This chair has been inaugurated in 2014. The ideas of developping an exchange platform on river issues dates back much longer. The holder of the Chair, Karl M. Wantzen, is performing research on rivers since 1990, when he studied the sediment fauna of the River Rhine, establishing the freeze- core technique in the diving chamber lowered from a large vessel. The large chemical accident of Sandoz of 1986, releasing toxic spills in large quantities and killing a large part of the fish and invertebrate faunae, had resulted in a an increasing awareness of how sensitive riverine ecosystems are. At that time the Rhine was not delivering substantial protein food for the human populations along the river any more (Salmon, Sturgeon, Allis shad had gone extinct long before) but the painful view on hectares and hectares of killed eel, tench and other fish had gone through the media and shocked the large public. Our freeze core studies showed that river ecosystems may partly recover from strong disturbances such as Sandoz, given that essential natural dynamics are still working. We found out that even in larger systems as the Rhine, there is a „river below the river“, named hyporheos, from which animals can recover, given that they are small enough to live in the crevices. Eel and tench, however, took longer to come back and many species known from the early 20th century have gone forever a long time ago. The Rhine of today is a roundabout for invasive species and the authochtonous diversity can only partly recover. We have changed the rules that decide over ecosystem functioning and over occurrence of species by putting the rivers into straight corsets, alienating their natural habitat structures by concrete, by changing the natural flow regime through damming, diking and water withdrawal and by injecting harmful substances into them. Most rivers in Europe have lost their rhythm and their character today.

 

Along with the loss of biological species and hydrological rhythm, the rivers are losing their cultural character. Nobody wants to live next to a polluted river. Fish migrations, once gone, do not trigger cultural events such as fisheries celebrations any more. The people do not live „with“ the river any more, they live „against“ it. „If you choose a river as your neighbour, you must not be surprised if this neighbour pays you a visit from time to time“, and old word says. Blind belief into the allmightyness of dike structures has made us blind to see the risks of natural and – more recently – climate-change-driven river dynamics. This loss of contact with the nature, and, the negative connotiation of natural issues such as floods is a bad starting point for a sustainable management.

In many Southern Countries, the situation is – still – different. Studying streams and rivers in the Paraguay-Paraná River system in the heart of Latin America, including the enourmous wetland of the Pantanal, covering nearly 200.000 km² of floodplain, since 1993, gave me the occasion to study how rivers may function. However, these large natural units are currently endangered at an unrivalled extension. We once succeeded to hold an illegal spread of the „hidrovia“ project to deepen the Paraguay river main channel for navigation in 1999, but who knows when this mega-project will come back into discussion? Brazil has one of the finest legislations to protect riparian zones in the world, but application is not always warranted, and the recent development of the Forest Code and  its interpretation are more than worrying. The extension of natural or near-natural sites in the Tropics is larger than in Europe, but the menaces do also have much wider geographic scales, let alone the Arc of Deforestation threatening Amazonia, or the skyrocketing numbers of dam constructions and transformation of wetlands all over the Tropics. While studying details of stream ecology during my PhD thesis, entire populations of stream fishes collapsed, some of them including even undescribes species. It became more than evident form me that environmental scientists are ethically obliged to dedicate at least a part of their expertise and capabilities to save a part of nature. We love it because we know it, thus we have to protect it.

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