Invasive non-native species are one of the main threats to biodiversity. Recently, more than 30 non-native species were reported to have established in the four major rivers of South Korea, and introduction of non-native species is gradually accelerating. However, ecological information necessary for prevention and management of non-native species introductions and consequent spread is lacking in South Korea, and especially so for freshwater non-native species. In this study, we assessed eight non-native freshwater fishes established in the Geum River watershed [the Risk Assessment (RA) area] using the Aquatic Species Invasiveness Screening Kit (AS-ISK). Receiver operating curve analysis identified threshold values of 24.75 for the BRA (Basic Risk Assessment) and 35.75 for the BRA+CCA (BRA + Climate Change Assessment). Four species, namely Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides and Oreochromis niloticus were ranked as ‘high risk’; whereas, the lowest scoring non-native species was Coreoperca kawamebari, which is not likely to be invasive in the RA area because it has not established self-reproducing populations and its distribution is currently narrowing across the country. The results of this study indicate that application of AS-ISK allows the assessment of potentially invasive non-native species and provides a framework of action for the development of management guidelines for non-native species and the conservation of native species (cf. ecological traits such as species competition, habitat preference, food resources, and reproduction). As a case study for the Geum River watershed in South Korea, it is recommended that additional screening studies should be carried out for the non-native species in the four major rivers of South Korea.

• Jeong-Eun Kim(Department of Biological Science, Sangji University) | 김정은
• Lorenzo Vilizzi(Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Lodz)
• Gordon H. Copp(Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Lodz, Centre for Environment, Fisheries and Aquaculture Science, Department of Life and Environmental Sciences, Bournemouth University)