DRIFTING MEIOBENTHIC AND MACROBENTHIC INVERTEBRATES ON TIDAL FLATS INKONIGSHAFEN - A REVIEW

Many benthic species have been recorded to occur in the water column a bove the tidal flats in Konigshafen. They were either passively suspen ded from the sediment or performed active migrations. Concerning both number of species and organisms, active migrations were more important . The causes for these migrations range from (1) individual escape fro m a sudden threat such as predator attack, over (2) group evasion of l ocal subpopulations to avoid environmental deterioration, to (3) habit at changing of entire populations. The temporal scales involved range from seconds to seasons, and the spatial scales from cm to km. Such ch anges of distribution patterns have been demonstrated in juvenile moll uscs and in meiofaunal copepods and plathelminths. Since migrations ma y interfere with many kinds of population studies in the field, new me thods and concepts need to be developed to avoid and overcome pitfalls . As a precaution, the migration potential of benthic species should b e taken into account in any field study including population parameter s.