Publication Date:
2012-11-22
Description:
We evaluated the response of the zooplankton community Saginaw Bay, Lake Huron to the disappearance of the planktivore alewife Alosa pseudoharengus using data collected in 1991–1996 (pre alewife decline) and 2009–2010 (post alewife decline). Bosmina longirostris , Diaptomidae, Cyclops , and Daphnia galeata contributed greatly to the separation of the two time periods with Diaptomidae and D. galeata increasing and Cyclops and B. longirostris decreasing, although B. longirostris remained the dominant species. Peak densities of zooplankton occurred in early summer (June) in the 1990s and in early fall (October) in 2009–2010. For the analysis of environmental variables on a bay-wide, annual basis, abundance of alewife, age-0 yellow perch Perca flavescens and Bythotrephes captured much of the variation in annual zooplankton community structure. Abundances of Bythotrephes and age-0 yellow perch were both higher in 2009–2010 than in 1991–1996. Some changes such as increasing proportions of calanoid copepods reflect a more oligotrophic community and are potentially indicative of resource-driven changes rather than direct or indirect impacts of the alewife disappearance. Content Type Journal Article Pages 1-12 DOI 10.1007/s10452-012-9420-1 Authors Steven A. Pothoven, National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory, 1431 Beach Street, Muskegon, MI 49441, USA Tomas O. Höök, Department of Forestry and Natural Resources, Purdue University, 195 Marstellar St., West Lafayette, IN 47907, USA Thomas F. Nalepa, National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory, 4840 S. State Road, Ann Arbor, MI 48108, USA Michael V. Thomas, Michigan Department of Natural Resources, Lake St. Clair Fisheries Research Station, 33135 South River Road Harrison Twp., Mt. Clemens, MI 48045, USA Julianne Dyble, National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory, 4840 S. State Road, Ann Arbor, MI 48108, USA Journal Aquatic Ecology Online ISSN 1573-5125 Print ISSN 1386-2588
Print ISSN:
1386-2588
Electronic ISSN:
1573-5125
Topics:
Biology
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