No, as to the carp in the river. The grass carp are supposed to be sterile so that they can't reproduce, but it's not 100% and they will eat anything green as the food source dwindles. I've seen them eat grass clippings off the surface of a pond, grass from the banks, debris that falls from trees into a lake in the Spring. They don't distinguish between oxygen producing weeds, indigenous and other types. I saw a 100 acre lake go from a great bass fishery to one I don't fish any more in 15 years, in fact my avatar is from there with a 5lb. SM. With no cover for the fry and with the influx of cormorants, it's not surprising the lake has really gone down hill.
Some grass carp pictures, 1st May 2014 on a Rapala: 2nd late Dec. 2015; 3rd in the Spring of 2011, these are the only ones that I have pics of. Besides catching them on different lures they were accidently snagged either early or late in the season.
