Like the tiny atmospheric particles he studies, Dr. Joe McConnell's latest research study has been slowly permeating the news, finally wending its way to my inbox. We marine-types are so often starved for long-term data that the thought of a 200 year record makes us salivate. That's one benefit of working on ice cores in Greenland instead of fish. The ice doesn't move around so much.
But back to the data. Lead, cadmium, and thallium are all nasty, bioaccumulating toxics that are released by burning coal. Lo and behold, when the world started burning coal in the 1860s to fuel the industrial revolution, heavy metal deposition also spiked and stayed high until the 1940s, when the world's engines began shifting to oil and gas. The lead peak stretched out a little longer, with high contamination levels lasting until the 1970s. What changed in the 1970s? The passage of the Clean Air Act and the advent of unleaded gasoline.
Once heavy metals like these and our good friend mercury are freed up into the atmosphere getting them out of circulation is difficult, if not impossible. So the best way to keep heavy metals out of your fish is to keep them out of the air and water in the first place. The Greenland ice cores show that human activities can affect far away ecosystems, for worse and for better. Which means we should all be concerned about the rapid growth of coal-fired power plants in China. That includes you, big catcher-processor boats hoping to take advantage of an ice-free arctic to plunder new fishing grounds. Nobody wants toxic arctic cod.
The Desert Research Institute provides the full article here