Spatial patterns of fish assemblages in the Pearl River, China: environmental correlates

Knowledge of spatial variations of fish assemblages in rivers in south China is limited, despite its ecological importance. Relationships between fish assemblages and selected habitat features were examined in the Pearl River, the largest subtropical river in southern China. Altogether, 94 fish species, representing 17 families and 5 orders were sampled. The dominant fish family was Cyprinidae, accounting for 49 taxa. Non-metric multidimensional scaling was applied to the collected data and it was found that the spatial variation of upstream fish assemblages was significantly different from downstream. Both water quality and habitat climate were significantly related to assemblages. Redundancy analysis revealed that the spatial patterns of fish assemblages were mostly explained by river width, temperature, river discharge, transparency and precipitation. It was concluded that the spatial patterns of fish assemblages in the Pearl River are closely associated with local abiotic features. Understanding the mechanisms such as those outlined in this research paper is the basis of conservation of fish community diversity, which is a critical resource to a successful sustainable wild fishery in the Pearl River.