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Angela Defore publishes her Findings on Timing a Lake's Biological Productivity

Angela Defore publishes her Findings on Timing a Lake's Biological Productivity

Former graduate student Angie Defore published findings from her Master's thesis work titled “Year-round measures of planktonic metabolism reveal net autotrophy in surface waters of a Great Lakes estuary” in the September issue of the journal Aquatic Microbial Ecology.  Co-authors include graduate student Anthony Weinke, undergraduate student Morgan Lindback, and thesis advisor Bopi Biddanda.

In her paper, Angie reports that net production dominates during the spring, summer, and fall seasons, whereas net respiration is dominant only during the winter months.  This results in net annual autotrophy (i.e., surplus production) in the surface waters of Muskegon Lake estuary.  Her findings also shed light on a seriously understudied component of the annual cycle of lakes: the key role of winter months in nutrient regeneration that subsequently fuel spring production.  She identifies several factors – in-lake regeneration of nutrients during winter, spring-time nutrient loading from the Muskegon River watershed (2nd largest in Michigan), increased summer-time sunlight availability, and favorable residence time (2-4 weeks) that enable optimal retention of resources and completion of plankton and fish life cycles.  All these factors converge to make this estuary a zone of net annual primary productivity in the watershed, supporting one of the most productive fisheries in the state. 

Open access to the article is at:

Angie is currently working as a Water Pollution Control Analyst for the Village of Rantoul, Illinois.

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