July 9, 2026

The Barry-Eaton District Health Department (BEDHD) is advising residents and visitors to use caution after a harmful algal bloom (HAB) was found at Gun Lake. 

Harmful algal blooms happen when blue-green algae (also called cyanobacteria) grow quickly in lakes and ponds. Some blooms can make toxins that are harmful to people and animals. You cannot tell if a bloom is harmful just by looking at it, so it is best to avoid any water that has visible algae. 

Do not swim, wade, water ski, or play in water that is discolored or has algae floating on the surface. Harmful algal blooms can make the water look bright green, blue-green, brown, or red. It may also look like spilled green paint, pea soup, or have thick mats of algae on the surface. 

Pets are at greater risk because they may drink lake water or lick algae off their fur after swimming. Keep pets away from water with algae, and do not let them drink lake water. If your pet gets into the water, rinse them off with clean water right away. Contact your veterinarian if they become sick. 

Symptoms of Exposure 
People can be exposed to harmful algae by touching the water, swallowing it, or breathing in water spray during activities like swimming or boating. 

Symptoms may include: 

• Skin rash or irritation 

• Red or irritated eyes 

• Irritated nose or throat 

• Stomach pain 

• Nausea, vomiting, or diarrhea 

• Headache 

• Fever 

• Coughing or trouble breathing after breathing in water spray 

Symptoms can start within a few hours or up to a few days after exposure. 

What to Do If You Have Been Exposed 
If you or your child come into contact with water that may have a harmful algal bloom: 

• Rinse off right away with clean, fresh water. 

• Wash swimsuits and towels before using them again. 

• Watch for symptoms over the next few days. 

If you become sick, contact your healthcare provider. Seek medical care right away if you have trouble breathing, severe vomiting, or other serious symptoms. 

If your pet was exposed, rinse them well with clean water and do not let them lick their fur until they have been washed. Contact your veterinarian right away if your pet has vomiting, diarrhea, weakness, trouble walking, excessive drooling, shaking, or seizures. 

Stay Safe Around the Water 
Before swimming or letting pets into the water: 

• Stay out of water that is bright green, blue-green, brown, or red. 

• Avoid water that looks like spilled paint, pea soup, or has floating mats of algae. 

• Follow any beach advisories or closures. 

• Shower with clean water after swimming in lakes or ponds. 

• Never drink untreated lake water. 

BEDHD will continue to monitor conditions in coordination with state partners and provide follow-up information as needed or until the harmful algal bloom has resolved. Harmful algal blooms can change quickly as weather and water conditions change. Always look at the water before swimming or letting pets enter. For the latest beach advisories and water quality information, visit the Michigan BeachGuard website. 

If you see what looks like a harmful algal bloom, report it to the Michigan Department of Environment, Great Lakes, and Energy (EGLE) by visiting Michigan.gov/HABs and selecting "Report it to EGLE." Be sure to include photos if you can. You can also report a bloom by calling the Environmental Assistance Center at 800-662-9278.