Life in the benthic boundary layer: connections to the mid-water and sea floor

Abstract

The abyssal benthopelagic zone is enriched in biomass and numbers of species, relative to the overlying water column. It is inhabited by (i) pelagic species whose ranges are truncated by the sea bed, (ii) normally benthic species who use the zone as a refuge, for dispersal or for locating their food, (iii) a specialized fauna, which includes many novel species with primitive characteristics. The increase in the standing-crop in the zone is related to the greater availability of organic material on the sea bed, and the extent of its resuspension and diffusion from off the bottom. Several species are known to be capable of responding to both predictable and erratic pulses of input, but otherwise their physiologies seem to differ little from other pelagic and benthic species. These communities contribute a small but significant percentage of the benthic recycling.