Lethal and sub-lethal responses of native freshwater mussels exposed to granular Bayluscide®, a sea lamprey larvicide: Data

The invasive sea lamprey poses a substantial threat to fish communities in the Great Lakes. Efforts to control sea lamprey populations typically involve treating tributary streams with lampricides on a recurring cycle. Elevated densities of sea lampreys in the aquatic corridor between Lakes Huron and Erie prompted managers to propose a treatment using Bayluscide®—a granular lampricide formulation that targets larval sea lamprey that reside in sediments. However, there was concern over the potential for adverse effects of this treatment on native freshwater mussels—imperiled animals that also reside in sediments. We estimated the risk of mortality and sub-lethal effects among eight species of adult and sub-adult mussels exposed to Bayluscide® for durations up to 8 hours to mimic field applications. At one of 12 time periods (0, 15, 30, 45, 60, 75, 90, 105, 120, 240, 360, or 480 min), one mussel from each aquarium was randomly removed, assessed for response variables (see below) and placed into a recovery raceway for 21 days. Response variables were: depth of burial into substrate, siphoning activity, dead or alive, and foot extension beyond shell margin.