Tidal sand waves and benthic organisms: observations and modelling of bio-physical interactions

The sandy seabed of shallow coastal shelf seas (e.g. North Sea) displays fascinating morphological features of various dimensions. At the same time, the seabed also harbours a rich ecosystem. It is well established that benthic community composition is related to various abiotic variables, such as sediment grain size and bed shear stress. However, less is known about how macrobenthic species relate to morphological bed patterns, and in particular to tidal sand waves. Increasing pressure from offshore human activities makes it necessary to further study the drivers of benthic community distributions over sand waves. Moreover, a greater understanding of the effects of benthic organisms on hydrodynamics and sediment transport processes over sand waves may improve morphological model predictions. In this contribution, we will present a combination of field observations and process-based modelling techniques that are used to determine and understand the effects of the feedbacks between benthic organisms and sand waves.