Lionfish, which have spines that contain venom, are a well-known problem in Atlantic coral reefs. These invaders from the tropical parts of the Pacific and Indian oceans have no natural predators in the Atlantic Ocean. They are eradicating many fish populations in the shallow reefs that they have overtaken. Recently, the overwhelming problem has proven worse than originally thought.

Between 2009 and 2011, the team of scientists from tested nasal swabs from more than 900 marine mammals from 10 different species off the Pacific Coast from Alaska to California.

They detected H1N1 infection in two northern elephant seals and antibodies to the virus in an additional 28 elephant seals, indicating more widespread exposure. None of the infected seal showed any clinical signs of illness