Satellite Observed Water Quality Changes in the Great Lakes Due to Multiple Human-Induced Drivers

Session: 32. - Long-Term Monitoring: Achievements, Challenges, and Solutions

Robert Shuchman, Michigan Technological University, [email protected]
Karl Bosse, Michigan Tech Research Inst., [email protected]
Mike Sayers, Michigan Tech. Research Inst., [email protected]
Gary Fahnenstiel, Great Lakes Res Center/ Mich Tech Res Institute, Michigan Technological Univ, [email protected]
George Leshkevich, Great Lakes Env. Research Lab, NOAA, [email protected]

Abstract

Long time series of satellite data can be used to measure water quality parameters including chlorophyll, harmful algal blooms (HABs), photic zone and primary productivity on weekly, monthly and annual scales. The observed changes in these parameters over time are a direct result of the introduction of invasive species such as the Dreissena mussels as well as anthropogenic forcing and climate change. Time series of several water quality parameters have been generated based on a range of satellite sensors, starting with Landsat in the 1970s and continuing to present with MODIS and VIIRS. These time series show the effect mussels have had on the Great Lakes: increased water clarity due to declining algal populations, decreased primary productivity and chlorophyll concentrations, and an increase in submerged aquatic vegetation. Comparing water quality metrics in Lake Superior to the lower lakes is insightful because it is the largest and most northern lake and to date has not been affected by the invasive mussels and can thus be considered a control. In contrast, Lake Erie, the most southern and shallow of the lakes, is heavily influenced by agricultural practices (i.e., nutrient runoff) and climate change, which directly influence the increasing annual extent of HABs.

1. Keyword
remote sensing

2. Keyword
water quality

3. Keyword
invasive species

4. Additional Keyword
climate change