TEMPO.CO, Washington - The rise on ocean surface temperature caused by the climate changes may increase the mercury level in fish. It will also higher the health risk for sea food lovers.
Mercury is one of heavy metals which can cause several damages to human organs such as nerves, brain, kidney and can even cause cancers. Researchers in United States revealed that air-borne mercury which is released into air as the result of industrial pollutions can accumulate in the rivers and oceans, and transforms into methyl mercury, a highly poisonous substances.
Researchers from Dartmouth College and other institutions in the US have studied the killi fish under varying temperatures both in laboratory tanks and in salt marsh pools in Maine. Fish in marshes ate insects, worms and other natural food sources, while the lab fish were fed mercury-enriched food. In a report published by PLOS ONE journal, the result showed the fish in warmer waters ate more but grew less and had higher methyl mercury levels in their tissues, suggesting that increases in their metabolic rate caused the increased uptake of the toxic metal.
Big fish eat the smaller ones and take up all the mercury which was contained in the smaller fish. "This increase can be propagated to higher tropic level fish consumed by humans, resulting in increased human exposure to MeHg (methyl mercury)," said the researcher as quoted from ABC News, Oct 4.
Mercury gets into fish body through polluted water filtered by the fish gills. The longer the fish lives, the more mercury is accumulated. The researchers said this harmful effect should be incorporated into policy and management efforts aimed at reducing human health risks from MeHg exposure.
ROSALINA | ABC NEWS
