Asian mussel found in Carinthia as invasive species spread

A mussel species from East Asia has been detected in the Drau loop near Villach, adding to the invasive species spreading through Carinthia’s waters, ORF reports. The coarsely ribbed basket mussel can produce up to 5,000 offspring in a year.

It reached Carinthia via the Danube and has so far only been recorded in the Drau loop near Villach.

The mussel filters material from the water, including algae and phytoplankton. That can affect entire food webs by reducing the basic food supply for other organisms, said Benjamin Berntatz, an aquatic ecologist at the Carinthian Institute for Lake Research. In extreme cases, fish could also run out of food, he said.

Quagga mussel numbers rising

The quagga mussel, which originates from waters near the Black Sea, has been established in Carinthia for several years. Its numbers are increasing significantly and it can alter the ecosystems of lakes.

“They have not spread to new bodies of water. Their density has increased in the waters where they occur,” Berntatz said. The extreme example is Lake Ossiach, where quagga mussels are now very common.

Heat and a lack of rain are also putting pressure on Carinthia’s waters and their inhabitants. Other introduced species, including the quagga mussel and the mud crab, are spreading as well.

Sports equipment can spread species

Further spread of the introduced species is considered unlikely to be prevented. Diving and sports equipment, stand-up paddleboards and boats can carry them from one body of water to another if they are not properly cleaned or dried.

Whole mussels, very small individuals that are difficult to see and free-swimming larvae can all be transported, Berntatz said. Wherever water is carried from one place to another, the larvae can be carried with it.