The role of bio-hydrodynamic interactions in determining the functioning of shallow, benthic ecosystems

Abstract

Epi-benthic organisms play a strong role in controlling pelagic-benthic mass transfer rates by directly modifying concentration gradients (i.e., production, or removal of material) and by indirectly modifying near-bed hydrodynamics. Focusing on these bio-hydrodynamic interactions, we will demonstrate how the physical structure of different assemblages, via their interaction with currents and waves, results in spatio-temporal variation in transfer rates at a range of scales. Examples will be used to highlight the, sometimes complex, interactions between organism/population properties (i.e, height, area, volume, flexibility, density and distribution ) and near-bed hydrodynamics. Innovative approaches for examining transfer rates under natural hydrodynamic conditions will demonstrate how these interactions can determine the transfer (and retention) of nutrients and particles between the water column and benthos, creating intra-specific micro-niches (or zones) with different physiochemical properties (potentially influencing biodiversity). Finally, inter-specific differences in bio-hydrodynamic effects will be discussed in relation to benthic processes (such as the burial of organic matter, i.e, the “blue carbon hypothesis”) and suggestions will be made about the potential consequences of changes in benthic habitat distribution for the functioning of shallow, benthic ecosystems. Oral presentation given at 2011 ocean sciences meeting (ASLO), San Juan, Puerto Rico (13-18-02-2011).