Zeesla en bodemdieren in het Veerse Meer

The soft bottom of the Veerse Meer is characterised by sea lettuce vegetations in the shallow zones and the presence of a rich benthicfauna, especially in these shallow parts. High mortality of bottom invertebrates in the yearly exposed zone between MSL and MSL-O,70m, 'and the exposure of large masses of Sea lettuce can be prevented in the future with a fixed waterlevel on MSL. The poverty of benthic fauna in the deep gullies is a consequence of stratification, causing anaerobic conditions. Solutions for the oxygen depletion, aimed at lowering the stratification by an as large as possible exhange with salter water from the North Sea or Oosterscheldt, combined with a reduction of the polderwater discharge on the lake, are therefore beneficial. By consequence, the higher and more stable salinity willincrease species richness and the musselbeds, until now only marginal, will have better chances to develop. Sea lettuce seems not to be influenced in the future by the different possible management alternatives and therefore we can not expect its production to decrease.