Report: Macrozoobenthos: Emsmündung Papenburg to Emden (1979)»

Discussion and summary: The investigation took place from June to October 1979. The study of the lower Ems between Emden and Papenburg showed a clear ecological breakdown into four sections, which are based on different species composition and upstream decreasing abundance and biomass. Only Section IV, the Leda, which flows into the Ems at Leerort, is an exception. Despite a further reduced number of species, population density and biomass are rising again. A possible cause of this phenomenon could be sought in the sediment condition. Summary: In the river Ems between Papenburg and Emden, which is the transition area from freshwater to lowly concentrated brackish water, a survey of the Macrozoobenthos fauna (including Oligochaeta) of the intertidal mudflats was carried out. In addition, salinity distribution, properties of the sediment and composition of the intertidal reed belts ere investigated. The whole investigative area shows a very pronounced uniformity of the substratum. In all stations the material is composed of mud in more or less soft consistency which contains a blend of sand only in the upstream area, close to the channel, or in the vicinity of sluices.