Add another item to the ever-growing list of the dangerous impacts of global climate change: Warming oceans are leading to an increase in the harmful neurotoxicant methylmercury in popular seafood, including cod, Atlantic bluefin tuna and swordfish, according to research led by the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Harvard T. H. Chan School of Public Health (HSPH).
Researchers developed a first-of-its-kind, comprehensive model that simulates how environmental factors, including increasing sea temperatures and overfishing, impact levels of methylmercury in fish. The researchers found that while the regulation of mercury emissions have successfully reduced methylmercury levels in fish, spiking temperatures are driving those levels back up and will play a major role in the methylmercury levels of marine life in the future.
The research is published in Nature.
“This research is a major advance in understanding how and why ocean predators, such as tuna and swordfish, are accumulating mercury,” said Elsie Sunderland, the Gordon McKay Professor of Environmental Chemistry at SEAS and HSPH, and senior author of the paper.
Read more at Harvard John A. Paulson School of Engineering and Applied Sciences
Image: A 1-degree increase in seawater temperature and a 20-percent decrease in mercury emissions result in increases in methylmercury levels of 10 percent in cod and 20 percent levels in spiny dogfish. (Credit: Harvard SEAS)