according to Dr. James Carlton, no marine organism, once established, has
ever been successfully removed or eradicated in the US. New introductions can
cause problems for native species such as predation, competition,
disturbance, and diseases and parasites.
There now may be an exception, an exotic sabellid worm which was
devastating abalone population on the West Coast. A localized population was eliminated below
the detection level by eliminating the intermediate host.