Understanding and Predicting Impacts of Commercial Harvest on White Suckers in Maine

The State of Maine allows the harvest of white suckers, Catostomus commersoni, during their spawning. The fish provide lobster bait for coastal communities as an alternative to declining river herring harvest. The fishery is not regulated in areas that allow harvest and managers have expressed concerns that overfishing and/or incidental catch of other species may occur.  In order to assess the potential impacts of high rates of commercial exploitation, we constructed a heuristic model of a white sucker population. Demographic information from 976 fish collected from 6 lakes in Maine was used to input size-at-age, age-at-maturity, fecundity, growth, and mortality (calculated from 3 unfished lakes). We assessed sensitivity of age distributions to realistic levels of fishing mortality to project future population numbers. The results from this model will be used to consider the vulnerability of white suckers to harvesting pressure and aide in guiding management for harvesting.