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Because of the low level of the waters, several cantons are beginning to fish. The fish are briefly stunned.
Along the stream with a net, bucket and electric fishing gear. The Schlimmbach in Kriens in the canton of Lucerne is the first stream from which fish have to be rescued this year. Philipp Amrein, head of the fisheries department in the canton of Lucerne, explains: “The water has receded rapidly in the last few days. Now we still have the opportunity to get the fish out with relative effort. We assume that there will be no more water in here in 24 to 36 hours. »
Legend:
The small brown trout are placed in a kettle full of water. The water is enriched with oxygen. This is how the fish survive until they are released into the neighboring stream.
SRF
The emergency fishing happens with a so-called electric fishing device. In order to be able to catch the fish, they are stunned briefly, then they are put into the net and from there into the kettle. The aim is to bring the fish – in Kriens it’s brown trout – to the nearest body of water. The water in the boiler is enriched with oxygen for transport to the village stream in Horw. A body of water is selected that should still have enough water in the next few days.
If there is no water left, we have to take the fish out by hand.
The oxygen content is also a key factor in deciding where to fish. Little water and a high water temperature in a stream lead to a low oxygen content. Amrein: “If we don’t do anything, the fish will suffocate.”
In Lucerne, the water authorities inform the canton of the water level. Employees of the cantonal office then decide on the measures. «It’s better for the fish to fish now, when the water is still flowing. If there is no more water, we have to remove the fish by hand, which puts even more stress on the fish,” says Philipp Amrein.
Legend:
An employee of the cantonal office is looking for fish in the Schlimmbach in Kriens. The fish are briefly stunned by the electric fishing device.
SRF
The Schlimmbach is the first stream in the canton of Lucerne to be fished. But certainly not the last: “This week there should be a few more. We look every day.”
Even grayling in “heat stress”
Another means that is decreed when the water levels are low is the ban on water withdrawal. The cantons of Thurgau and Freiburg have already imposed one. In many other cantons, the withdrawal ban applies to certain bodies of water.
On the Rhine in Schaffhausen, it is the water temperature in particular that worries the authorities. The temperature of the Rhine is currently 25 degrees Celsius. Stefan Lebeda from the Department of the Interior of the canton of Schaffhausen tells the SDA: “The graylings get heat stress from a temperature of 23 degrees. The lethal range is a water temperature of 26 degrees for a few days.” In 2003 and 2018, for example, there was a major fish kill. “There are currently no signs of this,” said Lebeda. As an immediate measure, the farmers are no longer allowed to take water from the Biebern. This tributary to the Rhine brings relatively cool water.
Legend:
A picture that the authorities do not want to see this summer: in 2018, many dead fish will have to be pulled out of the Rhine.
key stone
Structural measures for cooler water
In the canton of Baselland, too, three streams already have to be fished out. And on the lower reaches of the Birs, the authorities of both Basels are taking a special measure: In order to minimize the stress on the fish and prevent fish from dying, there is a bathing ban for humans and animals from today, Tuesday. Baselland is also trying to counteract this with structural measures. Deeper pools and trees along the banks are said to keep the water cooler.
In the canton of Aargau, special attention is paid to Lake Hallwil. Here, the level drops by one centimeter per day. Therefore, the outflows like the Aabach are now reduced to a minimum.