Supplementary files for an expert-based risk ranking framework for assessing potential pathogens in the live baitfish trade

Abstract

The purpose of this study was to develop a “hazard identification” and ranking tool to identify the pathogens that pose the highest risk to wild fish from the release of live baitfish by recreational anglers in freshwater systems. We developed a screening protocol and semi-quantitative stochastic risk ranking framework by combining published data with expert elicitation (n=25) and applied the framework to identify high-priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established, and host species) to characterize a pathogen’s ability to persist in the bait supply and cause impacts to wild fish species of concern. Of an initial list of 33, 15 potential pathogens met the criteria for inclusion and were evaluated using the semi-quantitative framework. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat to wild Minnesota fish, followed by the microsporidian Ovipleistophora ovariae, and viral hemorrhagic septicemia virus. Our findings contribute to the development of risk-based prevention and surveillance methods in support of front-line managers charged with maintaining both the aquatic sporting industry and sustainable, healthy natural resources in Minnesota. In addition, the ranking framework provides a standardized conceptual framework for prioritizing management as novel disease needs emerge.