Nearshore zooplankton communities of Lake Michigan and implications for invasibility by Asian carp

Recent, dramatic shifts have occurred within zooplankton community structure in Lake Michigan. Such changes could alter the ability of invasive species, such as Asian carp, to establish self-sustaining populations. Without knowledge of spatial characteristics of zooplankton communities, it is difficult to assess the potential for Asian carp establishment. We sought to better describe spatial heterogeneity of zooplankton community structure by surveying both large and small-bodied zooplankton at 25 nearshore embayment and open water locations around the lake for two years. With this geographically diverse dataset, we explored variation in zooplankton community structure and attempted to predict bighead and silver carp growth across large spatial scales. Our results indicate decreased total zooplankton biomass in nearshore open-water locations relative to embayments. Higher relative biomass of larger-bodied zooplankton was linked to embayments with higher primary production such as Green Bay and Michigan drowned river mouth lakes, while smaller-bodied zooplankton constituted the majority of biomass in open water and harbor locations with lower primary production. These biomass estimates, in turn, affected predicted Asian carp growth rates. Negative growth was predicted across most locations, with the exception of several drowned river mouth lakes along the Michigan coast and regions of Green Bay, Wisconsin. We suggest that recent declines in primary production related to establishment of quagga mussels throughout the basin and decreased nutrient loading in addition to increased prevalence of predatory zooplankton has led to a decrease in zooplankton biomass, shifted structure towards dominance by smaller-bodied taxa, and created a less hospitable environment for Asian carp survival through most nearshore regions of the lake.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Reed, Emily M

Contributors dc:contributor

• Czesny, Sergiusz J.
• Chick, John H.
• Larson, Eric R

• Lake Michigan
• Zooplankton
• Community structure
• Bioenergetics
• Risk assessment
• Bighead carp
• Silver carp

Statement dc:rights

• Copyright 2017 Emily Reed

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/98409

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/98409