The mountainous area is laced with a network of small faults as well as an active magma chamber located beneath the region, which also contributes to the frequency of its seismic activity. A French marine biologist has discovered that oysters react to stress in much the same way as humans, and secrete hormones when they are under pressure, affecting their immune systems and leaving them more vulnerable to disease. The attacks from stress often occur as the shellfish are being harvested in metal baskets and then transported on an often rocky boat ride to market. Those hormones are the same as those found in humans. Lacoste began researching the problem after oyster breeders along France's western coast reported an abnormal rise in oyster mortality during the past five years.
Oysters are a huge business in France, and are an important part of the country's traditional menus.
The high mortality rate has been caused by the vibrio splendidus microbe, which hit the oyster farms in the early 1990s. Although it first appeared in insignificant quantities, it later spread swiftly through the maritime environment, wiping out thousands of oyster beds. Lacoste discovered that some oysters infected others with the microbe as they were being moved. Their stress levels all rose at the same time, causing the germ to spread rapidly among vast quantities of the shellfish. 2001 Discovery Communications Inc.