Zebra mussels in the estuaries of Black Sea are limited only by the
available surface area and the salinity. I did some grab sampling and can
attest that they pave the bottom in some areas. They are killed when
salinity reaches more the 6 parts per thousand. The larvae have trouble
settling in water velocities above 1 m/sec. There is no indication that
there is a natural predator that has significant effect in controlling their
numbers, although some ducks and fish are known to eat them. I can guarantee
that if a fish is imported to eat zebra mussels, it will also eat native
species of mollusks.
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Gary Rosenberg, Ph.D.                     [log in to unmask]
Malacology & Invertebrate Paleontology    gopher://erato.acnatsci.org
Academy of Natural Sciences               http://www.acnatsci.org
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