A new study suggests that mercury concentration in the common commercial fishes of Northern Pacific is increasing at an alarming rate. Researchers, studying the coasts of Hawaii, have found this increase to be nearly 4 percent per year. The study has been published in the journal Environmental Toxicology & Chemistry and it mainly focused on yellowish tuna caught in North Pacific commercial fisheries. Lead author Paul Drevnick, from the University of Michigan Biological Station and School of Natural Resources and Environment explained “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.”
The assessment of atmospheric mercury, released by the industries, formed the basis of these model predictions and comparison was made with historical records and published reports on yellowfin tuna, which were caught over the past half century near Hawaii. The results of the analysis showed that since the industrial revolution, the mercury concentrations are indeed increasing. Drevnick commented “This confirms that mercury levels in open ocean fish are responsive to mercury emissions.”
If the current trend of industries continues and no steps are taken in this regard, the concentration of the toxic metal in Pacific might double by 2050. Recently 120 countries have pledged to fight the threat of mercury poisoning on a global scale. Last September the pledge was renewed at the UN General Assembly, adding more promises for the “The Minamata Convention on Mercury.” The convention aims at collaborating the efforts of nations for lowering the industrial mercury emissions and preventing tragedies like the one which occurred to the Japanese city of Minamata in 1956. At least 54 cases of mercury poisoning were found in the incident, most of which resulted in either death or devastating cognitive impairment.
According to the experts, apart from promoting safe industrial practices for reducing mercury pollution, efforts should also be directed towards reducing atmospheric emissions, especially from gold smelting and coal burning. Drevnick and his colleagues commented “Future increases in mercury in yellowfin tuna and other fishes can be avoided by reductions in atmospheric mercury emissions from point sources.”