Andrew-

I think you'll find at least a partial answer to your questions at
http://sgnis.org/publicat/cjf11_2.htm.  You'll also find that less
trafficked bays have a much small exotic assemblage than larger bays,
although individual species can be quite pervasive.

Best,

Chuck

Charles L Powell, II
Western Earth Surface Processes Team, MS 975
U. S. Geological Survey
345 Middlefield Rd.
Menlo Park, CA  94025
[log in to unmask]
(650) 329-4985



                      Andy Rindsberg
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                      02/02/04 10:11 AM
                      Please respond to
                      Conchologists of
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Here's a question for Conchlers who are familiar with shelling in
California bays. I've read that incoming ships often dispose of their
ballast water too close to shore -- it's illegal but they usually don't get
caught. This releases large numbers of foreign larvae into the local bays,
some of which have become dominant locally. This is an intriguing
phenomenon and it makes me wonder:

1. Do all the bays end up with the same dominant introduced species of
mollusks, or does every bay end up with a different mix?

2. Are the smaller, less showy species being replaced as quickly as the
larger ones?

3. Is the molluscan fauna of smaller, less trafficked bays, like Mugu
Lagoon or Elkhorn Slough, changing as much as that of large bays like San
Francisco Bay?

The answers could have a good deal of ecologic signficance, and might also
suggest future trends. I realize that most Conchlers are more interested in
collecting in clear Florida water than in bay mud, but maybe someone out
there knows a thing or two!

Andrew K. Rindsberg
Geological Survey of Alabama