Meiofauna of the Belgian coastal waters: spatial and temporal variability and productivity

Density, biomass and diversity of meiobenthic assemblages have been studied in the Belgian coastal waters of the North Sea since 1972. Near-shore sediments east of Ostend show an extremely poor meiofauna, with nematodes extremely dominant. West of Ostend muddy sand and sands exist with a richer fauna. These zones are clearly delimited on the basis of nematodes, whereas they are more uniform when either macrofauna or harpacticoids are studied (Govaere et al., 1980). This is alsa true for off-shore sediments. Besides species diversity also trophic diversity, as expressed by the number of feeding types, increases towards off-shore sandy sediments.The study of density and biomass of nematodes and harpacticoids permits estimations of production of these groups. The total carbon requirements of the meiobenthos can be estimated at 8-9 g C/m².year in the coastal zone and a minimum of 5-6 g C/m².year on the Kwinte bank, a subtidal sandbank, although sedimentation is very much lower in the sandbank. This indicates that when energy flow is lower a much larger part of it passes through the meiobenthos