The effect of ribbed mussels (Geukensia demissa) on the planktonic community of coastal embayments. A mesocosm experimental approach

J PAN; RM CERRATO; DJ LONSDALE

Puerto Madryn

Jornada; VI Jornadas Nacionales de Ciencias del Mar; 2006

Top-down controls exerted by the benthic suspension-feeding community are of major importance in shallow coastal embayments and marshes. The ribbed mussel, Geukensia demissa (Mytilidae), has the potential to feed on planktonic food sources of a broad range of sizes. In order to analyze preferences for different planktonic groups, we performed grazing experiments with mesocosms. Control and treatment mesocosms (8 mussels per 59-litre container) were assembled in situ in early summer, using ambient seawater from Quantuck and West Neck Bays (Long Island, USA). Water samples were taken at T0 and Tfinal (2.5 h) for different analyses. Relative filtration efficiency was assessed through partitioning the plankton into total, >20ìm, 20-5ìm and