Invasion in the stream: signal crayfish threaten local wildlife!

Invasion in the stream: signal crayfish threaten local wildlife!

The American signal crayfish is spreading into German waters at a pace that makes us sit up and take notice. Most recently, this invasive cancer was caught in a stream near Werdohl, like WDR reported. This species not only poses a threat to the native crayfish, but also to frogs, toads and small fish. Up to 40 signal crabs were caught in a trap set up by the Märkischer Kreis Nature Conservation Center under the direction of Volker Knipp. A total of seven such traps are set up along the water, each 15 meters apart.

The traps are simple: they are filled with dry dog ​​food, which attracts the signal crabs. They can be recognized by their reddish color and a size of up to 18 centimeters. Gourmets are particularly pleased because signal crayfish are considered tasty. But their impact on the local wildlife is devastating. These invasive crayfish are increasingly displacing native crayfish and can endanger the habitats of many other species.

Dangers for the local fauna

The problems caused by signal cancer are complex. With a higher growth rate and propensity to reproduce, as well as an aggressive lifestyle, this species has devastating consequences for the local ecosystem. In addition to the noble crabs, fish fauna, vegetation and other small animals are also affected, such as Noble crab project NRW explained.

A particularly worrying detail is that the signal cancer is spreading in large quantities in the Ennepetalsperre and reaching the Märkischer Kreis via the Ruhr and the Volme. This prevalence could continue to increase, particularly if climate change weakens future climatic barriers. There are already around 900 established neobiota species in Germany today, many of which, like the signal crayfish, can have a major influence on their new habitats BfN reported.

Combat measures

Volker Knipp emphasizes that it is essential to catch and kill these crabs in order to protect the local fauna. After the trapping operation, the traps must be cleaned thoroughly to prevent the spread of diseases such as crayfish plague or salamander plague. Sometimes the caught crabs are given to people who enjoy eating them or to hunters who use them as food for wildlife.

The situation surrounding signal cancer shows that we have to be vigilant. The spread of invasive species is a sign of the changes our waters are experiencing due to climate change. It is up to us to accept the challenges and protect the biodiversity of our homeland.