Author
FENECH, AMY - UAPB | |
RACEY, C. - UAPB | |
Radomski, Andrew | |
LOCHMANN, STEVE - UAPB |
Submitted to: Southeastern Association of Fish and Wildlife Agencies Conference
Publication Type: Proceedings Publication Acceptance Date: 10/19/2005 Publication Date: 12/1/2006 Citation: Fenech, A.S., Racey, C.L., Radomski, A.A., Lochmann, S. 2006. Cormorants predation of largemouth bass in Chicot, Arkansas. Southeastern Association of Fish and Wildlife Agencies Conference. p.303-312. Interpretive Summary: Fisheries managers and anglers are concerned about the effects that increasing over-wintering populations of fish-eating Double-crested Cormorants have on game fish populations in the southeastern United States. We estimated the mortality of crappie and largemouth bass populations due to predation by cormorants in an oxbow lake of southeastern Arkansas. Diet overlap of cormorants and largemouth bass was evaluated for fall, winter, spring, and all seasons combined in Lake Chicot. We calculated that cormorants consumed 47 - 2754 crappies and 59 - 3122 largemouth bass from a 5000-acre oxbow lake in 2001. Cormorants consumed an estimated 0.001% to 0.34% of the crappie population per year when using fish-killed data to estimate population abundance or 0.01% to 1.01% of the population when using creel data. Cormorants consumed 0.13% to 13.83% of the largemouth bass population when using fish-killed data and 0.02% to 4.64% when using creel data to estimate population abundance. The number of sport fish in the population and the number of cormorants feeding on Lake Chicot per day were the most important factors in determining loss rate (%) due to cormorants. Diet overlap was biologically significant (greater than 60%) only in the fall. Over-wintering cormorants had little negative effect on largemouth bass and crappie populations in Lake Chicot. Technical Abstract: Fisheries managers and anglers are concerned about the effects that increasing over-wintering populations of piscivorous Double-crested Cormorants Phalacrocorax auritus have on game fish populations in the southeastern United States. We estimated the mortality of crappie Pomoxis spp. and largemouth bass Micropterus salmoides populations due to predation by cormorants in an oxbow lake of southeastern Arkansas. Diet overlap of cormorants and largemouth bass was evaluated for fall, winter, spring, and all seasons combined in Lake Chicot. We calculated that cormorants consumed 47 - 2754 crappies and 59 - 3122 largemouth bass from a 2024-ha oxbow lake in 2001. Cormorants consumed an estimated 0.001% to 0.34% of the crappie population per year when using rotenone data to estimate population abundance or 0.01% to 1.01% of the population when using creel data. Cormorants consumed 0.13% to 13.83% of the largemouth bass population when using rotenone data and 0.02% to 4.64% when using creel data to estimate population abundance. The number of sport fish in the population and the number of cormorants feeding on Lake Chicot per day were the most important factors in determining loss rate (%) due to cormorants. Diet overlap was biologically significant (greater than 60%) only in the fall. Over-wintering cormorants had little negative effect on largemouth bass and crappie populations in Lake Chicot. |