Changes in the Lake Michigan food web following dreissenid mussel invasions: A synthesis

Journal of Great Lakes Research
By: , and 

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Abstract

Using various available time series for Lake Michigan, we examined changes in the Lake Michigan food web following the dreissenid mussel invasions and identified those changes most likely attributable to these invasions, thereby providing a synthesis. Expansion of the quagga mussel (Dreissena rostriformis bugensis) population into deeper waters, which began around 2004, appeared to have a substantial predatory effect on both phytoplankton abundance and primary production, with annual primary production in offshore (> 50 m deep) waters being reduced by about 35% by 2007. Primary production likely decreased in nearshore waters as well, primarily due to predatory effects exerted by the quagga mussel expansion. The drastic decline in Diporeia abundance in Lake Michigan during the 1990s and 2000s has been attributed to dreissenid mussel effects, but the exact mechanism by which the mussels were negatively affecting Diporeia abundance remains unknown. In turn, decreased Diporeia abundance was associated with reduced condition, growth, and/or energy density in alewife (Alosa pseudoharengus), lake whitefish (Coregonus clupeaformis), deepwater sculpin (Myoxocephalus thompsonii), and bloater (Coregonus hoyi). However, lake-wide biomass of salmonines, top predators in the food web, remained high during the 2000s, and consumption of alewives by salmonines actually increased between the 1980–1995 and 1996–2011 time periods. Moreover, abundance of the lake whitefish population, which supports Lake Michigan's most valuable commercial fishery, remained at historically high levels during the 2000s. Apparently, counterbalancing mechanisms operating within the complex Lake Michigan food web have enabled salmonines and lake whitefish to retain relatively high abundances despite reduced primary production.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Changes in the Lake Michigan food web following dreissenid mussel invasions: A synthesis
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2015.08.009
Volume 41
Issue Supplement 3
Year Published 2015
Language English
Publisher International Association for Great Lakes Research
Publisher location Toronto
Contributing office(s) Great Lakes Science Center
Description 15 p.
First page 217
Last page 231
Country United States
Other Geospatial Lake Michigan
Online Only (Y/N) N
Additional Online Files (Y/N) N