Polar Bears are more an more affected by mercury pollution. How is this happening?

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kimfuji's profile pic

kimfuji | College Teacher | (Level 1) Associate Educator

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Polar bears are in a dangerous situation now due to the ice melting at a rapid rate of speed. They are spending much more time in the water than they used to. They used to spend most of their time on the snow and on masses of ice (glaciers). However they are melting. There has been a lot of media coverage on the effects of global warming on the survival of the Polar Bears.

The mercury they are ingesting is from the fish they are eating. 150 tons of mercury are added to the environment every year from coal-burning electric plants and incinerators.

The mercury ends up on land or in the water. It's absorbed by microorganisms. They convert it to methylmercury. This is  a very toxic compound. It accumulates in fish and when Polar Bears eat them,they're intoxicated by the large amounts.

The larger animals eat the little animals, then methylmercury becomes more concentrated-the process is referred to as  bioaccumulation.

giorgiana1976's profile pic

giorgiana1976 | College Teacher | (Level 3) Valedictorian

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First of all, it's important to establish from where the Polar Bear is feeding.The result was that from 2 cardinal food chains the Polar Bear procures it's nutrients, mainly:phytoplankton (microscopic plants which are floating on the ocean's surface) and algae.

According to studies, the phytoplankton is the principal source of nutrients for Polar Bear, but also having a higher amount of mercury than algae.

The dependency of the Polar Bear of ingestion of increasingly large phytoplankton quantities is the result of global warming, thus, the amount of mercury ingested is worrisome. 

It is not negligible the fact that ice and snow have their proven contribution to deposition of mercury, substance which is found in environment, naturally, as well as from sources generated by mankind. The mutation of mercury into the poisonous methylmercury is happening in microorganisms which, after that, are stored in fish and animals.

The dependency of the Polar Bear of ingestion of increasingly large phytoplankton quantities is the result of global warming, thus, the amount of mercury ingested is worrisome. 

versatilekamini's profile pic

versatilekamini | College Teacher | (Level 1) Valedictorian

Posted on

Mercury enters water naturally as well as through industrial effluents.It is a potent hazardous substance.Polar Bear is more affected by mercury polluction due to consumption of heavily mercury contaminated fish. From the effluents mercury compounds enter the water body and at their bottom these are metabolically converted into methyl mercury compounds by anaerobic microbes.Methyl mercury is highly persistent and thus accumulates in food chain.Methyl mercury is soluble in lipids and thus after being taken by animals it accumulates in fatty tissues.Fish accumulates methyl mercury ions directly and when Polar Bears eat them they are more affected by mercury

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