"The pulsing environment is hostile to zebra mussels at every stage of their life cycle, greatly reducing their numbers" Hmmm, just how is it "hostile" to the mussels? Why does it just "reduce their numbers" rather than exterminate them completely? What I am wondering, of course, is whether some individual mussels are not exterminated because they do not find such an environment hostile - and whether within a few generations those resistant mussels will be genetically selected, producing a new strain of zebra mussels which are not affected by this technology?? Like an antibiotic which "greatly reduces" numbers of bacteria, resulting in strains of bacteria which are resistant to the drug. It will be interesting to see. Paul M.