Altérations des peuplements benthiques de roches profondes en Méditerranée nord-occidentale : quelque aspects biologiques et molysmologique

Dives with the submersible Cyana in 1990 on Saint-Julien shoal (off Saint-Tropez) confirmed observations made in 1987 of damaged benthic communities on deep rock substrate (> 80 m). On the NE side, gorgonian populations had suffered an apparently catastrophic mortality, related to sedimentation of particulate matter carried along by the Ligurian current. Heavy metals and PCB contents of the sponge Reniera plana collected on opposite sides of the shoal indicate heavier contamination on the side facing more intense sedimentation. Sponges may be useful for distinguishing particle-carried pollutants (accumulated in the tissues) and dissolved pollutants (fixed in the skeleton).