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Species Invasions Threaten the Antiquity of China’s Freshwater Fish Fauna

Increasing establishment and spread of common nonnative species is leading to a dramatic reconfiguration of modern biodiversity. The widespread invasion of ubiquitous nonnative species could result in significant impoverishment of faunas and irretrievable disorder of ecosystem function by decreasing β diversity among communities. However, the majority of research efforts on elucidating patterns of biotic homogenization mainly focused on the developed countries from North America and Europe, with hardly any systematic investigations in developing countries like China. 

By collaborating with Professor Julian Olden from University of Washington in Seattle, Research Group of Biological Invasion and Adaptive Evolution (BIAE; PI: Yifeng Chen) at Institute of Hydrobiology, Chinese Academy of Sciences (IHB) answered how China’s freshwater fish fauna changes with widespread species invasions.  

Results showed that species introductions have homogenized freshwater fish faunas across China by increasing overall compositional similarity of watersheds from a historical 14.9% to 21.9% in the present-day. Western basins exhibited the significantly higher magnitude than eastern basins. Translocated nonnative species associated with aquaculture practices contributed the most (7.3%) to faunal homogenization when compared to alien species (0.4%), indicating the translocation of domestic species was the main driver of homogenization of China’s freshwater fish.  

This research systematically documented that China’s freshwater fish have experienced substantial loss in β diversity over time and can provide the theory foundation for guiding China’s biodiversity protection strategies at the country scale.  This research has been recently published in Diversity and Distributions.   

Additionally, BIAE also published research in Reviews in Fish Biology and Fisheries which elucidated the introduction vector, establishment and damage of nonnative freshwater fish in China. This work has attracted attention from scientists working on freshwater ecology and biological invasions. 

 

Figure. Change in β diversity between historical and present-day fish fauna caused by species invasions and extinctions. (a) Mean compositional changes for all 103 watersheds. (b) Mean compositional changes for all ecoregions. (c) The division of nine major basins in China. (d) Compositional changes for nine basins. (Figure by IHB)