February 15, 2019 — Climate change and the loss of wetlands may contribute to increased levels of mercury concentrations in coastal fish, according to a Dartmouth College study.
The finding implies that forces directly associated with global change — including increased precipitation and land use modifications — will raise levels of the toxic metal that enter the marine food chain.
Estuaries, including coastal wetlands, provide much of the seafood that is harvested for human consumption and also serve as important feeding grounds for larger marine fish.
The study, published in late December in the journal Environmental Pollution, adds to the mounting body of research that indicates a complex relationship between the environment and mercury pollution.
“Estuaries provide habitat for the fish that feed our families,” said Celia Chen, director of the Dartmouth Toxic Metals Superfund Research Program. “It’s important to understand how mercury acts within our environment, particularly under increasing climate and land use pressures.”
The Dartmouth study concludes that higher levels of mercury, and its toxic form methylmercury, are associated with higher organic carbon in coastal waters. The study also finds that this results in higher levels of mercury occurring in fish that frequent these waters.