Benthic-pelagic coupling under juvenile oyster influence in a French Mediterranean coastal lagoon (Thau Lagoon)

The aim of the present work was to test influence juvenile oyster culture on benthic-pelagic coupling in French Mediterranean Thau Lagoon. Although period growth induces introduction millions oysters lagoon over a short duration, effects water-column and benthic ecosystem are poorly known. Using multiple ecological approach, water column parameters, sedimentation rates, sediment characteristics fluxes were monitored three occasions during pre-growth period, from October December, at two sites inside farming area outside that served as reference. In column, results showed significant lower ratio between total phytoplankton biomass (chlorophyll-a) degraded pigments (pheopigment), increase contribution containing chlorophyll-b (ie chlorophytes) decrease chlorophyll-c (mainly diatoms) farm sites, attributed grazing pressure caused by large particles, described for adult oysters. No effect observed interface this due dispersion small quantities biodeposit produced juveniles low temperature conditions. A multivariate approach supported revealed trend conditions with being distinct reference ones. long history could have shaped properties such areas maintain different