Providing underwater structure can improve fish populations
What’s doable when it is cold outside is improving underwater habitat for forage and sport fish in ponds and small lakes. The Missouri Department of Conservation suggests adding underwater structures to boost sport fish such as largemouth bass and the fathead minnows they feed on. Completing projects will now have them ready for spring when fish spawn and summer when anglers like to catch fish.
“Structures are good if you want to attract fish to certain areas, like near docks or in a place within casting distance of shore,” said St. Joesph MDC fisheries management biologist Tory Mason. “Another use is providing spawning habitat.”
Structure can be a tree or group of trees, wooden shipping pallets, PVC pipe arrangements, or benches made from concrete blocks and boards. As a fish attractant for ice fishing, the structure should be placed in the deepest part of the pond, Mason said. In spring and summer fish will usually prefer more shallow water habitats, especially when spawning. Fish prefer spawning and resting sites offering them shelter from disturbance or predators.
“Fish feel more comfortable being near something,” Mason said.
Fathead minnows can be an important food to help fish such as largemouth bass grow large. But just because they’re small doesn’t mean they don’t have complexities, like privacy for spawning. Fathead minnow females lay eggs, males fertilize and guard them. The males will chase away other males and females from the eggs.
“They all want their own little space, their own territory,” Mason said. “As long as they can’t see one another they’re okay. Otherwise, they will just harass each other.”
Shipping pallets stacked in shallow water or placed atop concrete blocks provides spawning habitat for minnows.
Sport fish relate to structure, too, for escape cover, shade and resting spots. Trees are an inexpensive way to provide habitat. But being selective about which trees is helpful. Hardwood or red cedar trees are best because they can last a long time under water before rotting away. Oak, hickory, Osage orange, and locust all work well. The down-side is they are a place to hang up lures and bait. The upside is they attract fish for years. Discarded Christmas pine or fir trees have often been sunk in ponds and lakes as habitat. They provide some cover for a year or so but rot away quickly.
Some pond owners attach boards to upright concrete blocks to make bench-like structures and place them under water near shore. Bass like to spawn under them. Channel catfish spawn in cavities, so a large PVC pipe with a 10-inch opening provides them a spawning cavity.
During a hard winter freeze when the ice is thick structures can be hauled out onto the ice and allowed to drop to the bottom when the ice melts. Trees or artificial structures will need to be weighted down with concrete blocks or stone to sink and stay on the bottom.
For more information about adding structure for fish in ponds, visit https://short.mdc.mo.gov/Z57. To discuss pond habitat with MDC’s Tory Mason, call (816) 271-3111, ext. 1432.