Grantee Research Project Results

Zooplankton Resource Quality Patterns Within Shallow Lakes

EPA Grant Number: FP916955
Title: Zooplankton Resource Quality Patterns Within Shallow Lakes
Investigators: Booker, Joshua
Institution: Michigan State University
EPA Project Officer: Packard, Benjamin H
Project Period: September 1, 2008 through August 31, 2010
RFA: STAR Graduate Fellowships (2008) RFA Text |  Recipients Lists
Research Category: Academic Fellowships

Objective:

Zooplankton grazing on phytoplankton is a primary mechanism by which the valuable clear-water state of shallow lakes is maintained. It is known that horizontally migrating zooplankton, such as Daphnia, graze on littoral resources while utilizing the macrophyte beds as a refuge from predators. What is not known, however, is the potential cost this grazing may have on Daphnia, as there are likely differences in phytoplankton quality and quantity between the littoral and pelagic environments due to the presence of macrophytes. My proposed research will be the first to specifically examine the horizontal distribution of Daphnia resources in multiple shallow lakes.

This project aims to describe the horizontal distribution of Daphnia resource quality within shallow lakes. I also seek to determine the impact macrophyte density has on phytoplankton quality, clarifying macrophyte-phytoplankton interactions.

Approach:

I will utilize lake surveys and field observations to determine the presence resource heterogeneity within lakes. Food quality for zooplankton will be assessed by analyzing seston samples for carbon, phosphorus, and fatty acid content. Both lab and in situ Daphnia cultures will also aid in assessing the quality of resources from the perspective of a keystone herbivore.

Expected Results:

I expect to find that macrophytes have a negative impact on the quality and quantity of resources for Daphnia, through competition for nutrients, shading, and allelopathic chemicals. This deleterious influence of macrophytes may result in a distribution of resources that increases in quantity and quality with increasing distance from shore. My results will have implications for research on horizontally migrating Daphnia and corresponding population dynamic models for these ecologically vital organisms. The findings of this project will add to our understanding of often overlooked shallow lake systems, and improve the ability of lake managers to protect and restore these important habitats.

Supplemental Keywords:

zooplankton, shallow lakes, phytoplankton, macrophytes, food quality,

Progress and Final Reports:

2009

Final