Mercury levels in sea water rising due to global warming, warn scientists
Posted on: 30/Jan/2017 4:56:17 PM
Scientists have said that rising temperatures may boost levels of mercury - one of the world’s most toxic metals - in fish by up to seven times the current rates. They have found that extra rainfall drives up the amount of organic material flowing into the seas. This alters the food chain, adding another layer of complex organisms which boosts the concentrations of mercury up the line.
According to the World Health Organisation, mercury is one of the top ten threats to public health. The substance at high levels has been linked to damage to the nervous system, paralysis and mental impairment in children.
The scientists recreated the conditions found in the Bothnian sea estuary. They discovered that as temperatures increase, there is an increased run-off of organic matter into the world’s oceans and lakes. Speaking about this, they said, This encourages the growth of bacteria at the expense of phytoplankton. When bacteria become abundant in the water there is also a growth of a new type of predators that feed on bacteria. You basically get one extra step in the food chain and methylmercury is enriched by about a factor of ten in each such step in the food web.The study was published in the journal Science Advances.
