NEBRASKAland

NEBRASKAland December 2017

NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.

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54 NEBRASKAland • DECEMBER 2017 W ith the construction side of a major project to remove and keep common carp out of the Sandhills lakes on the Valentine National Refuge complete, the next phase – actually eliminating the carp – will begin in late 2018 with the renovation of three lakes, including Pelican Lake. Native to Europe, bottom-feeding carp stir up sediments and cloud the water, hampering the growth of the aquatic vegetation that is the base of the food web, and the growth and productivity of sight-feeding gamefish, including the bluegill, yellow perch, black crappie, largemouth bass and northern pike that thrive in Sandhills lakes. Carp found their way onto the refuge in the 1930s when a ditch was dug from Gordon Creek northwest of the refuge to alleviate low water. Nine of the 36 lakes on the 71,516-acre refuge in Cherry County are open to fishing. In the 1970s and 1980s, rotenone, a chemical that kills gill-breathing organisms, was used to remove carp from the seven fishing lakes where they were present. The waters quickly cleared and the refuge developed into a world-class fishery renowned for producing trophy panfish. The nature of Sandhills lakes, with cattail-lined shores and adjacent marshes, however, made it difficult to kill all of the carp in a lake, and the ditches and creeks connecting the lakes allowed carp to find their way back in. That was most recently seen in Hackberry Lake, where carp reappeared soon after a 2004 renovation. Duck and Rice lakes were carp-free prior to these early renovations and remain that way. West Long Lake has remained carp-free since it was renovated in 1976. All three continue to produce quality panfish and largemouth bass. Biologists have found that when carp populations reach a certain level, the body condition of gamefish begins to decline. In the other fishing lakes – Watts, Pelican, Hackberry, Dewey, Clear and Willow lakes – carp levels were at or well above those levels when work began. Biologists and engineers have been working together on the current project, a cooperative effort between the Nebraska Game and Parks Commission, its Aquatic Habitat Program and the U.S. Fish and Wildlife Service (FWS), to find a way to keep carp out of the refuge lakes once they are removed. New or redesigned water control structures on the outlets below each lake will keep fish from moving upstream into a lake, even during periods of high water, and to allow FWS personnel to manage water levels. Channels were dredged between the outlets' main lake bodies to insure maximum drawdown prior to a renovation. The key piece to this puzzle is a barrier constructed on the stream below Willow Lake, the last lake in the system, which will prevent carp from finding their way onto the refuge from private lakes to the northeast. Separated from the other lakes, Watts Lake was the test subject for the process. Work began there in 2014, and when it was renovated in 2015, managers were able to lower the lake 3 feet, drawing the water out of all of the vegetation to all but insure a complete kill of carp and cutting chemical costs in half. Growth rates of the bass, bluegills, perch and crappie stocked following the work have been excellent, and anglers began pulling keeper-sized fish from the lake this year. Biologists expect the same at the rest of the refuge lakes. "They were phenomenal fisheries in the 1970s and 80s, and we think this work will get them back to that potential," Commission Fisheries Biologist Zac Brashears said. A top-down approach to renovation is tentatively set to begin in August or September of 2018 with Pelican, School and Whitewater lakes. The latter two lakes aren't open to fishing, but because of their connections to those that are and the presence of carp, they are being renovated. Work will continue in 2019 at Hackberry Lake; 2020 at Dewey Lake, and wrap up in 2021 with Clear; McKeel, another non- Valentine NWR Update By Eric Fowler Renovations planned for many Sandhills lakes. Fisheries managers believe with carp removed, refuge lakes will again be capable of producing trophy bluegills like this 11-incher sampled on Duck Lake. PHOTO BY ZAC BRASHEARS

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