Risk screening of the potential invasiveness of non-native aquatic species in Vietnam

Abstract

The impact of non-native species, together with their pervasiveness, necessitates a means of identifying which species are most likely to pose an elevated risk of becoming invasive. This is amongst the first applications of the Aquatic Species Invasiveness Screening Kit (AS-ISK) decision support tool in Southeast Asia, and specifically for Vietnam. In total, 30 extant and horizon non-native aquatic species were screened for their potential invasiveness in Vietnam. A threshold score of 6.75 was identified for distinguishing between species likely to pose a high and low-to-medium risk of becoming invasive in Vietnam for both the basic risk assessment (BRA) and the climate change assessment (BRA + CCA) components of the screening process. However, the absence of nationally-consistent predictions on climate change impacts in Vietnam restricted the applicability of the climate change assessment component. Based on the BRA threshold, of the 30 species screened, 25 were classified as high risk, four as medium risk, and one as low risk. For the BRA, the highest-scoring species were Hypostomus plecostomus, Pomacea canaliculata and Lithobates catesbeianus. This study reliably identified and discriminated between non-invasive and potentially invasive aquatic species in Vietnam, thereby providing appropriate AS-ISK score thresholds with which to guide policy and decision-making. This suggests that the AS-ISK could be successfully employed to screen non-native aquatic species in other parts of Southeast Asia.