of how fish distribution and biodiversity patterns will change in the offshore areas of China over time. In the present study, the potential distributions of 21 important marine fishes under current conditions and two climate change scenarios up to the 2050 s were projected using the maximum entropy (MaxEnt) model. The predicted habitat shifts were further used to observe how future environmental changes would affect communities. By the 2050 s, nine out of 21 fish species may have reduced habitats, which were considered as potential loser species in adapting to climate change, while the other 12 fish species were considered as winner species. The habitats of 20 species were predicted to move northward, with a mean habitat centroid shifting distance from 110 to 206.5 km. A novel discovery is that the Yangtze River Estuary is probably a geographical barrier for the northward migration of some species. An asymmetry in the habitat range shift was observed within the study region, wherein the leading edge moved 1 degrees faster than the trailing edge. The Beibu Gulf, Pearl River Estuary, Southwest Taiwan Strait, and Yangtze River Estuary were identified as fish refuges, indicating that large river estuaries and upwelling systems may have positive effects on reducing the vulnerability of biological communities to climate change. At the community level, species richness would be reduced at lower latitudes, while it would be increased at higher latitudes, and species turnover was the main component of temporal beta diversity. Our study provides an informative outlook on the impact of climate change on the distribution and biodiversity of marine fish species in China, supporting the adaptive conservation and management of fish habitats.

Automated summary

This study used the MaxEnt model to predict the potential distribution of 21 important marine fish species in offshore areas of China under current and future climate change scenarios. The results show that by 2050, nine fish species may lose habitats while 12 species may see their habitats shift northward. The Yangtze River Estuary was found to be a geographical barrier for the northward migration of some species. The Beibu Gulf, Pearl River Estuary, Southwest Taiwan Strait, and Yangtze River Estuary were identified as fish refuges, indicating their importance for the conservation and management of fish habitats.