Even tiny amounts of mercury can wreak havoc on algae, with the effects being passed up the food chain and onto dinner plates.
Researchers at the University of Geneva have measured how mercury affects the gene expression of algae, even at levels generally considered safe by European environmental protection standards. Using molecular biology tools, it was the first study to explore mercury poisoning at the microalgae level.
The study, published in Nature.com’s Scientific Reportsexternal link on Tuesday, shows how mercury enters the food chain via Chlamydomonas reinhardtii, a green microalga that measures just six by ten microns. The Geneva-based researchers chose it because its genome had been fully sequenced, making it possible to observe the effects of mercury.
They discovered that exposure to methylmercury disrupted more than 5,000 of the alga’s genes – potentially putting fish that feed on it at risk. Humans that consume fish heavily contaminated with mercury can suffer severe neurological disorders.
Other animals are already suffering.
“It is a global problem since high levels of mercury have been detected in the blood of polar bears, far from any source of contamination. It is crucial, therefore, that we understand the governing mechanisms, both from an environmental and public health perspective,” wrote study leader Vera Slaveykova in a media releaseexternal link.