The French oyster industry has been devastated by the abrupt die-off of juvenile oysters; this summer, oyster farmers watched in dismay as between 40 and 100 percent of their young oysters were wiped out. Now researchers say they’ve found the cause of the mysterious blight: The oysters have been infected with a herpes virus for which there is no known cure.
A warm winter and wet spring left the young oysters especially vulnerable to Oyster Herpesvirus type 1, they say. They matured too fast, feeding on abundant plankton, the scientists say. [French oyster expert Tristan Renault says] that “the animal has been using up a lot of energy developing its genitalia and using a lot less to defend itself” [BBC News].
All of France’s oyster breeding areas, of which 90 percent are on the western coast, are affected by high mortality rates except one area at Arcachon in the southwest. Scientists do not know why Arcachon oysters have been spared [Reuters]. Researchers say that oyster farmers might be able to replenish their stock by breeding the uninfected Arcachon oysters, which could have some resistance to the wide-spread disease.
Consumers haven’t been affected yet, because oysters take several years to grow big enough to eat. But researchers say that the harvests of 2009, 2010, and 2011 will be sharply reduced as a result of the infection. The incident has been viewed as a looming gastronomical crisis in France, where oysters are often served with lemon and white wine. In July, Agriculture and Fisheries Minister Michel Barner … urged research scientists at France’s marine research institute to mobilise all its resources [AFP] to fight the deadly oyster scourge.