Interesting subject. Here is a link to a comprehensive study on the topic of carp and their impact upon lakes and native fish species.

http://www.hort.agri.umn.edu/h5015/00papers/baldry.htm

Short version is that carp are bad for a fishery because they uproot plant life and decrease water clarity. Longer version is that in 100 years of trying, noone has come up with a way to control them yet. Alot of the research was very interesting. Grass carp are used in certain areas to control aquatic growth, however they suggest only using sterile carp for it because carp can grow so large and breed so quickly. It would appear that the only places that had successful carp population control were areas where carp are regularly targeted for harvest by fisherman. (Europe and parts of Asia)
It would appear the single most effective thing we can do as fisherman, is fish. For carp. Not very glamorous but they do put up an awesome fight. I could not find any recent history of any efforts being made in California for control of carp populations. I suspect the danger posed by carp to our fisheries are of a much lower priority than the lowered water levels and increased toxin levels. Maybe we can put all the comorants into a 12 step program to transistion their diet from trout and bass to carp.
And finally, no hidden agendas and motivations, just not going to make a public statement until some research has been done. That is part of my getting a paycheck from a library is all about right? Freedom to learn and decide.