In an alarming revelation, researchers looking to Hawaii's coasts have determined that the concentration of mercury found in common commercially caught fish is climbing at a rate of nearly four percent per year. (Photo : Flickr: p.Gordon)

In an alarming revelation, researchers looking to Hawaii's coasts have determined that the concentration of mercury found in common commercially caught fish is climbing at a rate of nearly four percent per year.

That's at least according to a study recently published in the journal Environmental Toxicology & Chemistry, which paid particular attention to yellowish tuna caught in North Pacific commercial fisheries.

"The take-home message is that mercury in tuna appears to be increasing in lock-step with data and model predictions for mercury concentrations in water in the North Pacific," lead author Paul Drevnick, from the University of Michigan Biological Station and School of Natural Resources and Environment, explained in a statement.

These model predictions were based on assessments of atmospheric mercury release caused by industry - namely smelting and the widespread burning of coal for power - and were compared to historical records and published reports on yellowfin tuna (Thunnus albacares) caught near Hawaii over the past half century.

The resulting data showed that indeed, mercury concentrations have been rising since the industrial revolution, and have yet to plateau.

"This confirms that mercury levels in open ocean fish are responsive to mercury emissions," Drevnick added.

If nothing is done, he and his colleagues warned, the current "business as usual" of industry could double concentration of the toxic metal in the Pacific by 2050.

And that would fly directly in the face of a pledge recently made by 120 countries to fight the threat of mercury poisoning on a global scale. The pledge, made and renewed at last September's UN General Assembly, tacked on even more promises for the "The Minamata Convention on Mercury."

The convention was designed to have nations working together to reduce industrial mercury emissions and prevent another tragedy like the one that occurred to the Japanese city of Minamata in 1956, which resulted in at least 54 cases of mercury poisoning. Most of those cases resulted in death or devastating cognitive impairment within the year.

Experts have argued in the past that aside from pursuing ways to reduce mercury pollution via safe industrial practices, regulative attention should be brought to atmospheric emissions, namely those from gold smelting and coal burning.

"Future increases in mercury in yellowfin tuna and other fishes can be avoided by reductions in atmospheric mercury emissions from point sources," Drevnick and his colleagues pressed.

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