Public Health Fish Consumption Advisory for Three Cape Cod National Seashore Ponds

Date: January 8, 2007
Contact: George E. Price, Jr., Superintendent, [phone] x202

Health officials in Wellfleet and Truro and Cape Cod National Seashore Superintendent George Price announce that they were notified this week by the Massachusetts Department of Public Health (MDPH) of a fish consumption advisory at Duck and Great Ponds in Wellfleet and Ryder Pond in Truro. The MDPH advisory is based on average fish-sampling results from the Department of Environmental Protection (DEP) that showed that mercury in fish from these three ponds was at or above the Food and Drug Administration’s Action Level for mercury of 1.0 mg/kg. Fish from the other two ponds sampled, Gull and Herring in Wellfleet, were below state advisory standards for mercury.

Mercury may accumulate in people who frequently eat fish contaminated with mercury thus leading to an increased risk of health effects. Because of health concerns associated with exposure to mercury, the MDPH recommends the general public not consume any fish from Duck and Great Ponds in Wellfleet and Ryder Pond in Truro. Fishing is still allowed in the ponds, but fish should be released and not consumed. Although mercury can accumulate in fish to levels that are sometimes thousands of times greater than the surrounding waters, this metal’s concentration in actual pond water is predictably very low. Therefore, swimming, boating and handling of fish are not likely to expose individuals to elevated levels of mercury. The Massachusetts Department of Public Health had previously (in 1994 and 2001) advised against freshwater fish consumption by pregnant women, nursing mothers and young children, because of observed mercury contamination in pond fish throughout the state.

In all, fish from five seashore ponds were sampled for mercury last spring by DEP, at the request of a team of US Geological Survey and National Park Service scientists who are studying the atmospheric deposition of mercury, and its accumulation in lakes, on both east and west US coasts.

Mercury is released into the atmosphere from the combustion of both fossil fuels and solid wastes from local and regional sources to pollute otherwise pristine lakes and ponds, like those here on the Cape. Once deposited in the ponds, mercury becomes concentrated in predatory fish at the top of the food chain. A higher accumulation of mercury in fish is expected in the more acidic ponds, like Duck, Great and Ryder. Sampling of the remaining 15 named kettle ponds within the seashore is planned for this spring.

Freshwater ponds and the aquatic animals that inhabit them are extremely sensitive to atmospheric deposition. Seashore scientists are concerned with and continue to monitor atmospheric pollution and its impacts to these critical habitats.

In addition, as reported by Northeast States Coordinated for Air Use Management (NESCAUM), recent efforts by the six northeastern states and the Eastern Canadian Provinces have resulted in a substantial decrease in mercury emissions into the atmosphere.

Additional information about the consumption advisory can be found through this link to the  Massachusetts Department of Public Health website.

-NPS-