Grass carp for farm ponds

Asked March 8, 2018, 4:18 PM EST

Good afternoon. I have 24 different ponds throughout my property but was beginning to think about stocking grass carp in 2 of them to help control vegetation. The first one is a pond that is used as a "bait pond" as I call it to raise small fish to use in recreational fishing around home on several lakes and rivers. The second pond is just one that is used as a water source for a pasture of feeder cattle.

My 2 questions are if I do decide to stock grass carp in my ponds, what is the ratio to configure the amount of fish I put in the body of water? Is it based of of Square feet or another measuring method?

And what is the lifespan of these fish? How often would I need to restock them in my ponds?

Thank you for taking the time to look at my question.

Oklahoma County Oklahoma

1 Response

Before jumping to use grass carp or any other aquatic plant managment tool, it is best to explore the reasons behind pond plant overabundance. The most common underlying causes are shallowness and excess nutrients from watershed runoff. Typically the underlying cause needs to be corrected before lasting results can be acheived.

There is much to consider about grass carp. In some cases they worsen conditions by removing all pond plants causing problems like wave erosion of shorelines and muddiness or harm to fishing quality by eliminating submerged plants which provide shelter for smaller frish from predators and insects for fish to eat. Small grass carp are readily eaten by bass. Grass carp do not work on all pond plants, especially tough, fibrous ones. Grass carp readily escape across spillways during overflows. The fact sheets available at go into more detail.

Recommended stocking rate is 10 grass carp per vegetated acre. So, for a one acre pond that is 50% covered by aquatic plants, five grass carp would be needed. One acre is 43,560 square feet.

Excpected lifespan is around 8 - 10 years. That would also be the expected restocking interval. Effects of grass carp on plant beds are usually not seen until a couple of years pass and the fish are large enough to be consuming enough plant material.

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