Biological Weed Control

Triploid Grass Carp

Triploid grass carp have been imported to the United States for the purpose of aquatic weed control.  Triploids are sterile, and each fish has been individually tested before final sale.  Grass carp are typically good at controlling submerged aquatic weeds like hydrilla, bushy pondweed, chara, and other soft-tissue species.  They are not a good choice for floating weeds, shoreline emergent weeds, or filamentous algae.

Stocking of grass carp requires a permit from the Texas Parks and Wildlife.  See the link to permit application to the right of this text. 

The TPWD currently allows the stocking of up to 10 grass carp per surface acre.  We stock the 12"+ size triploid grass carp, but smaller grass carp are available.

Mozambique Tilapia

Mozambique Tilapia are the only species of tilapia that are legal to stock in private impoundments in Texas without a permit.  These fish are a control option for several types of nuisance aquatic vegetation.  They will control the following species at adequate stocking rates:

  • Duckweed
  • Watermeal
  • Mosquito Fern
  • Filamentous Algae (Pond Scum)

The beauty of these fish is that they will essentially convert nuisance aquatic growth to fish weight and become part of the food chain for top-end predators like largemouth bass, catfish, etc.  

Triploid Grass Carp


Grass Carp Facts - TPWD Link
Grass Carp Information Sheet
Permit Application - TPWD link

Nicki Glazener with Trophy Tilapia