Biodiversity links above and below the marine sediment-water interface that may influence community stability

Linkages across the sediment-water interface (SWI) between biodiversity and community stability appear to exist but are very poorly studied. Processes by which changes in biodiversity could affect stability on the other side of the SWI include carbon transfer during feeding, decomposition of organic matter, nutrient recycling, organism recruitment and structural stabilisation of sediments. The importance of these processes will clearly vary among habitats. Direct disturbance to communities on one side of the SWI, such as created by overfishing, habitat destruction, and species invasions, has the potential to impact communities on the other side of the SWI through the many functional links. Hypotheses are proposed to suggest further areas of research to fill the large gaps in our knowledge concerning the nature and intensity of such linkages. The linkage between benthic and pelagic diversity is likely to be tighter where there is a close energetic connection between the domains, such as polar and shallow coastal waters, and where communities are dominated by selective detritivores. The quantity of carbon reserves in the sediment and the predominant mode of larval development of sediment communities probably influence the stability of below SWI communities in the face of changes in above SWI diversity. The organisms, including hyperbenthos, that are found at the SWI may be of crucial importance to the linkage and stability of above and below SWI communities.