14 DAY TRIAL // A team of experts was recently awarded a research grant to investigate the level of hypoxia in Lake Michigan. Land use and climate change are taking their toll on the important lake, and experts from a US collaboration of scientists are scheduled to begin investigating the extent of this influence.
The group will look into the causes and effects of hypoxia (lack of oxygen) in an area of Lake Michigan called Green Bay. The work will be conducted by experts at the University of Wisconsin system (Milwaukee, Green Bay and Madison), the Green Bay Metropolitan Sewerage District, and the Wisconsin Department of Natural Resources.
Funds for the research initiative came from the US National Oceanic and Atmospheric Administration's (NOAA) Coastal Hypoxia Research Program. The four-year study will cost an estimated $1.36 million, of which some $348,000 have already been awarded for this year.
Green Bay has been affected by sustained oxygen deprivation for many decades, but experts are currently worried that the situation may escalate beyond control. They say that conditions are ripped at this point to allow for the development of dead zones, areas where microbes use up all the oxygen.
Oceans, seas and lakes can be equally affected by dead zones. In these regions, no complex organisms can survive, as most creatures need oxygen to breathe. In addition to such structures, fish kills may become more frequent and extensive as well. The research team is to check whether global warming plays a role in this.
Hypoxia can occur naturally, but it takes a fairly uncommon combination of events to trigger such an event. Rather, most often, it appears due to human influence. Runoff chemicals that make it into lakes, seas and oceans tend to accumulate, fostering the growth of oxygen-consuming microorganisms.
Pollution from agriculture is the main culprit triggering artificial hypoxia in the waters of Lake Michigan. The process also stimulates the growth of algae, which bloom and deplete oxygen levels even further. The blooms also block out sunlight in the process, so photosynthesis below a certain depth becomes impossible as well.
One-third of the watershed of Lake Michigan flows into Green Bay, which is why they are the target of the new investigation. The most important aspects the team will study will include watershed sources of nutrients, lake water stratification, and summertime wind conditions.
Data collected from these analyses will help scientists produce a new computer model, that will be capable of predicting the evolution of hypoxia and dead zones in the Bay. This could in turn inform authorities in their conservation efforts.
“These results will help us identify acceptable limits for nutrient levels in the water so we can begin to reduce hypoxia in Green Bay,” says Wisconsin department of natural resources expert Nicole Clayton.
“This project is an excellent example of NOAA’s efforts to provide actionable information to managers for ecosystem based management,” adds the director of the director of the NOAA Center for Sponsored Coastal Ocean Research, Robert Magnien, PhD.
“The complexity of linking multiple processes in the watershed with those in Great Lakes and coastal waters demand new state-of-the art ecological forecasting tools that also incorporate climate change,” he concludes.