Report: Mercury Levels Rising In Popular Types Of Tuna

DETROIT (WWJ) - A new report says mercury in certain popular varieties of Pacific Ocean tuna is rising.

That's despite the fact that, experts say, atmospheric pollution from early 1970s through the late 1990s levels has remained constant.

"The ocean is very big and it might've taken that amount of time of releasing that amount of mercury to actually see the mercury increasing in the fish," explained Paul Drevnick, a former University of Michigan researcher and current water quality scientist in Alberta, Canada.

"In the Pacific Ocean, in water, it's about 3 percent per year of an increase," from 2002 to 2008, he said. "In the fish, it's about the same; something like 3 to 5 percent."

While mercury is a metal found naturally in the environment, scientists believe human activities such as coal burning can increase the mercury cycling through the air, water, and soil. Fish absorb the mercury, humans who eat those fish take it in, and at high levels it can be harmful.

Drevnick says both Bigeye and Yellowfin tuna — which are often marketed as "ahi" and are widely used in sushi and other raw fish dishes — have seen rising levels.

What's being done about it?

Drevnick said the United Nations has come down with some new rules to crack down on mercury pollution. He said many nations have already ratified the restrictions and, once they go into effect, it should reduce mercury levels globally.

In the meantime, it may be a good idea to consider reducing your tuna intake.

Along with tuna, commercial fish known to contain higher levels of mercury include king mackerel, Marlin, swordfish, shark, tilefish and orange roughy.

[Get more information on mercury in fish, including how much is safe to eat of which varieties, from the EPA at this link].