Sabellaria alveolata is a tube-building gregarious polychaete that constructs large biogenic reefs. In macrotidal shellfish ecosystems, this species competes for food with cultivated suspension-feeders. The suspension-feeding activity and clearance rate of S. alveolata were investigated in response to changes in seston concentration. A flow-through system was designed to study 225 cm(2) reef blocks with more than 500 individuals. The experimental conditions were characterized by increasing concentrations of suspended particulate matter ranging from 6.5 to 153.8 mg L-1, while the organic content of the diet (microalgae Skeletonema costatum) decreased inversely from 49 to 9%, to mimic the dilution of organic matter by inorganic particles, characteristic of... |