Mercury burden in round goby and yellow perch in relation to riparian wetlands of the Upper St. Lawrence River

To examine if riparian wetlands are a source of mercury to fish, 174 yellow perch (Perca flavescens) and 145 round goby (Neogobius melanostomus) were collected in 2019 from eight wetland and seven non-wetland habitats throughout the Upper St. Lawrence River to examine mercury concentration differences between habitat types. Mercury levels were significantly (p < 0.01) higher in fish collected at wetlands than those collected from non-wetland habitats for both yellow perch and round goby. Perch had mercury concentrations of 74.5 ± 35.4 ng/g dry wt in wetlands compared to 59.9 ± 23.0 ng/g dry wt in non-wetlands. Goby had mercury concentrations of 55.4 ± 13.8 ng/g dry wt in wetlands and non-wetland concentrations of 41.0 ± 14.0 ng/g dry wt.