Non-native aquatic species in the Dongting Lake basin, China

Dongting Lake is the second largest freshwater lake in China, supports high biodiversity and many endemic or endangered species, such as finless porpoise (Neophocaena phocaenoides), Baer's pochard (Aythya baeri), and east Asian minnow (Ochetobius elongatus), and is thus a global biodiversity hotspot. It is located within an important aquaculture and agricultural region, and many non-native species were introduced into the lake for aquaculture and the ornamental trade. However, information about these non-native species is scarce. We sampled the lake and updated a list of the lake's non-native species, reviewed their status, and threat to biodiversity, as well as their contribution to aquaculture and fisheries. A total of 157 non-native species, including 14 fishes, 136 vascular plants, 1 amphibian, 2 crustacea, 2 mollusca, and 2 reptile species have been imported into Dongting Lake. The main pathways of introduction are through the ornamental trade (97 species, 62%), followed by unintentional introductions (23 species, 15%), aquaculture (13 species, 8%), herbal medicine uses (8 species, 5%), forage grasses (7 species, 4%), food (5 species, 3%), timber (2 species, 1%) and biocontrol and oil (1 species each, 1% respectively). The non-native species origins are North America (43 species, 27%), South America (42 species, 27%), Asia (29 species, 18%), Europe (28 species, 18%), Africa (13 species, 8%), and Oceania (2 species, 1%). Some non-native species, such as red swamp crayfish (Procambarus clarkii), channel catfish (Ictalurus punctatus), and parrot's feather (Myriophyllum aquaticum), are valuable for aquaculture and horticulture. However, other non-native species, such as Alternanthera philoxeroides, Pomacea canaliculate, and Trachemys scripta elegans, pose a potential threat to local biodiversity, human health, and sustainable development. Better management and control of non-native species in Dongting Lake are needed.