Application of the European Non-native Species in Aquaculture Risk Analysis Scheme to evaluate Micropterus nigricans in China

Largemouth bass Micropterus nigricans has caused a wide range of invasive impacts and is listed among the top 100 of the World’s Worst Invasive Alien Species by IUCN. Yet it has been widely introduced around the world due to sport fishing needs and its importance for aquaculture. It also has been promoted most vigorously in the past five years in China, where the production of M. nigricans exceeded 90% of the total production of perches in 2019. In this study, the invasion risk of M. nigricans was assessed using AS-ISK andfound to he high in the middle and lower reaches of the Changjiang River. The European Non-native Species in Aquaculture Risk Analysis Scheme (ENSARS) was therefore used to evaluate the full invasive risk of M. nigricans in the same area. The results suggest that M. nigricans carries an overall medium risk of invasion in China, with every module suggesting a medium risk. Confidence ranks for the overall scores fell into the range of 2.0–2.5, which suggests a high confidence level. This study is meant to be a trial for further use of the ENSARS scheme in China, especially for potential non-native aquacultural species.