The silver carp is the one that tends to eat the phytoplankton, the algae, the smaller plankton. The bighead carp feed on the zooplankton. It's like a one-two punch. The first thing any native fish feeds on after it hatches is phytoplankton, and then it moves on to zooplankton. To me, this is the real impact. It is competing with every other species, not just a select species. It competes with every other species because it's competing for the food that every other species eats at some point in its life.
The issue with these bighead carp is they quickly outgrow the mouth size of any predator, so within the first year of life, this fish will be 30 centimetres long. They quickly outgrow the gape size of a northern pike or a muskellunge, so it will quickly have no predators.