Well-designed ponds offer best habitat for fish

By KARI KRAMER | East Texas Edition

Matt Blaxton with Tommy's Fish Truck (top) hands over a bag of fish to a customer at the March 23 fish delivery at Northeast Texas Farmers Co-op in Sulphur Springs. Blaxton said this is one of their busiest times. -- Staff photo by Kramer

March 31, 2005 - Building and stocking a pond requires time and effort, but management is essential for pond ecosystems to thrive.

According to Texas Cooperative Extension, pond dams should have a compacted clay core. The pond bottom should be at least 30 percent clay. Adequate watershed areas are necessary to ensure that the pond receives enough run-off water to maintain healthy depth and movement.

Without enough watershed, the pond will become shallow. Unwanted plants tend to grow rapidly in shallow water. To prevent problems, TCE stresses that banks should have a radical slope and be at least two and a half feet in height.

Billy Higginbotham, Texas Cooperative Extension wildlife specialist, said before owners start "digging a hole" they should contact the Natural Resource Conservation Service. According to Higginbotham, the NRCS services all counties and has access to a vast array of information. The NRCS will look at soil maps to determine if the property has enough clay composition and adequate watershed, at no expense to the property owner.

"It would be absolutely foolish for landowners to not take advantage of that service," said Higginbotham.

Once a pond is filled, there is no waiting-period before the pond can be stocked, but there are a few more tasks that should be completed.

Before stocking, Higginbotham recommended owners take a few steps. "Most of our ponds are acid, and owners do well to get the water tested prior to stocking." The specialist said there are two types of tests needed. The first is a pH test. Higginbotham noted the pH should fall between 6.5 and 9. The second test examines the total alkalinity of the pond. Total alkalinity should be 20 parts per million. County Extension agents have the testing equipment needed. If test numbers are low, Higginbotham suggested agricultural lime be added.

Between the months of March and June, and October to December, catfish can be stocked. Catfish are a popular Texas pond choice because they require little space. Higginbotham said for ponds smaller than one acre, fish species that will accept a pelleted ration, such as catfish, are prime choices.

"For ponds smaller than one surface acre, we usually recommend one species," said Higginbotham.

Bass are a popular choice, but need larger water areas to survive. "We see a lot of problems with people stocking bass in ponds that are too small," Higginbotham said.

With bass, it is essential that bluegill are stocked as forage, but Higginbotham warned against stocking hybrid species of bluegill and sunfish. "When those hybrid species reproduce, the first generation, or F1 generation, is 95 percent male." The male to female ratio will not support adequate breeding and the feeder population will dwindle.

When stocking bass and bluegill, the owner must look ahead. If advanced bass and bluegill are stocked from March to the end of June, then beginning in mid-September, one-inch to three-inch bass should be stocked. If advanced bass and bluegill will be stocked from mid-September to December, then the smaller one-inch to three-inch bass should be stocked from May to June.

Pond size is extremely important and should be measured in surface area acres. Surface area in acres is the total when the square feet of the pond is divided by 43,560. According to Higginbotham, most people over-estimate their pond size, and add too many fish. "They stock two to three more times than recommendations call for."

When ponds are overstocked, the risk of oxygen-depletion rises. Oxygen depletion occurs more often in ponds with a smaller surface area. Deep water does not protect against oxygen depletion. Fish affected by oxygen depleted waters can often be seen at the water's surface. Harvesting excess fish can deter oxygen depletion.

Higginbotham advises against stocking any fish in the summer. "We try to avoid stocking fish during the hottest times of summer." He added that it can be difficult for fish trucks to keep fish healthy and water temperatures constant when the summer heat takes over.

For owners wishing to build, stock, or maintenance their pond, Texas Cooperative Extension agents, and the NRCS, have information available.