Trends of legacy and emerging-issue contaminants in Lake Simcoe fishes

Lake-wide distribution and depositional history of current- and past-use persistent organic pollutants in Lake Simcoe, Ontario, Canada

“…However, concern over exposure to bioaccumulative chemicals like PCBs remains, and restrictions on consumption of sportfish from the Great Lakes and inland lakes continue. In Lake Simcoe, there are some limits on the number and size of sportfish that may be consumed safely because of PCBs and mercury (Gewurtz et al, 2011;OMOE, 2009).…”

Introduction and summary of research on Lake Simcoe: Research, monitoring, and restoration of a large lake and its watershed

“…In addition, Lembcke et al (2011) examine the factors that control the export of past-use organic chemicals and the potential risk for Lake Simcoe and its fishes. Long-term trends in fish contaminant levels and a comparison to consumption restriction guidelines for popular sport fishes are given in Gewurtz et al (2011). Finally, Oni et al (2011) use a process-based modeling approach to identify factors that control dissolved organic carbon (DOC) transport and export to the lake, a necessary first step for predicting organic matter and metal dynamics in a changing landscape.…”

Use of semipermeable membrane devices to investigate the impacts of DDT (Dichlorodiphenyltrichloroethane) in the Holland Marsh environs of the Lake Simcoe watershed (Ontario, Canada)

“…These species spend a portion of their lifecycle in the waters around the Holland Marsh where the higher DDT concentrations were observed, as well as a portion in Lake Simcoe. Both these factors may be involved in the plateau of fish tissue concentrations observed by Gewurtz et al (2011) as opposed to a continuing decline. As none of the other Lake Simcoe tributaries that were sampled in 2004 detected any DDT concentrations, this suggests the Marsh may be acting as a source of legacy DDT contamination to the immediate environs and potentially Lake Simcoe as well.…”

“…Generally, DDT concentrations in fish tissues have decreased since the 1970s and since the 1990s have stabilized (Gewurtz et al, 2011). This plateau is likely the result of changes to food webs (e.g.…”

“…and Bythotrephes longimanus) and a decline in new DDT sources with current contamination sourced from atmospheric deposition and historic sources (e.g. release from contaminated sediments) (Gewurtz et al, 2011;Stow et al, 1995).…”