Grass Carp is on Michigan's Invasive Species watch list and is prohibited. They have large, crosshatched scales, can reach lengths of more than 5 feet and weigh over 80 lbs. Their eyes are level with their mouths and have shorter dorsal fins than goldfish or common carp.
They prefer quiet, shallow waters but are tolerant to low levels of salinity, so they may occasionally live in brackish water.
Grass carp feed on plants and are able to consume 90 lbs of food a day. They are only able to digest half of it and expel the rest. This contributes to dangerous algal blooms and eutrophic conditions which can kill native plants & animals.
Grass carp are also notorious for destroying weed beds which are used by native fish for spawning. They are also proficient at damaging wetland ecosystems and waterfowl habitats as they forage for food.