COLUMBIA, Mo. – For people who hope to wet their lines in farm ponds next spring, autumn is the time to make their ponds fish-friendly, said a wildlife and fisheries specialist.
“Most landowners have some sort of goal for their ponds,” Robert Pierce said. “If fishing is one of them, there are some management considerations that can be acted on right now. You can improve your pond for next year.”
Drain advantage. Pierce said ponds with drains have distinct management advantages.
In deeper ponds, water levels can be drawn down 2 or 3 feet in late fall and maintained at that level throughout the winter. As ponds silt in, the area near the shore becomes shallower.
“Fall draw-down helps control aquatic weeds,” he said. “In fact, now’s a good time to deepen the pond edges. With deeper edges, you have less chance for vegetation problems to occur next spring. When you’re bank fishing, that can be a real problem.”
It’s also an ideal time to sample soils in the pond watershed, “just as you’d sample soils for a crop,” Pierce said.
By sampling the mud from the pond bottom, “you can determine whether you’ve got acidic conditions, which tie up nutrients.”
Ponds with high acidity can be improved by the addition of agricultural limestone.
Take mud samples from several locations in the pond, mix them evenly and spread the sample out to dry.
Send off the combined sample for analysis to a soil testing lab where tests will be run to determine whether lime should be applied.
One lab is at the University of Missouri and can be reached at 573-882-0623.
Testing emphasis. Pierce emphasized the importance of testing before adding lime or taking other such measures.
“No two ponds are alike, even when they’re on the same property,” he said.
“Think of a pond as a complex ecosystem that supports both predators like largemouth bass and prey species like bluegill sunfish,” he said. “Low water levels in the fall tend to concentrate fish, increasing forage availability for bass. Bass growth is often improved, and sunfish populations are reduced during this time of year.”
Autumn is also time to evaluate pond-stocking needs and to identify locations where fish shelters and structures such as Christmas trees could be added to enhance fish habitat in the pond, he said.
A common cause of fall fish-kills is pond “turnover,” he said.
During the summer, the warmer water is usually on the surface, and the cooler water, which has less oxygen, is on the bottom.
“If the upper layer cools suddenly and mixes with the lower, stagnant layer, then the resulting mixture might not contain enough oxygen to support fish,” he said.
“When you have cool autumn rains and strong winds, you can have rapid surface cooling,” Pierce said. “There’s more mixing and greater potential for oxygen depletion to occur.”
Ponds where there are annual low-oxygen fish kills can benefit from aeration.
Supplemental aeration is effective at one horsepower of electric aeration per surface acre of water, he said.
“If a turnover occurs, you might need additional aeration capacity,” he said.
“Think of a pond as a garden or an orchard,” he said. “To be productive, it must be properly laid out, fertilized, stocked, weeded, harvested and protected.”
