With the arrival of zebra mussels in the Great Lakes more than a decade
ago, local, national, and international attention have focused on
the establishment of non-native, invasive or nuisance species in freshwater
and marine habitats. Aquatic plants like water chestnut, hydrilla,
and Eurasian water milfoil choke local lakes, adversely affecting
recreational activities, and depressing lakefront property values.
The Asian shore crab has become the dominant intertidal crustacean
in the Northeast, displacing both native and non-native crab species;
its omnivorous diet includes juvenile mussels, other crabs, and seaweed.
Marine tunicates foul boat lines, dock pilings, and are causing problems
for some shellfish industries. The pathways for species from their
native habitats to new ones are many, including ballast water, recreational
boats and bait buckets, live seafood shipments, discharges of unwanted
aquarium organisms, and other intentional as well as inadvertent means.
It is a global problem costing enormous ecological and economic problems.
