Grass Carp feed on aquatic plants but can also consume detritus, insects, small fish, earthworms and other invertebrates in the absence of aquatic vegetation. This species can consume up to 40 percent of their body weight per day. By eating such huge quantities of plant biomass, they can significantly alter the composition of habitat by reducing food sources, shelter and spawning areas for native fish. Also, because they can only digest about half of the plant material that they consume each day, the remaining material is expelled into the water, enriching it with nutrients which promotes algal blooms.