A bay on the coast of Bordelais, famous for its oysters. In July 2008 80% of the baby oysters died after an especially virulent outbreak of a common herpes virus. This was followed in August 2008 by an onslaught by poisonous microalgae. This resulted in a ban on the harvesting, transport, sale and consumption of oysters from the shallow bay, west of Bordeaux. Arcachon bay has been prized for its oysters since the 4th century and their cultivation there was developed 150 years ago. It provides, inone form or another, all the oysters reared in France:. Only a small proportion of the full-grown ones but almost all the oyster fry used in the beds of Brittany, Normandy, Charentes-Maritime and the Mediterranean are provided from Arcachon. Global warming is thought to be contributing to some of these problems, with increased micro-plankton which allows the young oysters to fatten up, making them more susceptible to the herpes virus. A special, so-called 'mouse test' is used routinely in oyster fisheries in Europe to test the safety of the shellfish. This requires that liquid from oysters is injected into mice. If two out of three die then the oysters are declared unfit for human consumption. Recent;ly the mice have been dying even though the microalgae cannot be detected in the bay, giving rise to fears that there is some unknown threat which remains undetectable. This may be the product of ships dumping waste from other oceans, or global warming. The producers say that the mouse test is over-sensitive and that the closure of the beds is an over-reaction. The test is the equivalent of a human sitting down to eat 1000 oysters, so this is not a test in nature.