So What Is Really Bugging Them: A Relative Risk Analysis of Connectivity and Pathogen Dispersal

Connectivity is one of the key processes of aquatic systems as highlighted by the National Fish Habitat Partnership Science and Data Framework Document (available at www.fishhabitat.org).  Connectivity is known to be critical for system energy flow, to complete life history stages for aquatic organisms, and to maximize aquatic production.  One of the key vectors for pathogen dispersal is fish movement which is enhanced by increased connectivity and could move epizootic causing pathogens into naïve populations.  So how does a resource manager resolve this conflict when presented with an opportunity to rehabilitate connectivity?  The key is to understand the relative contribution or risk of each factor and this paper will focus on how to accomplish this task.  A risk/profit analysis process will be performed and compared between both factors using a series of case histories.  For connectivity, case histories will be reviewed, summarized and scored for species, number, life stage or fisheries management goals, and system energy flow variables.  For pathogens, the Great Lakes Fishery Commission – Great Lakes Fish Health Committee Risk Assessment process will be employed which examines and scores the risk of the likely pathogens, intensities in the source and receiving populations, and the fish health affects of the pathogen.   Comparative risk/profit analysis will be done for each case study to inform the decision process on how connectivity should implemented based on these two factors and this analysis also provides key insights on data gaps and uncertainties in the decision process.