The quantity of crabs is determined by their weight. We take one kilogram of crabs and count the individuals. Then, we weigh the entire catch and use the initial count to estimate the total number of crabs.
In theory, yes, Chinese mitten crabs are edible and they are even considered a delicacy in China. This has led to the export of live crabs from Europe to China, where they fetch a high price.
However, for most European consumers, the yellowish, slippery flesh of the crabs is rather unappealing. Most crabs are also still very small when we catch them, making them tedious to eat. Furthermore, these crabs inhabit the bottom of large rivers and canals, which are often polluted with heavy metals and other toxins. Larger Chinese mitten crabs in particular tend to be heavily contaminated with toxins.
The trade of Chinese mitten crabs is prohibited under European law as they are classified as an invasive species. Selling or giving them to restaurants is illegal.
In addition to health and legal concerns, we aim to discourage the trade of these crabs to prevent further spread of the species to other areas.
The handling of the crabs varies by country, as each has different regulations and guidelines.
In Belgium for example, the current catches of Chinese mitten crabs are frozen and either used for DNA analyses or send to zoos to be used as animal feed.
Within the CLANCY project, we are investigating different ways and practices to humanely handle, process and make use of the crabs for different means (beside animal feed).
No, the trap is specifically designed to catch only crabs. The Chinese mitten crab can’t swim and crawls along the riverbed. Once they enter the pipes of the trap, they are stuck and directed to walk through the tunnel to the trap basket.
Other aquatic species can swim or escape from the small slot in the pipes. Entering into the trap basket itself would mean they need to leave the water, which of course they are not able to do.
Managing the Chinese mitten crab is crucial for several reasons. As an invasive species, they significantly disrupt local river ecosystems. They compete with native species for food and habitat and cause damage to fishing gear and water infrastructures, such as riverbanks and water intake pipes.
By controlling the Chinese mitten crab populations, we protect the biodiversity of our aquatic ecosystems, preserving native species and their habitats to ensure the health and balance of the environment.