crappiedoc,
Luckily, the mortality rate for veligers is very high! Each female can produce 500,000 to 1,000,000 eggs per growing season. Young of the year zebra mussels become sexually mature their first growing season. Unfortunately, 1% of 900 gazillion is still enough recruiting offspring to choke our lakes. The zebra mussels have developed a very successful reproductive stategy.
It was originally thought that the zebra mussels wouldn't do well in the warmer waters of the United States. As the zebra mussel spread marched south from the Great Lakes that theory was quickly proven wrong. The zebra mussels have been able to adapt to the warmer water temperatures and still thrive. At one time, the zebra mussels at Winfield City Lake were found to be the most thermally tolerant population in the database. As you mentioned, new information is gained each day as scientists continue to study the zebra mussel. Hopefully the solution is found soon but until then preventing the spread to additional waters is our best weapon.
While many species of Kansas fish can and do consume zebra mussels they can't consume enough to impact the zebra mussel population. Blue cats do feed upon zebra mussels during the summer months but they can't keep up with the overpowering reproduction of the mussels. Stocking blue catfish to control zebra mussels could be described as taking a fly swatter to a feed lot--you're going to kill a lot of flies but you aren't going to impact the population. When I originally stocked blues in El Dorado I hoped to create a positive (blue cat population) from a negative (zebra mussel infestation) as the blues fed upon the zebra mussels. It appears to be working as blue cats are now naturally recruiting in the lake, but as expected no decrease in zebra mussel density has occurred since the introduction of the blue cats. Common carp and freshwater drum feed heavily upon zebra mussels as well. Channel catfish utilize them to a lesser extent. I see blue cats on a regular basis at El Dorado that are packed full of zebra mussels.
Here's a picture of one of the zebra mussel samplers at El Dorado Reservoir from July 2004 and again in August 2005 which shows how quickly zebra mussels can colonize a lake. Notice how the majority of the zebra mussels in the left side of the picture are either in the inside or underneath side of the PVC sampler. These darker, hidden areas are the 'prime' areas for zebra mussels but as these 'prime' areas are taken other zebra mussels will occupy the poorer locations which results in complete coverage. In low density populations, zebra mussels will most always be found on the underneath side of rocks or other substrates instead of on the top where they would be more noticeable to humans. When searching for zebra mussels it is best to flip rocks and look at these 'prime' areas. This reclusive nature of young, low density populations is likely responsible for delayed discovery of new infestations.