Pilot project aims to keep lake free of invasive species
Species that are not native to Switzerland can spread widely and cause problems - and are almost impossible to remove. A pilot project now aims to protect Lake Pfäffikon in the canton of Zurich from alien species.
In Switzerland, alien species - so-called neobiota - are increasingly spreading. These introduced or immigrated animals and plants can cause considerable damage to humans, animals, infrastructure facilities and the environment. They can also cause problems in water bodies by spreading rapidly and displacing native species, for example. This poses a significant threat to biodiversity.
Through transmission of the crayfish plague, for example, large American crayfish have already driven native noble crayfish to local extinction. Other neobiota such as Black Sea gobies are displacing native fish species from their spawning and feeding grounds. In turn, alien mussels such as the basket or quagga mussel clog up pipeline systems.
Lake Pfäffikon as ideal test area for pilot project
Lake Pfäffikon in the Zurich Oberland is a popular local recreation area. Today it is a functioning ecosystem and provides a habitat for numerous rare and endangered plants and animals. Fortunately, it has hardly been colonized by alien species to date.
Since the nearby Greifensee and Lake Zurich are already infested with some invasive neobiota, new species are also expected in Lake Pfäffikon. To prevent this, the Office for Waste, Water, Energy and Air (AWEL) is implementing the pilot project "Neobiota Free Zone Pfäffikersee" in consultation with local communities and associations.
The aim of the project is to keep the lake as free as possible from harmful alien species and to preserve the valuable current ecosystem. Because once they have established themselves, they can hardly be removed.
Raise awareness and demonstrate correct behavior
Raising awareness among fishermen, boat owners and water sports enthusiasts plays an important role in the pilot project. They can unintentionally introduce invasive species from other waters, as neobiota can stick to boats, other floating bodies and equipment or be carried along in bilge water - the residual water in the lower hull of the boat - or in water residues in the equipment. Therefore, boats must be carefully cleaned before entering Lake Pfäffikon, and the same applies to the rest of the equipment. In addition, live bait fish must not be allowed to enter Lake Pfäffikon from other lakes.
In addition, the local public will be made aware of the issue of neobiota and the consequences of illegal releases of aquarium and garden pond inhabitants. The measures will be implemented from 2016 to 2018, adjusted if necessary and evaluated. In 2019, a balance sheet will be drawn up and a decision made as to whether the measures should be continued and, if necessary, extended to other bodies of water in the canton of Zurich. The pilot project on Lake Pfäffikon provides important findings for the cantonal neobiota strategy, which can also be used throughout Switzerland.
