Warmer waters potentially exacerbated by climate change have become a fertile breeding ground for a new strain of herpes threatening the western European oyster industry.
The strain, Ostreid herpes virus 1 (OsHV-1) μvar (mew-var), preys on young breeding Pacific oysters and can decimate as many as 80 percent of a bed's oysters in a week, according to National Geographic. It is dormant until water temperatures surpass 61 degrees F (16 degrees C), leading European experts to speculate that climate change may explain the new virus's appearance.
Oyster herpes can't spread to humans, but dead oysters are unsafe to eat. The human variety is typically linked to the Herpes simplex viruses, but other forms of herpes can impact clams, scallops and other mollusks. There are no symptoms of oyster herpes, so it can only be detected through laboratory testing.
The new strain attacked French oyster beds in 2008, 2009 and 2010, killing between 20 percent and 100 percent of some oyster beds. The incurable virus has also killed Pacific oysters in Ireland and the U.K., but native species appear to be unaffected. The U.K. instituted a ban restricting movement of oysters from infected areas.
A less virulent strain has surfaced in California farmed oysters. Researchers doubt OsHV-1 would show up in the U.S. because it rarely imports European oysters.
Image CC licensed by Flickr user lanchongzi.