MILC 90 Min Session 18 Algal Blooms and HABs

• 0:00: Harmful algal blooms in Michigan's recreational waters: Aaron Parker, Michigan Department of Environment, Great Lakes, and Energy
• 33:10: HABs events in Muskegon Lake: Dr. Richard Rediske, Annis Water Resources Institute
• 53:00: Adverse Impacts of HABs: Dr. Susan Peters, Michigan Department of Health and Human Services

The Michigan Departments of Environment, Great Lakes, and Energy (EGLE) and Human Health and Services (DHHS) have been tracking cyanobacteria blooms in Michigan inland waterways since 2016. Most blooms that EGLE and DHHS become aware of are reported by citizens. When possible, samples are collected by trained staff throughout the state and analyzed for cyanotoxins. Results are then relayed to local health departments to communicate health advisories to the public. Since monitoring began, the number of waterbodies with confirmed cyanobacteria blooms has increased. Regression analysis of county central latitudes and number of blooms in the respective counties revealed a significant inverse relationship (R2 = 0.25, p < 0.001) confirming our observations that most blooms occur in the southern half of the Lower Peninsula. Instances of the less common cyanotoxins anatoxin-a and cylindrospermopsin began in the southern part of the state and have been expanding further north. Over half of the lake systems that have had cyanobacteria blooms have either been reservoir systems or natural lakes with dams at their outlets. However, only about 11% of the lakes in Michigan that are >5 acres in size are reservoirs or natural lakes with dams, indicating that these waterbody types are over-represented amongst lakes with confirmed cyanobacteria blooms. Reservoir systems are significantly shallower (Analysis of Variance [ANOVA] F = 5.25, p < 0.001) and have higher shoreline development factors (ANOVA F = 7.87, p < 0.001) than both natural lakes and natural lakes with dams.

Find more presentations from the 2022 Michigan Inland Lakes Convention here.