A Review of the Effects of Seamounts on Biological Processes

Seamounts interacting with oceanic currents create flow complexities which depend upon current speed, stratification, latitude, and seamount morphology. Seamount effects, which include internal wave generation, eddy formation, local upwelling, and closed circulation patterns called Taylor columns, have important effects upon pelagic and benthic ecosystems over seamounts. The biological effects of these current-topography interactions are poorly understood. Flow acceleration on upper flanks of seamounts may lead to low sedimentation but areas of high standing stocks of benthic fauna, particularly filter feeders. Other effects extend into the water column; nutrient enrichment and enhanced primary productivity occur over some seamounts. Longer observational periods will be necessary to understand the time-varying nature of such enhanced productivity and the extent to which it remains at the seamount or is advected away. At higher trophic levels, unusual patterns of distribution and abundance occur at some seamounts. Maintenance of high standing stocks of seamount-associated micronekton and demersal fishes suggests that seamounts are locations for high rates of energy transfer. The energy driving this biological productivity may either be generated from in situ processes or be advected from elsewhere and concentrated at the seamount; interdisciplinary studies will be necessary to better understand these ecosystems.