, Volume 47, Issue 1, pp 1-12
Date: 18 Nov 2012

Changes in zooplankton community structure associated with the disappearance of invasive alewife in Saginaw Bay, Lake Huron

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

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.

Handling Editor: Piet Spaak