Certain invasive exotic species, such as the red swamp crayfish, are harmful to our environment because they nibble on aquatic plants, dig burrows in banks, and transmit crayfish plague to native species. «But there are also non-native fish and crayfish that are not harmful and do not need to be controlled,» ecologist Pim Lemmers argues in his Ph.D. thesis, which he will defend at Radboud University on 30 May.
Certain invasive exotic species, such as the red swamp crayfish, are harmful to our environment because they nibble on aquatic plants, dig burrows in banks, and transmit crayfish plague to native species. «But there are also non-native fish and crayfish that are not harmful and do not need to be controlled,» ecologist Pim Lemmers argues in his Ph.D. thesis, which he will defend at Radboud University on 30 May.
The red swamp crayfish has a bad reputation, and not without good reason. «It really is the worst,» says Lemmers. «It walks on land, destroys aquatic plants, and digs into banks, to the detriment of water quality. It is a real problem.»
The spinycheek crayfish, on the other hand, is currently causing far fewer problems in the Netherlands. It does not burrow in banks, although it did in the past transmit crayfish plague, thus contributing to the drastic decline of European crayfish in the Netherlands.
