Nebraskaland

62 Nebraskaland • June 2023 MIXED BAG An innovative project to create artificial underwater habitat at Branched Oak Lake near Lincoln will benefit both fish and anglers. Fish like largemouth bass, crappies and bluegills love structure, especially submerged trees. As flood control reservoirs age, this type of habitat declines. This lost habitat can be replaced with cedar trees or artificial structures. Knowing this, Joe Petrzilka, a Lincoln area angler, approached Nebraska Game and Parks Commission fisheries biologist Aaron Blank with an idea. He had found he could get partial spools of PVC pipe that was left over from projects such as running fiberoptic lines, and because these spools didn't have enough tubing for another project and were headed to the landfill, he could get them for free. Petrzilka wanted to build a few structures and place them in area lakes. Blank had a better idea: "If you can get PVC, lets put together a big event and get a bunch of anglers together and build 150 or 200 of these things. That will make the kind of impact we can study." So last October, with the PVC Petrzilka acquired, the 5-gallon buckets and concrete mix provided by Game and Parks, and the help of about 25 volunteers and staff, they built and sank 171 artificial "trees," taller ones for deep water and shorter versions for shallow water, in the two bays on the north side of Branched Oak State Recreation Area. Fisheries staff places cedar trees in the lakebed of reservoirs that are drained for Aquatic Habitat Program projects, tying them together with cable and adding cinder blocks as anchors that will keep them in place when the lake refills. But they also do several brushing projects each winter, dragging cedar trees onto the ice that are tied together and sink when the ice melts. The older reservoirs like those in the Salt Creek watershed that have suffered from siltation and where there is little woody habitat left are prime candidates for these projects. "Adding that in there gives a little bit of habitat for the fish and it concentrates fish for fishermen," Blank said. "And hopefully if you get enough of it added, you can start seeing some biological changes for our fish. If you can get aquatic insects and algae start to form on these structures, not only are you providing cover for the fish, you're also providing a food source." Blank had been wanting to do that type of project at Branched Oak for several years, but ice conditions hadn't been safe. "Of course, the year we get this artificial stuff in place we had good enough ice and were able to get another 200 cedar trees in there," Blank said. Blank said he prefers cedar trees because they are natural, provide a more complex structure and are free, with many growing in grasslands around reservoirs where they aren't wanted. But the artificial structures are easier to place from boats and don't snag anglers' lures. So when they cost as little as the ones placed in Branched Oak — about $5 each, a fraction of the hundreds commercially produced fish habitat can cost — there is a place for those as well. Blank said they are stockpiling more PVC that Petrzilka has acquired and will put together another event at an Omaha-area lake this summer. Using electrofishing and sonar, biologists will try to get an idea of the species and number of fish using the structures. He already knows fish are using them at Branched Oak. "I fished them a week later and I caught crappies off almost every one of those artificial structures," he said. Put some structure, any structure, in these older reservoirs, and fish will find it. That's good for the fish, and for anglers. BRANCHED OAK HABITAT By Eric Fowler Game and Parks biologist Aaron Blank and volunteer Sam Cowan load artificial fish habitat in a boat before placing it in Branched Oak Lake. ERIC FOWLER, NEBRASKALAND

• Cover