District Health Department #10 (DHD#10) in cooperation with the Michigan Department of Environment Great Lakes and Energy (EGLE), has confirmed that a reported algae bloom at Bass Lake is a harmful algae bloom (HAB). Bass Lake is located in Mason and Oceana counties and is part of Summit Township.
A HAB has been confirmed at Bass Lake on Monday, August 17, 2026. DHD#10 will continue to monitor the HAB and will provide updates to the public when available. Algae blooms can form when there are high nutrient levels within bodies of water along with warm temperatures. Signs will be posted at the public access site of the lake to notify individuals to avoid contact with the water in that area as a precautionary measure.
Contact with algae blooms can cause minor illness in humans but can be fatal to pets. Therefore, it is also recommended that people keep their pets out of water that shows any signs of algae blooms.
If you think that you or your pet has been exposed to algae blooms, take the following precautions:
• Immediately remove yourself and/or your pet from the area.
• Take a shower and thoroughly rinse off pets with clean, fresh water if they swam in an area with algae blooms to avoid potential toxic ingestion from licking between paws or affected areas.
• Seek medical treatment for yourself and/or veterinary treatment for your pet as soon as possible if you think you or your pet may have been exposed to or ingested algal toxins.
