The Pacific oyster, Crassostrea gigas, well known throughout the world because of its ability to adapt to a wide range of environmental conditions, was introduced for cultivation into France on a massive scale in the 1970s. With global warming, the reproductive population, confined at the beginning to the south of the French Atlantic coast, became established at more northern latitudes (above 45 degrees 58'N), and wild C gigas began to colonize coastal areas such as our study site, Bourgneuf Bay (1 degrees-2 degrees W, 46 degrees-47 degrees N), an oyster-farming site. An original approach, based on orthophotograph analysis and in situ biomass sampling, revealed that, in the northern part of this bay, more than 70% of the total C gigas biomass was composed... |