Fish Stocking

Use of Triploid Grass Carp is one of several methods to control the hydrilla. Triploid grass carp are unique, olive-green, cigar-shaped fish often observed basking in the sunshine in shallow water as they soak up warm surface temperatures. What sets these fish apart from others is their intense appetite for a wide variety of underwater plant life. Often, plant problems in ponds and lakes are due to invasive, exotic species which have no natural enemies in Florida.

Grass carp come from Asia and have no natural enemies in Florida. The triploid “grass carp” is a sterile version of the white amur. It has been used in private and public Florida waters for the control of invasive aquatic plant species since 1972. Triploid grass carp are considered a natural method for controlling aquatic vegetation and macro-algae. They can live for many years, 20 years in some cases. Their ability to live long lives typically makes them significantly more cost effective than herbicides.

Grass carp usually take six months to a year to be effective in reducing problem vegetation, although they provide much longer-term control than other methods, often up to five years before restocking is necessary. When used in conjunction with herbicide treatments, control of problem vegetation can be achieved quickly, and fewer carp are required to maintain the desired level of vegetation.

In Florida, only triploid grass carp are allowed, and a permit is always required, even when stocking privately owned waters. Permits may be obtained by contacting the Florida Fish and Wildlife Conservation Commission (FWC).