Maintaining balance in the food chain may be enhanced by habitat or structures where smaller fish can survive safe from predation. Pond fish always try to hide when danger threatens. They hide by moving into deeper water, or taking refuge behind a stump, rock or plant. Fish communities exist without physical structure but they are certain to concentrate in and around structure when it is present. Additionally, various fish species require specific bottom conditions or shelter for reproduction. Many manmade lakes can benefit from the addition of fish shelters. There are several items that may be placed on the lake bottom to create a safe environment. These include discarded Christmas trees, unwanted rocks and wood pallets wrapped in ? inch galvanized chicken wire. See the following sketches for other productive shelter ideas.
Catfish Spawning Boxes
Catfish are particular about their spawning environment. You can encourage them with a simple spawning box constructed of PVC pipe with square end caps. The square caps prevent the pipe from rolling and offer stability when it is on the lake bottom. The boxes are constructed of 12-16 inch diameter PVC pipe. Using aluminum plate, plastic sheet material, or wood, cut square end caps two inches larger than the pipe diameter. Cut a 6-inch hole in the plate on one end and attach it to the pipe using L- brackets. It is best to use stainless or non-corrosive materials for the brackets and screws. Fix a solid end cap to the opposite end to provide a single 6-inch entry/exit opening. Tie a cord around the pipe so you can remove it from the water if you get too much spawn.
Minnow and Small fish Habitat
Here is a simple, inexpensive way to provide a safe haven for fatheads and other small minnows. Cover discarded wood pallets with half-inch galvanized chicken wire. Sink the pallets in the lake using concrete blocks if additional ballast is required.
Pyramid Fish Habitat (For Medium Size Fish)
Fish habitat provides a safe space for small to medium-sized fish to hide, congregate and grow. This is important in water containing predator species like bass. In lakes where weed growth is being managed and natural habitat is minimal, the addition of pyramid habitat is a good substitute and assists in maintaining a balanced fish population. Pyramid habitat may be constructed using 16-18 inch sections of 6-8 inch corrugated or straight pipe banded together. Cover both ends with 1-inch plastic mesh or galvanized chicken wire and sink the assembly in 4-8 feet of water.