Herpes is not just for humans to suffer through.

Modification of a picture by David Monniaux

Modification of a picture by David Monniaux (Photo credit: Wikipedia)

Is global warming killing off oyster populations? Experts say it is a good possibility. The incurable, deadly virus is, however, alarming fishing communities in Europe, where oyster herpes seems to be spreading and could go on spreading as seas continue to warm.

This story is not new but should be a reminder of the fragile eco system we all live in.

Herpes-infected shellfish is not new to science, but in 2008—the first year a huge increase in mortality rates was detected in France—Ifremer detected a new variation of the virus.

Like the other strains of herpes that affect mollusks, OsHV-1 μvar attacks young oysters during breeding season, when the mollusks’ bodies are so focused on producing sperm and eggs that the oysters have no energy to maintain an immune system.

But OsHV-1 μvar is “more virulent than strains we identified before,” adding that the virus is so efficient at killing its hosts that it can wipe out 80 percent of the oysters in a bed within a week.

That death rate is the only outward sign something’s wrong, because an oyster herpes have no visible symptoms, and diagnosis is possible only through lab testing.

Could Oyster Herpes Spread?

To keep the U.K. oyster-herpes outbreak from spreading, the British government has banned the shipping of oysters out of affected areas, most of which, like Whitstable, are around the mouth of the River Thames in southeastern England.

No matter what measures are taken, oyster herpes is going to be tough to beat. Even if all the infected Pacific oysters are removed from oyster farms, wild Pacific oysters will still be present in surrounding waters, perhaps acting as “a reservoir for infection.”

It’s unlikely, though, that OsHV-1 μvar would end up in U.S. oyster beds, because the United States doesn’t typically import oysters from Europe. But it will up the demand for oysters from the U.S. which will lead to further damage to the eco-system.

But a less virulent, herpes-like virus has been detected in farmed oysters off California. If sea temperatures continue to rise, perhaps μvar or something like it could emerge in U.S. waters too.Image

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