Blooms to Hypoxia: Muskegon Lake Observatory Tracks Ecosystem Changes in a Model Great Lakes Estuary

Session: 45. - Hypoxia: Causes, Impacts, and Management

Bopaiah Biddanda, Grand Valley State University, Annis Water Resources Inst., [email protected]
Anthony Weinke, GVSU AWRI, [email protected]
Scott Kendall, Grand Valley State Univ., [email protected]
Katie Knapp, Annis Water Resources Inst., [email protected]

Abstract

For the past 7 years, we have monitored Muskegon Lake – a model drowned river mouth Great Lakes estuary that is an Area of Concern with connectivity to the 2^nd largest watershed in Michigan and Lake Michigan.  Over the annual cycle, productivity is maximized in this estuarine "Goldilocks Zone" where longer residence times coincide with nutrient loading from the watershed.  Since spring 2011, using advanced observing technology, we have also been gathering high-resolution time-series data from meteorological and multi-depth water sensors through the Muskegon Lake Observatory (MLO; www.gvsu.edu/buoy).  MLO has revealed the intimate inner workings of Muskegon Lake such as how the estuary operates on a daily, monthly, seasonal, and yearly - basis.  For example, MLO has informed us about the annually recurring summer bottom water hypoxia and emergence of harmful cyanobacterial blooms (HABs) exposing daily and weekly oscillations in the severity of each.  With additional moorings and sensor strings deployed lake-wide during 2016-17, we now have evidence for substantial and episodic intrusion of upwelled cold and high-dissolved oxygen water from nearshore Lake Michigan into the bottom waters of the estuary during the summer-stratified period.  Open-access time-series data from MLO is advancing science, education, outreach and restoration activities.

1. Keyword
eutrophication

2. Keyword
oxygen

3. Keyword
observing systems

4. Additional Keyword
time-series measurements

5. Additional Keyword
annualyy recurring hypoxia

6. Additional Keyword
estuarine area of concern