Recent studies have revealed the presence of methylmercury – a strong toxin- in Antarctic ice in the Southern Ocean. The research was published in the journal Nature Microbiology. It is the first survey to show that bacteria present in the ice can replace mercury with methylmercury, a more toxic form. This can harm the environment, fish, and birds too.
If ingested by humans, the methylmercury goes to the brain, causing impaired development and physical problems in children, and fetuses.
The shocking discovery was made by an international team led by Ms. Caitlin Gionfriddo and Dr. John Moreau, from the University of Melbourne.
The toxic chemical spreads fast through the food chain as large fish prey on smaller fish and the methylmercury builds up in their bodies, reaching levels harmful for consumption by humans.
The team tried to understand better how that toxic form of mercury enters the marine environment and into the food chain.
It took two months of hard work aboard the Aurora Australis icebreaker, for Ms. Gionfriddo to collect Antarctic sea ice samples.
The ice was taken for analyses at several universities in the US and Australia. Mercury is a heavy metal, highly dangerous, created by eruptions or bushfires. Sometimes it is manmade, through activities like gold smelting or burning fossil fuels.
The results showed that the bacteria present in sea ice have the genetic ability to turn mercury into the more toxic form. When mercury is burned or released into the atmosphere, it stays there for a year and sometimes disperses on long distances. Mercury can spread over thousands of kilometers.
This bacteria is called Nitrospina and can produce methylmercury.
The metal concentration in the Antarctic Ocean increases during spring when sunlight boosts the amount of mercury which is found in the environment.
Apparently, this is nature’s way of warning us not to bring mercury into the Antarctic ice environment. If the ice is going to melt faster, a lot more mercury will contaminate the fish which live in the area.
What’s your opinion on this matter? Do you think the fish you eat could contain mercury? Is that a major reason for concern? Leave a comment below and tell us what you think. Thank you.
Image Source – Wikipedia