What are ecologists and biologists doing to limit the mitten crab population?

In many areas, where they migrate upstream, crabs are
caught in screens usually by dams and discarded. In many places, it is illegal to have
or transport live mitten crabs. Bilge water in boats and ships must be carefully cleaned
to avoid infesting other waters when the bilge water is released. Traveling screens have
been placed in areas like dams when the mitten crabs are migrating in an attempt to
capture them. In some places, commerical fishing of these crabs and exportation to Asia
is encouraged as a method of control, because they are considered a delicacy there.
However, they are very destructive due to their burrowing nature and attempts to control
them have met with little success in both Europe and North
America.