PINE BLUFF -- During the summer months, landowners and their families can enjoy the fun recreational benefits of having a farm pond, Scott Jones, small impoundment Extension specialist at the University of Arkansas at Pine Bluff, said in a news release.
During breaks from the summer fun, they can also take some steps to ensure the health of their ponds and fish populations.
Controlling aquatic weeds
The most frequent problem pond owners face in the summer is excessive aquatic vegetation, Jones said. Some weeds can grow so quickly that they could make it difficult to swim, fish or launch a boat.
"While plants are valuable to pond ecosystems, small ponds are especially vulnerable to excessive plant growth," he said. "Compared to larger ponds, small ponds have a higher ratio of shallow water to deep water. This can lead to substantial weed infestations."
Jones said the first step to managing a problem plant is to identify it. Handy DIY identification resources can be found at Texas A&M AgriLife Extension's "AquaPlant" webpage (https://aquaplant.tamu.edu/) and at the University of Florida Institute of Food and Agricultural Science's Center for Aquatic and Invasive Plants website (https://plants.ifas.ufl.edu/).
Once the plants are identified, refer to the publication MP556 -- Aquatic Vegetation Control in Arkansas for guidance on selecting the appropriate control and treatment options. This and many more helpful publications can be found by searching their name or number at the University of Arkansas Division of Agriculture Cooperative Extension Service publications webpage (https://www.uaex.edu/publications/). Contact your county Cooperative Extension office at any time for guidance.
"Fish harvest is another important part of pond management," Jones said. "Ponds and lakes can only support so many fish. Harvesting some fish helps keep the population below its maximum sustainable yield. This allows the remaining fish to grow larger more quickly."
Jones advises pond owners to keep the following information on fish harvest rates in mind:
• Most ponds in Arkansas can support 10-15 pounds of largemouth bass harvest and 40-50 pounds of bluegill harvest per acre per year.
• Since channel catfish tend to not reproduce effectively in typical ponds, harvest them as you please and restock at 50-100 adults per acre when catch rates get low.
• Crappie and other species are so variable and/or unpredictable that no general harvest rates are widely accepted.
"Ponds that are highly productive or fed daily can support more harvest," Jones said. "UAPB Extension fisheries specialists and Arkansas Game and Fish Commission fisheries biologists can provide guidance on fish assessment and management."
Fish feed can have a dramatic impact on the growth and maximum size of bluegill and channel catfish, Jones said. Other sport fish in fed ponds also tend to get larger and more abundant by feeding on the healthy bluegill population.
"Select floating feeds so you can monitor feed intake and fish activity," he said. "Feed only what the fish can eat within 10 minutes. Do not feed more than 15 pounds per acre per day to reduce waste and nutrient enrichment, which can lead to vegetation problems."
Jones reminds landowners they can purchase feeds that consist of 28-32% protein, but fish will often grow faster on more expensive feeds that contain 40% or more protein.
Fertilizing the pond
Fertilization is often beneficial for newly-built or renovated ponds, Jones said. But the practice becomes less important and potentially harmful as the pond gets older.
"In general, if you cannot see more than 36 inches into your pond's water you probably do not need fertilization," he said. "If your water is very clear, fertilization may be beneficial, but you should also have your water chemistry analyzed through your local University of Arkansas Cooperative Extension Service office to see if there are other issues preventing beneficial algae from growing."
Jones recommends landowners read the publication MP360 -- Farm Pond Management for Recreational Fishing for details on when and how to fertilize.
"Though fertilization is a commonly recommended strategy for producing bigger fish, it may do more harm than good," he said. "Much of the land in Arkansas is already fairly fertile, and runoff from agricultural land carries nutrients to streams, rivers, ponds and lakes that contribute to phytoplankton and zooplankton blooms. These organisms are the base of aquatic food chains, and higher fertility tends to allow for more abundant and larger fish."
When excessive nutrients accumulate in ponds, however, aquatic weeds become more likely. Blue-green algae (cyanobacteria) can also begin to outcompete green algae in these highly fertile ponds in the mid to late summer.
"The numerous blue-green algae species do not contribute to the food chain as well as green algae, and they can form nasty-looking, smelly and potentially harmful surface scums," Jones said. "Once these blooms have occurred, there is not much that can be safely done to reduce them in the short-term. The best solution is to prevent excessive nutrient accumulation by fertilizing only when necessary and feeding only as much as the fish can eat within about 10 minutes."
For more information on pond maintenance, email Jones at [email protected] or call 870-575-8185.