Alarm on Lake Garda: Invasive catfish threaten native species!

Alarm on Lake Garda: Invasive catfish threaten native species!

Lake Garda in Italy, a popular destination for tourists and divers, is facing a serious threat from invasive species. This picturesque lake, particularly known for its clear waters and spectacular shoreline landscapes, is increasingly being plagued by a variety of invasive species that are threatening the local ecosystem. Divers and fishermen are noticing a worrying increase in these species, especially in the northern area around Riva del Garda.

A local diving group documenting underwater life and ecosystem challenges is sounding the alarm. Invasive species that are multiplying rapidly include crabs, mussels and particularly threatening “monster” catfish, which can grow up to three meters long and are displacing endemic species. Fishermen on Lake Garda have already pointed out this problem, as the huge catfish not only reduce fish stocks, but also attack other animals such as waterfowl and small mammals.

Threat from giant catfish

The giant catfish are spreading particularly in the areas between Sirmione and Lazise, ​​thereby endangering the ecological balance of the lake. According to Marco Brognoli's divers, the conditions in Lake Garda are ideal for the reproduction of these catfish: clear water, shallow shore areas and high water temperatures enable the population to grow quickly. During a dive last year, Brognoli and friends were able to catch 14 catfish within just 200 meters. The catfish also disrupt the reproductive cycles of native species, especially bass, whose spawn is eaten.

The situation is compounded by other invasive species such as the Louisiana red crayfish (Procambarus clarkii) and the quagga mussel. The Louisiana red crayfish, also known as the “alien shrimp,” is particularly voracious and difficult to control. Its natural predators, such as seagulls, herons and some species of fish, cannot keep up with the species' rapid reproduction. The quagga mussel, known in Lake Garda since 2023, deprives the water of nutrition and increases oxygen consumption, causing further damage.

Reactions and recommendations for action

The alarming situation has sparked concern among environmentalists and tourism operators. While fishermen are demanding a structured containment strategy immediately, there are proposals to set up collection and disposal points for catfish, similar to wild boar regulation, to provide remuneration to fishermen. It has already been observed that in other Italian regions such as Mantua, lakes have been almost emptied by invasive species, which has also led to a decline in tourism there.

Lake Garda therefore faces not only ecological but also economic challenges. The future of the lake now depends on a rapid and effective regional policy response to preserve the fragile balance of the ecosystem and ensure the positive impact on tourism. Experts warn that without appropriate measures, the beauty and attractiveness of Lake Garda is at significant risk.