Assessing the effects of contaminated sediment on fish of the St. Lawrence River (Cornwall) AOC

Session: 07. - Effects of Environmental Contamination on Fish Communities

Dominique Lapointe, St. Lawrence River Institute of Environmental Sciences, [email protected]
Matthew Windle, St. Lawrence River Inst., [email protected]
Patrice Couture, INRS - Eau Terre Environnement, [email protected]
Jeff Ridal, St. Lawrence River Institute, of Environmental Sciences, [email protected]

Abstract

Despite environmental regulations, improved industrial practices and long-term declines in mercury (Hg) levels, zones of contaminated sediments displaying concentrations of mercury that exceed Ontario’s sediment quality guidelines remain within the St. Lawrence River (Cornwall) Area of Concern (AOC). These zones also contain elevated levels of other trace elements. “Restrictions on Fish and Wildlife Consumption” are still in effect within the AOC, but little is known about the effects of these contaminants on fish condition. This study aimed to assess (1) the extent to which contaminants present in the sediment in nearshore areas of the AOC accumulate in sentinel fish species, and (2) whether contaminants affect the condition of fish inhabiting these zones. Fish were collected at impacted and non-impacted sites. Various indicators were examined, compared among sites and correlated to determine the effects of environmental contamination on fish within the AOC. Spatial trends in Hg concentrations in fish collected from the contaminated zones revealed variable levels of bioaccumulation depending on site and species. Overall, Hg concentrations remained greater in fish exposed to contaminated sediment than in fish from non-impacted locations, suggesting continued availability of legacy Hg in sediments and/or continued inputs of bioavailable Hg to the ecosystem from other sources.

1. Keyword
bioaccumulation

2. Keyword
fish

3. Keyword
sediments