Hey. Do you know what that picture up there is? It’s a map of Mercury. Excuse me, it’s the first-ever map of the surface of the closest planet to the sun. Pretty amazing, right?
First it was arsenic in our chicken. Now mercury in our dolphins? If you needed further evidence that the world is a dangerous place for humans and non-humans alike, this is it: a recent study by scientists from Johns Hopkins found that wild dolphins roaming the oceans around Florida had significantly higher levels of mercury than their captive counterparts.
That’s (presumably) because captive dolphins are fed a diet of smaller fish from New England and points north, while Gulf Coast dolphins eat, well, Gulf Coast fish. And Gulf Coast fish are full of Gulf Coast pollution, most notably mercury-laden fumes from nearby power plants.
The larger issue here is that mercury, while very pretty to look at, can do scary things to the human (and dolphin) brain and nervous system. That’s why the FDA advises pregnant women and children to limit their intake of high-mercury fish. The mercury gas puffed out by coal- and oil-fired power plants travels from the air to the ocean and then on up the food chain, which is where the dolphins come in.
“This is just one snapshot, one puzzle piece,” says Edward Bouwer, head of Hopkins’ Department of Geography and Environmental Engineering, and co-author of the study. “What we’d like to do now is repeat this project with aquariums in other parts of the world. The goal is to get a clearer comparison of mercury-related health risks facing dolphins both in captivity and in the wild. This type of research can give us hints about how the type of diet and where it originated can affect mercury-related health problems in captive dolphins, compared to their cousins in the wild.”
One ray of hope for the dolphin lovers out there: the EPA recently adopted stricter standards for air pollution from power plants, the major source of the mercury contamination in our oceans.