Lake Constance Suffers from Invasive Species Threatening Local Fishing Industry
For over 30 years, Reto Leuch has been fishing with his nets in Switzerland’s Lake Constance. However, he has noticed that in recent years, there are fewer and fewer food fish, such as perch, due to invasive species that have taken over the lake, such as the stickleback fish and quagga mussel. According to Leuch, these invasive species directly compete with local species, depriving them of food and making fishing unsustainable in the Swiss lake.
The situation in Lake Constance is being studied by German, Austrian, and Swiss scientists, who are measuring the populations of invasive species and their impact on the ecosystem. They have identified 37 species of invasive animals and plants in the lake. One example is the quagga mussel, which originated from the Ukraine and likely arrived via cargo ships through the Rhine-Danube Canal.
Silvan Rossbacher, a researcher at the Swiss Federal Institute of Aquatic Science and Technology, said that in the most infested areas, there are about 30,000 mussels per square meter. This is due to the quick reproduction of the invasive species, such as the sticklebacks, which now represent 90% of the fish in the lake.
The total budget for the project to study and address the issue of invasive species in Lake Constance is 5,666,477 euros, with aid from the European Union’s cohesion policy of 2,248,708 euros. Seven research institutes from the three riparian countries are involved in the project.
However, according to Piet Spaak, a researcher and director of the SeeWandel project, it may already be too late for Lake Constance. He suggests that individuals can help by ensuring that they do not transport quagga mussels or larvae from one lake to another.
The invasive species also filter the lake water, affecting its clarity and quality. With Lake Constance being a reservoir of drinking water and a vital tourist center, the issue of invasive species must be addressed urgently to protect not only the fishing industry but also the lake’s ecosystem and human health.