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Pyrethroid Insecticide Effects on Bluegill Sunfish (Lepomis Macrochirus) and the Impacts of Bluegill Predation on Invertebrates in Microcosms

Concurrent outdoor aquatic 1950 L microcosm and 0.04 ha mesocosm experiments with bluegill sunfish evaluated the ecological impact of cyfluthrin. Cyfluthrin effects were not observed on mesocosm bluegill; a slight decrease in growth was observed in the microcosm bluegill. Otolith weight to length relationships between bluegill size-classes from microcosms, local streams, and a fish hatchery revealed no differences. Our results indicated bluegill predation impacts were slight on benthic invertebrates. Extensive predation on emerging insects was observed. Microcosm bluegill impacts on zooplankton populations followed expected predation effects, resulting in larger populations of smaller taxa. Bluegill functioned as "keystone" predators for microcosm taxa and improved taxa richness for benthic colonizing invertebrates and zooplankton.

Identiferoai:union.ndltd.org:unt.edu/info:ark/67531/metadc500573
Date05 1900
CreatorsMorris, Rodney Gregg
ContributorsKennedy, James H., Beitinger, Thomas L., Dickson, Kenneth L.
PublisherUniversity of North Texas
Source SetsUniversity of North Texas
LanguageEnglish
Detected LanguageEnglish
TypeThesis or Dissertation
Formatvi, 101 leaves: ill., Text
RightsPublic, Morris, Rodney Gregg, Copyright, Copyright is held by the author, unless otherwise noted. All rights reserved.

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