The effects of mechanically reducing northern pike density on the sport fish community of West Long Lake, Nebraska, USA |
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| Authors: | J C JOLLEY & D W WILLIS T J DEBATES and D D GRAHAM |
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| Institution: | Department of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, SD, USAMinnesota Department of Natural Resources, St. Paul, MN, USANebraska Game and Parks Commission, Lincoln, NE, USA |
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| Abstract: | Abstract Removal of piscivores may affect population size structure, abundance and growth rates of the remaining fish community. A total of 572 northern pike, Esox lucius L., was removed from 25-ha West Long Lake, Nebraska from 2003 to 2006. The northern pike population was reduced from 36 fish ha−1 and 22 kg ha−1 in 2002 to 20 fish ha−1 and 9 kg ha−1 in 2006. The northern pike population shifted to dominance by smaller individuals. Relative abundance increased for bluegill, Lepomis macrochirus Rafinesque, but remained similar between years for largemouth bass, Micropterus salmoides (Lacepède), and yellow perch, Perca flavescens (Mitchill). Bluegill and yellow perch size structure increased probably because of reduced predation by northern pike. The effects of reduced northern pike density on largemouth bass were less evident. The largemouth bass population may be returning to higher density with smaller size structure observed before pike were introduced. The sport fish community responded positively to the removal of northern pike in this small lake. |
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| Keywords: | bluegill fish removal largemouth bass northern pike predation yellow perch |
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