Parts of Berlin have been overrun with scuttling red crayfish that are likely trying to expand their territory, a German conservation network announced on Thursday.
The invasive red swamp crawfish have been spotted scuttling around the paths of the Tiergarten park and even parading outside the neighboring Spanish Embassy.
The red critters are often spotted in the park, but they have been appearing in much larger numbers this year, picking up considerable attention on social media.
The Nature and Biodiversity Conservation Union (NABU) said it has received large numbers of sighting reports in the past weeks. It said the increased numbers are problematic for the ecosystem of Berlin.
The Tiergarten population of the non-native crayfish likely took hold from people dumping them in the ponds there. They are a popular addition to aquariums given their striking appearance and their hardy nature.
Measurements by the fisheries office revealed that the water quality of Tiergarten was quite high, meaning the crayfish were probably migrating due to population expansion.
The North American species often squeeze out local populations of crayfish and carry diseases. They were labeled as an invasive species of high importance by the European Commission last year.
NABU, Germany's largest nature conservation group, called on aquarium owners to refrain from releasing exotic animals into Berlin's water systems.
Under poaching laws, it is forbidden to catch and grill the tasty crustaceans.