The 2012 Great Lakes Water Quality Agreement states that “the Waters of the Great Lakes should allow for human consumption of fish and wildlife unrestricted by concerns due to harmful pollutants.”
Assessment highlights
The Fish Consumption indicator is based on the analysis of the fish filet, the commonly consumed portion of fish, to determine the risks of chemicals to human health. Over the last 40-50 years, many contaminants in fish filets have declined dramatically in the Great Lakes although the current rate of decline has slowed. The status of contaminants in the filets is based on the analysis of five commonly eaten fish species and is assessed as Fair and the trend is Improving.
Fish consumption advisories for Great Lakes fish primarily result from elevated PCBs and mercury concentrations, with PCBs driving the majority of advisories in both the U.S. and Canada. PCB levels in fish filets have decreased by 90% for some fish species in some lakes since the 1970s, but concentrations remain above unrestricted consumption benchmarks. Mercury levels in fish filets have generally declined by half over the last four decades. Based on PCB and mercury concentrations conditions are considered Fair in all lakes except in Lake Huron where conditions are Good. These fish consumption advisories have a greater impact on communities that heavily rely on fish for food and cultural, spiritual or economic purposes.
Over the past 10 years, PCB concentrations in fish filets have declined in most of the lakes while remaining stable in Lake Superior. During this same period, mercury levels have remained stable or decreased slightly. On this basis, the trend is assessed as Improving.
Other contaminants, such as per- and polyfluoroalkyl substances (PFAS), which have multiple uses including stain and water repellents, are now being more extensively monitored and have recently prompted issuance of fish consumption advisories for some areas of the Great Lakes.
PCBs in fish fillets have declined substantially but have generally stabilized in the 2000s
Sub-indicator supporting the Fish Consumption assessment
Sub-Indicator | Lake Superior | Lake Michigan | Lake Huron | Lake Erie | Lake Ontario |
Fair and Unchanging | Fair and Improving | Good and Unchanging to Improving | Fair and Improving | Fair and Improving |
Status
