Inter-Research > MEPS > Prepress Abstract

MEPS prepress abstract   -  DOI:

Seasonal dynamic of the benthic food web in subtidal sandbanks

A. E. Robert*, N. Quillien, M. Bacha, C. Caulle, M. Nexer, B. Parent, T. Garlan, A. Carpentier, R. Amara, N. Desroy

*Corresponding author:

ABSTRACT: Submarine sandbanks are widespread worldwide but, paradoxically, these ecosystems and their dynamics remain largely unknown. As submarine sandbanks are targeted by a large variety of human activities, it is urgent to provide sound scientific knowledge for Environmental Impact Assessments (EIA) and an appropriate management of biodiversity in these areas. To our knowledge, the present study is the first to investigate the seasonal dynamics of the benthic food web in sandbank areas. We performed a stable isotope analysis in the French part of the southern North Sea. In the area of massive phytoplankton blooms, we found a very simple food web structure that is heavily dependent on organic matter particles in seawater. Primary consumers, that is deposit feeders and, to a lesser extent, suspension feeders, dominate the benthic biomass. Small predator-scavengers such as annelids, shrimps and crabs prey upon them. Fish predators such as Echiichthys vipera represent a very restricted proportion of the biomass. We observed that the general structure of the food web is relatively well preserved over seasons. We thus suggested that the ecosystem functioning is resilient to natural disruptions - such as dune migrations - and probably to anthropogenic disturbances.