The Roth, a rather small stream in the municipality of Schwabhausen, has developed into a very lively river in terms of flow speed after the heavy downpours in the past few days. Günter Schön, the future tenant of the Rothbach, would like to see a lot more life in it. Volunteer as a beaver advisor and nature conservation guard for the Lower Nature Conservation Authority Dachau and also active as a mussel advisor for the Upper Bavaria district, he is starting a long-term pilot project - to reintroduce the brook mussel in the Roth.
Schwabhausen
- In this project he will work closely with Dr.
Bernhard Gum from the Upper Bavarian District / Fishery Advisory Service, working together with the Chair of Aquatic Systems Biology at the TU Weihenstephan and the Bavarian Shell Coordination Office.
Also involved are the chairmen of the Roth II and III water boards, Georg Burgmair and Simon Sedlmair.
The river mussel used to be native to the surrounding waters, but 90 percent of all stocks in Bavaria have now disappeared.
At a first meeting, the general conditions and prerequisites were determined to what extent the river mussel can be made at home again in the Roth.
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There is evidence that the brook mussel was one of the earlier inhabitants of the Rothbach.
© Höltl
Since mussel shells have already been found in this stream in the past, one can say with certainty: They have been there before.
For Dr.
Bernhard Gum, who, among other things, also set up the mussel coordination office in Bavaria, the basic data - such as the gravelly subsoil and the appropriate water quality - are “a great potential for the project”.
It's a long-term process and it will take some time before the first results can be seen, but “what are three or four years for nature?” Günter Schön points out.
The course for this project is now being set step by step.
The course of the stream was examined together on that day.
Slight meanderings (river loops) through small back areas enhance the course of the water.
It would be ideal if each section had a diverse design using roots and wood and woody trees accompanying the stream could take over the shading and cooling.
Electro-fishing is then carried out in spring with representatives of the TU Weihenstephan so that the fish population can be recorded and examined quickly and gently.
Depending on the remaining fish population, suitable host fish are stocked for the river mussel.
The next step is then stocking with fish that are already "afflicted" with glochidia (mussel larvae).
This is repeated several times, and then one hopes for the first successes in the search for young mussels.
Everything that is done in the upper reaches of the Roth has a positive effect on the entire stream, as the current carries the fish and also the mussels and glochidia downwards.
It would be important for Günter Schön that the existing seven concrete falls are removed in order to ensure the ecological balance, since the Roth, as the largest side stream of the Glonn, is particularly important.
At the moment these falls prevent the fish from rising out of the Glonn and the Rothbach cannot be used as spawning water.
The river mussel reintroduction project is unique as it has never been attempted in this way.
"It will be exciting", Schön is sure and will also receive full support from the community with Mayor Wolfgang Hörl.
Roswitha Höltl