October 2015 Newsletter

A Closer Look #154

AWRI Hires New Postdoctoral Researcher

Dirk Koopmans

AWRI has hired a new Postdoctoral Research Associate, Dr. Dirk Koopmans, who joins the Biddanda lab to collaborate on the Muskegon Lake Observatory, an array of water quality sensors powered by a solar-panel-equipped buoy on Muskegon Lake. Dirk completed his Ph.D. at the University of Virginia in research on groundwater-surface water interactions and stream ecosystem metabolism. He then served as a researcher at the University of Wisconsin – Milwaukee, School of Freshwater Sciences where he studied oxygen depletion in bottom waters of Green Bay. He is now excited to have the opportunity to contribute to exploring similar phenomena on this side of Lake Michigan – in Muskegon Lake.

For the past five years, the Observatory has tracked the summer-time ups and downs in dissolved oxygen concentrations in Muskegon Lake. For much of the late summer and early fall bottom water oxygen concentrations have been low enough that fish need to move elsewhere to survive. Dirk will be working with his postdoctoral advisor, Bopi Biddanda, M.S. student Anthony Weinke, and other colleagues in AWRI to study the causes and consequences of this phenomenon. Findings so far suggest that episodic high wind events, which mix the lake, as well as occasional inflow of large volumes of cold, dense, oxygen-rich Lake Michigan water following coastal upwelling events, help restore healthy oxygen concentrations in Muskegon Lake. The inner workings of this estuary are dynamic and may serve as a model for similar coastal lake ecosystems around the Great Lakes.