Yes, San Diego Joe as a good point.
Mussels reproduce by sending their infants into the water to incubate in the
gills of fish. This doesn't hurt the fish. They then drop to the bottom and
live out their lives.
So if your water is leaving your pond they will to.


kathy :-)
algae primer
http://hometown.aol.com/ka30p/myhomepage/garden.html