Mytilopsis leucophaeta
A brackish water zebra mussel Mytilopsis leucophaeta was
identified from Cardiff docks, in South Wales in late 1996 (Oliver,
Mettam & Holmes in press). The full size range of individuals
has been found, and it appears to be established in Wales
.
This species was described from Belgium (under a different
name) in 1835 and is present in other European countries, but it is
not clear whether it has arrived in Britain from the continent or
its native America. This find is of particular interest as a fresh
water member of the zebra mussels (Dreissenoidea), Dreissena
polymorpha, has caused considerable problems in the North American
Great Lakes by smothering other species, habitats and commercial
property.
In the Aquatic Nuisance Prevention and Control Act 1990, which
was enforced to prohibit the release of freshwater ballast into the
Great Lakes, it was estimated that the effects of the zebra mussel
will have cost $5,000 million by the year 2000.