This was said by a spokeswoman for the International Lake Constance Fishing Federation (IBF) in the run-up to the annual general meeting in Friedrichshafen on Saturday.
Although the fishermen caught larger quantities of the fish last year than in the worst year so far, 2019. “But the first five months of fishing in 2022 indicate a further decline in the whitefish population,” said the spokeswoman. “Hardly any fishermen go to the lake to catch whitefish at the moment, because it’s not worth it.” The few fish caught are often too thin.
There are many reasons for the decline in catches. On the one hand, the low phosphate content of Lake Constance, located at the border triangle between Germany, Austria and Switzerland, leads to less zooplankton as food for the whitefish.
On the other hand, according to the Baden-Württemberg Ministry of Agriculture, an immigrant fish species, the stickleback, has been eating up more and more plankton since an explosive increase in numbers a few years ago – and the quagga mussel draws more and more nutrients from the water.
Cormorants also contribute to the problem, according to fishermen. In the meantime, around 900 breeding pairs lived in at least eight colonies on Lake Constance, said the IBF spokeswoman. “In summer up to 4,000 cormorants eat in the lake, in winter there are around 1,500 birds.” They’re now harvesting more fish than all the fishermen together catch in a year. For more than twenty years, fishermen have been calling for the number of fish-eating migratory birds to be regulated – if necessary, by shooting them down.
“We professional fishermen on Lake Constance feel let down, no matter what the issue,” said the IBF spokeswoman. The future of professional fishermen is therefore “anything but rosy,” said the association spokeswoman. “If things continue like this, the trend of more and more fishermen giving up their profession will continue.” At present, only 63 fishermen on Lake Constance have a deep-sea license, i.e. permission to fully engage in fishing. In the 1980s there were still 180.