Adaptation, Evaluation, and Calibration of FISK as a Risk Screening Tool for Non-Native Fish in Florida

The Fish Invasiveness Scoring Kit (FISK) is a semi-quantitative risk screening tool. Comprised of 49 questions on biogeography, biology, ecology, and “undesirable” traits, FISK produces a numerical score with which to categorize a species’ risk of becoming invasive. Using a revised version, FISK v2, enhanced for broader climate zone application, 98 non-native fish species observed in Peninsular Florida were assessed. FISK v2 accuracy in identifying species-specific risk was evaluated based on comparison to a priori risk categorizations from FishBase and a survey of fisheries professionals. FISK v2 scoring thresholds were also calibrated to reflect better the risks to Florida. Multiple independent assessments for each species were used to obtain a maximum, mean, minimum and range in scores. Preliminary analyses indicate FISK v2 is up to 80% accurate at identifying invasive fishes as high risk, while simultaneously maintaining 85% accuracy at identifying non-invasive fishes as low risk. Significant differences in scores for the same species screened by different assessors indicate a need to reduce uncertainty and user-subjectivity. When complete, FISK v2 will provide resource managers with a tool to assess quickly the potential risks of non-native fishes not yet introduced into Florida or other warm climate regions.