Temporal trends in near-shore sediment contaminant concentrations in the St. Clair River and potential long-term implications for fish tissue concentrations

The Niagara River mussel biomonitoring program (Elliptio complanata): 1983–2009

“…Since then, there have been several changes in analytical methods to incorporate new technology which can be found in Richman andSomers (2005, 2010), Richman and Milani (2010) and OMOE (2008a,b). Long term data comparability was considered when methods were changed and, results over the duration of the program are comparable.…”

“…Mussel samples were analyzed for total-PCB using the OMOE method E3136 and sediment samples were analyzed using OMOE method 3270 (Richman and Somers, 2010;Richman and Milani, 2010). Briefly, tissue samples (5 g) were digested with hydrochloric acid and extracted with hexane/dichloromethane.…”

A Study Design for the Assessment of Fish Tumour Prevalence in the Lower St. Clair River

“…Clair River (ENVIRON International Corporation, 2009). It is also possible that new contaminants being added to the St. Clair River are adding to contaminants remaining from previous discharges (Richman and Milani, 2010).…”

“…It is, perhaps, for this reason that historical data show contaminant concentrations in fish tissue to have declined since 1978, but remaining stable since the mid-1980s, consistent with the sediment contamination data described above. This information suggests that, despite remediation efforts, contaminated sediments continue to be bioavailable in the St. Clair River (Richman and Milani, 2010). Species-specific analysis of fish tissue contamination indicate the highest levels of total contaminants in the tissue of northern pike and redhorse sucker, respectively, and intermediate levels of risk for carp, freshwater drum, white sucker and yellow perch, respectively (ENVIRON International Corporation, 2009).…”

“…Despite these efforts, surface sediment contaminant data collected by the Ontario Ministry of Environment (MOE) and Environment Canada (EC) in the AOIfrom 1990 to 2008 indicate that levels of mercury and several other chlorinated organic compounds vastly exceed Provincial Sediment Quality Guidelines (SQG) and reference conditions(Richman and Milani, 2010), along with subsurface sediment showing concentrations of mercury up to five times the surface concentrations and spanning a much greater distribution area(ENVIRON International Corporation, 2009).…”