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Facts about the Triploid White Amur
(Grass Carp)

Grass Carp have been used over 700 years for food and to control aquatic weeds in China.  Its popularity has spread over many parts of the world.  This fish is not the common carp normally found in the United States.  It is the largest species in the minnow family.  Growing to approximately 35 pounds and consuming 3 times it’s own body weight per day in vegetation, this fish will not muddy up your water like the common carp and the flesh has a desirable taste.

Stocking rates for Grass Carp vary depending on the amount and kind of vegetation in the pond.  For ponds with the surface covered by more than 60 percent vegetation, stock them at 20 fish per acre, but reduce the rate to 10 fish per acre for ponds with 40 to 60 percent vegetative cover, and to five fish per acre for ponds with 20 to 40 percent vegetative cover.  Grass carp are not recommended for less severe problems.  More fish can be added if these stocking rates do not provide adequate control.  Wait at least three years after your initial stocking before deciding if you need more fish.

Grass carp may not be effective for controlling milfoil, water meal, filamentous algae, or pond lilies.

Leafy, rooted aquatic plants, such as naiad, pond weed and coontail, are the preferred food of white amur.  Lacking these they may consume floating duckweed, green algae, and even cattails.

Although cultured in Asia as a source of food, in the U.S., the primary interest in the white amur is to control aquatic vegetation, especially where it is desirable to avoid the use of chemical herbicides.  This may be the affordable answer to many serious weed problems without the use of expensive and toxic chemicals.

To accommodate an increasing demand for white amur, yet to avoid the possibility of their becoming established in systems where they are not wanted, a sterile, triploid form was developed.  Many states including Ohio have legalized the sale and use of triploid white amur for vegetation control providing proper receipts, authorization and records are kept.

There are a couple of things to remember about grass carp.  First, pond owners should not expect them to solve a vegetation problem overnight.  The fish will eat more as they grow older and bigger, and it may take them a year or two to reduce plant growth.  Second, it’s much easier to put grass carp into a pond than it is to remove them.  Grass carp should not be stocked in a new pond until there is a vegetation problem, and applications should start at low initial stocking rates and be increased later as necessary.  Third, if largemouth bass or other large predators are present in the pond to be stocked, the white amur should not be smaller than 8 to 10 inches in length.

Finally, white amur have a natural tendency to migrate out of ponds /lakes toward moving water.  Ponds owners who have inflows or outflows to their ponds (including high water spillways) may wish to install barriers prior to stocking the triploid white amur to prevent their escape.  Barriers can be easily constructed to keep grass carp ten inches and larger in ponds, but caution should be exercised.  Sacrificing the costs of a few fish is far cheaper than jeopardizing the safety of your pond dam.  Information on the construction of barriers is available from the Division of Wildlife (District 5) (937) 372-9261 or Butler Soil & Water Conservation District (513) 887-3720.

The following is a list of dealers who are permitted to import and sell USFWS certified Triploid White Amur (Grass Carp) in Southwestern Ohio: