by Sofia Adams
A recent NECIR investigation found that, while mercury emissions from major Massachusetts sources have declined by 90 percent over the past two decades, mercury levels in the state’s freshwater fish hold stubbornly high, with many species too contaminated for pregnant women and children to eat. View photos from the investigation below
Largemouth bass in Burlington’s Mill Pond have mercury levels so high that children and women of childbearing years should not eat any fish from there, while the general public should limit consumption to two meals per month. Mercury emissions from major Massachusetts sources have declined by 90 percent over the past 20 years, but mercury levels in many local freshwater fish remain too high for pregnant women and children to eat.
Two local anglers fish in Haverhill’s Lake Saltonstall, while two local boys, Matthew Venturi and Aiden Benet, look on. Children and pregnant women should not eat any largemouth bass from the lake, while members of the general public should eat no more than two meals of it a month.
Two local anglers fish for trout, which is stocked by the state in Lake Saltonstall in Haverhill. Trout is safe to eat because most are caught before they accumulate too much mercury in their muscles.
Researchers are examining reasons for stubbornly high fish mercury levels, such as in Haverhill’s Lake Saltonstall, including mercury drifting on air currents from overseas power plants and small-scale gold mining operations, climate change, and reductions in acid rain.
Joan Martinez, a local fisherman, watches his line at Jamaica Pond, waiting for a bite from a fish he hopes to add to his day’s catch of bass and perch that he is taking home for dinner. Jamaica Pond is under the Massachusetts general advisory on mercury levels which advises that women of childbearing years and children not eat any fish from freshwater bodies in the state.
After catching an 8-inch bass he planned to eat for dinner, Alex P. (who declined to give his last name) casts again in Boston’s Jamaica Pond. In recent years, Massachusetts has halved the number of lakes it samples because of budget cuts.
A local fisherman checks a fishing pole in Haverhill’s Lake Saltonstall. Scientists know that lowering mercury emissions is critical to reduce mercury levels in lakes and fish, but “there is so much else that goes on in between” mercury pollution in the air and mercury building up in fish, said Bruce Monson, a mercury expert with the state of Minnesota.
An international treaty to reduce global mercury emissions between 128 countries, including the U.S., was negotiated two years ago and could help lower mercury levels in fish, such as Mill Pond, in Burlington (pictured here). “We need that treaty to reduce emissions across the world,” said Michael Bender of the Zero Mercury Working Group, a coalition of 90 groups from 50 countries. “The good news is … we are going to see reduced mercury pollution.”