Dispersal strategies of benthic species and water current variability in the Corsica Channel (Western Mediterranean)

Macrofauna and their dispersal strategies were identified in the fouling communities settling on current meter moorings deployed in the Corsica Channel. Oceanographic arrays provided time series of water current and substratum for colonisation of fauna. Larvae, sexual propagules, juveniles have different lengths of the planktonic phase. Some of these strategies are time-limited but others could survive indefinitely in the plankton. Current measurements indicate that fluxes are directed northward with reduced variability in direction and some fluctuations in magnitude with greater speeds in winter. The Corsica Channel is a one way gate for water fluxes from the Tyrrhenian Sea toward the Ligurian Sea. This gate could be "open" or "closed" for biological transport if length of planktonic phases and magnitude of current are consistent with the distances that dispersal forms have to travel to reach a suitable habitat. Strategies with an "unlimited" planktonic phase are less influenced by current variability.