Netherlands: The province of South Holland wants to reduce the number of crayfish

The number of American crayfish has increased dramatically and is therefore a major problem in South Holland and the rest of the Netherlands. These crayfish, which do not occur naturally in the Netherlands, have a negative effect on biodiversity, the ecosystem and water quality. For example, the crayfish eats and destroys aquatic plants. This has consequences for animals that depend on these plants. The remains of the plants form sludge, which is bad for water quality. The digging activities of these animals also pose a potential risk to dikes and banks. Various studies have been conducted in recent years. These studies focus primarily on the negative impact of the crayfish on biodiversity and water systems. A perspective on how the problem can be solved is lacking. For example, it is unclear which design of the water system, for example adjustments to the bottom of ditches or to the waterfront, slows down the population growth of crayfish. Furthermore, no proven effective capture ...