Latest Issue of Science News


Arctic melting may help parasites infect new hosts

Grey seals are encountering a killer microbe as they move north

NEW NEIGHBORS  As the Arctic emerges from a deep freeze, parasites including Sarcocystis pinnipedi (shown, purple) are able to infect animals that they have never encountered before.

CHICAGO— Along with melting Arctic ice comes an erosion of natural barriers that once separated parasites from hosts.

That erosion has allowed at least two pathogens to infect marine mammals they were previously unknown in, said Michael Grigg, a molecular parasitologist at the National Institutes of Health in Bethesda, Md. He reported the findings February 13 at the annual meeting of the American Association for the Advancement of Science.

A newly identified parasite was once frozen safely away from grey seals (Halichoerus grypus). It has now infected some with disastrous consequences. In 2012, about 20 percent of healthy-looking grey seal pups born on Hay Island off the coast of Nova Scotia mysteriously died. The cause turned out to be a parasite that destroyed the livers of 404 pups and two adults, Grigg said.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

This article is available only to subscribing members. Join SSP today or Log in.