The Importance Of Primary Producers For Benthic Nitrogen And Phosphorus Cycling.

In shallow coastal systems where most of the seafloor lies within the photic zone, benthic photoautotrophy plays a key role in regulating nutrient cycling. In these systems, production of submerged vascular plants (seagrasses), macroalgae and benthic microalgae is high and typically exceeds that of phytoplankton (Borum and Sand Jensen 1996). Changes in the patterns of primary production as well as in habitat structure and trophic dynamics (Valiela et al. 1992; Nixon et al. 1996) have been directly related to nutrient over-enrichment; this is also recognized as one of the greatest threats to maintaining marine biodiversity in coastal regions (NRC 2000). [ABSTRACT FROM AUTHOR]