Four years of monitoring were carried out on intertidal sedimente and bottom fauna in the Weser estuary around Nordenham, where since 1969.large amounts (c. 20 000 to 30 000 m3 /day) of waste water from a Titaniumdioxide factory are discharged. The main constituents are H2SO4 and FeS04, the pH-value is between 2 and 2.5. The results could be compared with a base-line study from the time before the beginning of the discharge. The main results, summarized as annual mean values of the. parameters investigated quantitatively, are given in table 8. The main characteristics of the area investigated are salinities low in average but widely fluctuating, highly turbid water, very soft muddy sediments containing high amounts of clay, organic matter and several chemical compounds, and the presence of a largely impoverished bottom fauna. From the 26 species occurring 16 are of marine and four of limnic origin, the remaining six are indigenous brackish water species. According to the instable environment, species combination changed continuously, particularly dependant on river discharge and changing salinity. A particular interest was attached to the development of iron content in the deposite during the discharge of iron-acid wastes. There was a certain rise in several years which, however, was not continuous. With regard to the ecological effects it was concluded, that drastic changes in species diversity and total biomass have not occurred, while total abundance has declined close to the waste water outlet but in certain other areas has increased. Concerning species combination, it became evident that one species which had been abundant before the beginning of the discharge, the brackish water crustacean Neomysis. integer, has disappeared.
Die Zukunftsinitiative -Wasser in der Stadt von morgen- (ZI) baut auf der Zukunftsvereinbarung Regenwasser und dem Masterplan Emscher-Zukunft auf. Im Mittelpunkt der Initiative stehen die Handlungs- und Gestaltungsmöglichkeiten, die mit dem Planungsleitbild der integralen Wasserwirtschaft und einer wassersensitiven Stadt- und Quartiersentwicklung verbunden sind. Sie hat das Ziel, die Entwicklung und Gestaltung der Emscherkommunen unter sich ändernden Rahmenbedingungen (Strukturwandel, demographischer Wandel, Klimawandel) zukunftsfähig und nachhaltig zu gestalten.
