The dredge is non selective, therefore, sea
stars are collected as well as oysters and
scallops as the dredge passes over the sea
bottom. Sea stars then need to be picked out
by hand to be disposed of later. There are
dredges with slight modifications such as the
“roller dredge”, which uses a front roller to
suspend the sea stars before collecting them
in a rear bag, and the specialized dredge
used in France to selectively collect Asterias
rubens.
The dredge is best used for medium to small
scale areas with high densities of sea stars.