Fishing in Lake Champlain? Researchers Encourage Anglers to Learn Which Fish Are Safe to Eat

By Anna Marchessault
October 10, 2023

Lake Champlain and its tributaries have an avid fishing community that spends $205 million per year on fishing. Many anglers fish for sport, but some anglers that fish for food from the Lake Champlain region are underrepresented. This group has not been rigorously studied and may or may not know the potential health risks that can come from consuming certain fish. Roxanne Karimi, a Research Scientist at Stony Brook University, just finished up a two-part project studying both mercury, a contaminant in fish that impacts human health, and angler behavior. During her field study, she studied mercury dynamics in the winter in Lake Champlain, a topic that has been widely overlooked by scientists, yet is critical to understand as the climate changes. She also created and disseminated a survey to local anglers to analyze local fishing habits.

To understand mercury year-round bioaccumulation, trophic transfer, and risks to wildlife and human health, Karimi and her team sampled concentrations of mercury in lake sediments, and the water column. The team set out to understand whether ice cover reduces or enhances mercury bioavailability, or supply to the food chain. This information will help to better predict and prepare for future lake mercury levels with changing winter conditions that include much less ice cover. This can then help the researchers understand if mercury levels in fish will likely increase or decrease with these changing conditions.

Karimi and her team also surveyed Lake Champlain anglers. They wanted to learn, out of the people going fishing, how many fished primarily for food and how many fished primarily for sport to understand the human health risks associated with fish contaminants. The researchers found about 85% of anglers in the survey fished for sport while only 14% fished for food. However, the number of people who primarily catch fish for food may be underestimated. Studies from other regions show that people who primarily catch fish for food include recent immigrants or indigenous groups who are often underrepresented in surveys.

Most anglers (80%) said they are aware of consumption advisories. The respondents who fish for food included more individuals with low incomes (<$35,000/year) compared to those who fish for fun. Past outreach efforts have assumed that the risk of mercury exposure from eating fish grows with income so these anglers may have been overlooked in education and communications surrounding fish contaminants.

The respondents who fish for food reported fishing more consistently throughout the year than those who do for sport, specifically through the winter. This did not have much impact on the regularity of fish consumption. When asked how often they consume fish—either from the lake or from the store—both subsistence anglers and sport anglers tend to eat fish between 2 to 4 times a month. The researchers also collected useful data about how anglers prefer to learn about fishing advisories and where to post information for anglers to see.

Karimi and her team are using their findings to inform larger-scale studies that are needed to understand the effects of climate change on fish safety, and to effectively engage with anglers about the current and future risks of mercury and other contaminants in the fish of Lake Champlain.

“In the meantime, the most important thing anglers can do is to keep learning about the types and amounts of fish that are safest for them and their family to eat,” Karimi advises. To get accurate information on fish contaminants and consumption guidelines, read the Vermont Department of Environmental Conservation’s Fish Advisory Card and Lake Champlain Basin Program’s page on fish advisories.