Report: Macrozoobenthos: Weser Fatigue (1973)»
Description
In 1968, in the Weser fatigue substrates and macrobenthos of the wadding and the river sole were mapped and measured in the stream channel chloride and seston contents of the water. The tide-dependent and seasonal variations in the Cl content are extremely large and characterise the Weser fatigue as distinctly poikilohaline waters. The substrates of the river sole are very different (sludge to boulder) and distributed regello. They have a very sparse and stretchwise no settlement at all. The sediments of the wadding are zoned from soft soils in the inner estuary to pure fine sands on the sea side and along the stream channel. The vegetation of the free cottons is poor. In the mesohaline section (according to mean values), mass development of Nereis and Corophium prevents the development of soil diatoms. More important are Vaucheria species, which form a multi-kilometre-long felt. Most plant material provides a denser, the wadding framed ruby straightening belt. The macrofauna of the wadding consists of 26 marine, 13 brackish, 1 limnic and 6 other species. The majority of marine species in the estuary show a deviating behavior towards the substrate: Either spread over all types of soil (biotope expansion) or switch to another, e.g. from soft to sand soil (biotope change). According to this phenomenon, the binding of many soil animals to soils of certain grain sizes is not as narrow as is often assumed. Striking is the closeness of the distribution of most marine species and Limnodrilus, whereas the habitats of the specific brackish water species are fragmented and dissolved at the borders. The number of species decreases by sea, not as steadily changing numbers of individuals and biomass. For the latter, the values are significantly lower than those known by marine wadding. A progressive impoverishment of nutritional types reaches its extreme in the settlement area of the specific brackish water forms (predominantly oligochaetes). Especially here in the center of the cloud of cloud suspensions are missing, and substrate and epistrate eaters are the groups present alone. Inspections carried out in 1973 revealed local damage to soil fauna. They point to a deteriorating milieu in the Weser fatigue caused by the wastewaters of chemical industries.
Resources
| Name |
Format |
Description |
Link |
Tags
- makrozoobenthos-abundanz-makrofauna-artenzusammensetzung-nlwkn-biologische-kartierung-sedimentologische-kartierung-poikilohalin-kronos-titanwerk
- wesermündung-weser-nordenham