Stranded dolphin-like mammals found suffering record levels of mercury poisoning
Scientists have found that dolphins in British waters have record levels of mercury in their livers.
New research has found that mercury levels in British waters have increased over time, with animals with higher levels more likely to die from infectious diseases.
Scientists who examined liver samples of 738 harbor dolphins stranded on the UK coastline between 1990 and 2021 found that the concentration of mercury in dolphin livers increased by 1 percent every year.
By 2021, the average mercury concentration was nearly double what it was in the early 1990s.
Along with the increase in mercury concentration in porpoise livers, scientists also saw an increase in the proportion of porpoises dying from infectious diseases and a corresponding decrease in deaths from trauma.
While this doesn’t conclusively prove that mercury is the sole cause of the increase in infectious disease deaths, the study “strongly suggests that mercury is part of the problem,” said study author Rosie Williams, a postdoctoral researcher at the Zoological Society of London.
The harbor porpoise is a marine mammal related to dolphins and whales and is considered a “sentinel species,” animals that indicate the health of the ecosystem and signal potential risks.
The authors of the latest study in the journal Environmental Science and Technology warned that the findings could also have implications for humans.
“Harbor dolphins are small, shy and easily overlooked, but their tissues silently record the story of our chemical footprint in the sea,” Ms Williams said. Speech.
“If top predators in UK coastal waters are becoming more polluted, the same processes may be affecting some of the fish and shellfish we eat.”
Mercury levels in shallow ocean waters have tripled since the industrial revolution due to human activities such as burning fossil fuels.
Mercury then accumulates throughout the food chain, particularly affecting predators such as porpoises, which build up mercury levels in their tissues.
Ms Williams said: “A safer ocean for dolphins and humans can be achieved by eliminating coal more quickly, reducing industrial emissions and moving away from products containing mercury where safer alternatives are available.”
