Utilization of seston flux over a mussel bed

A combined sampling approach was used to address the topic of utilization of the nearbed seston field over a natural bed of the blue mussel Mytilus edulis.Samples taken by a new device, the Benthic Organic Seston Sampler (BOSS), were combined with near-bed current information and in situ clearance rate measurements to assess the effect which the Mytilus bed had on the horizontal seston flux.During mid ebb-tide the mussels were capable of processing the flow within 7 cm of the seabed, but only utilized about 20 % of the seston flux available within that region.The possibility that significant refiltration occurs suggests that the actual effective 'feeding zone' of the mussels was on the order of 3.5 cm.Chlorophyll and carbon analyses and direct cell counts indicated that the mussels fed preferentially on high concentrations of resuspended benthic diatoms, depleting the bottom 3 to 5 cm of this rich food resource.