Video transects reveal that tidal sand waves affect the spatial distribution of benthic organisms and sand ripples

The sandy seabed of shallow coastal shelf seas displays morphological patterns of various dimensions. The seabed also harbors a rich ecosystem. Increasing pressure from human-induced disturbances necessitates further study on drivers of benthic community distributions over morphological patterns. Moreover, a greater understanding of the sand ripple distribution over tidal sand waves may improve morphological model predictions. Here, we analyzed the biotic abundance and ripple morphology in sand wave troughs and crests using video transects. We found that both the epi- and endobenthos are significantly more abundant in sand wave troughs, where ripples are less abundant and more irregularly-shaped. Finally, we show that camera systems are relatively quick and effective tools to study biotic spatial patterns in relation to seabed morphology.