On Sat, 18 Jul 2009 22:50:40 -0400, Wizard of Woodstock
wrote:

I've got to believe that there is some kind of preventative measure
they can take to lessen their impact on water intakes and such.

Engineering will eventually solve the water intake issue. Lake
Ontario has been a huge success story as far as I can see and local
residents agree. The lake is cleaner/clearer now than any time since
the early 50s and I'm seeing signs that other fresh water shell fish
are coming back also. When I was a kid Lake O's beaches were covered
with small shells at certain times of the year but that all went away
in the 60s as pollution of various types took over.