****Ever since Asian carp were accidentally introduced into U.S. rivers in the 1970s, the invasive fish****
Invasive fish? If I remember correctly the European carp was introduced in the 1800s by the US government.
The Asian grass carp was introduced on purpose in the 1970s to clean up waterways and ponds clogged with moss.
Thats true. I know a man who paid top $$s for two of them to clean out his 'decorative' pond. It was a pretty fancy affair with lights and landscaping that became overgrown with grasses. The fish cleaned it up in one summer and kept it (returned it) to its intended beauty.
He brought them inside each winter to keep them from freezing up.