PRODUCTION AND ENERGY BUDGET IN MARINE SUSPENSION-FEEDING POPULATIONS- MYTILUS-EDULIS, CERASTODERMA-EDULE, MYA-ARENARIA AND AMPHIURA-FILIFORMIS

The pelagic primary production and the secondary production of four sp ecies of benthic suspension feeders were frequently measured over a pe riod of approximately one year in four different habitats. Simplified energy budgets over one-year periods are presented including ingestion , absorption, faeces production, respiration and secondary production. The production of a Mytilus edulis culture exceeded primary productio n by about 6.25 times, whereas semi-exposed shallow-water populations of Cerastoderma edule and Mya arenaria had a production roughly equal to primary production. In an exposed area, the latter species had a se condary production:primary production ratio of 0.15:1, whereas for a d eeper-living (40 m) Amphiura filiformis population this relation was 0 .0034:1. M. edulis followed by C. edule and M. arenaria in the semi-ex posed habitat had the comparatively lowest Respiration:Absorption rati os and the highest Production:Absorption ratios. This study emphasizes the ecological importance of horizontal advective processes for energ y transfer from the pelagic to the benthic system.