The current ecological situation of the upper estuaries of Eider, Elbe, Weser and Ems is heavily stressed. This is shown using the indicators tidal range, forland area, oxygen concentration in the water column and heavy metal concentration in sediments. Compared with a historical situation very strong losses of estuarine habitats and strong increase of the tidal range are evident. Compared with the situation 20 years ago, there are different developments. On the one hand, improvements can be noted in the heavy metal burden and the oxygen content in Weser and Elbe as a result of emission-reducing measures. On the other hand, there is a dramatic deternation of the oxygen situation in the inner Ems estuary. A weak further increase in the tidal range and destruction of foreland still takes place in the estuaries.
Restoration of estuarine water quality and habitats is necessary for all estuaries, also as a requirements of implementing habitat and water framework directives. Different kinds of measures have been already performed and also monitored; examples of different measures and ecological consequences will be shown. It becomes obvious, that regeneration of estuarine habitats is possible within certain limits, but must be adopted to the specific situation along the estuarine salinity and turbidity gradient.
Although integrated management plans are under work or already finalized in the framework of directives, implementation of restoration measures remains a challenge. Further need for research is obvious.
