Jellyfish and mussels

Alien life in our lakes is causing a stir

Upper Austria has once again achieved top results in the ranking of bathing water quality in our lakes.

(Bild: Marion Hörmandinger)

At the start of summer, Upper Austria's bathing waters once again shine with peak values. However, newly colonized and not entirely unproblematic creatures in our lakes are causing a stir. 

Summer can now officially begin, as 39 of our 43 EU bathing water sites were rated "excellent" and four were rated "good", meaning that none were rated "poor". This was checked by the Agency for Health and Food Safety Linz at the beginning of June.

The main purpose of the inspection is to ensure safety. We have beautiful bathing spots in Upper Austria and want everyone to be able to swim without hesitation

Umwelt- und Klima-Landesrat Stefan Kaineder

However, newly colonized organisms in our waters are causing some excitement. Among other things, the quagga mussel, which was introduced from abroad, is spreading rapidly in our lakes. Nikolaus Schobesberger, an expert in water quality control, explains: "Once it's here, you can't get rid of it, so we're trying to prevent it from spreading to all our lakes."

Provincial Councillor for the Environment and Climate Stefan Kaineder and Head of the Water Quality Inspectorate Sabine Kapfer take a water sample from Lake Traunsee

(Bild: Reinhard Hörmandinger )

This mussel species is not without its problems: "On the one hand, our fish population will suffer in the future as the quagga mussel filters out its food source. On the other hand, it is also very sharp-edged, which leads to more abrasions," says Schobesberger.

Facts and figures

The quagga mussel was originally common in tributaries of the Black Sea. It was brought to Austria by ship and boat traffic. The mussels, which are around 40 millimetres in size, usually attach themselves to stones. They have already colonized the Attersee, Traunsee, Mondsee and Feldkirchner Badesee lakes.

But this is not the only new arrival in our waters. An increasing number of freshwater jellyfish can now also be found. They also have stinging cells, but only for small prey such as insect larvae. This is why they cannot cause any damage to human skin. It has already been detected in Lake Pichling and the Feldkirchen bathing lake, among others.