Harmful Algal Blooms: What Grand Rapids Families Should Know

Harmful Algal Blooms in Grand Rapids, Michigan

Summer in West Michigan means time on the water, from Lake Michigan beaches to the Grand River and inland lakes across Kent County. When the weather turns warm and water moves slowly, some lakes and ponds can develop harmful algal blooms (HABs). These blooms can look harmless but may make people, pets, and livestock seriously ill, so it helps to know what to watch for before you swim, fish, or let your dog wade in.

What Harmful Algal Blooms Are

Harmful algal blooms are the rapid overgrowth of algae or cyanobacteria in water that can harm people, animals, and the environment. In fresh water like lakes and rivers, they are most often caused by cyanobacteria, also called blue-green algae.

Not all algal blooms are harmful. But some cyanobacteria produce toxins, and you cannot tell whether a bloom is toxic just by looking at it.

How to Spot a Bloom

Blooms do not always look the same. They may appear as:

• Foam, scum, or mats on the surface of the water
• Water that looks discolored: green, blue, brown, or red
• A bad smell coming from the water

Keep in mind that not all blooms are visible or easy to spot. When in doubt, treat the water as unsafe.

Why Blooms Happen

Algae and cyanobacteria grow quickly when water is warm, slow-moving, and high in nutrients. Those nutrients often come from:

• Fertilizer
• Sewage
• Stormwater runoff

Warming water temperatures can make blooms more common, which is one reason late summer is a higher-risk time on Michigan lakes.

The Toxins and How They Affect the Body

Some cyanobacteria make toxins that can affect the liver, kidneys, and nervous system. These include:

• Hepatotoxins, such as microcystins
• Neurotoxins, such as anatoxins and saxitoxins
• Cylindrospermopsin

People and animals get sick by:

• Touching the water
• Breathing in airborne water droplets or spray
• Swallowing contaminated water, fish, or shellfish

Symptoms to Watch For

Skin contact or breathing in droplets can cause:

• Rash
• Eye and nose irritation
• Sore throat
• Cough

Swallowing contaminated water or food can cause:

• Stomach pain, vomiting, and diarrhea
• Headache
• Muscle weakness
• Dizziness
• Liver damage

Illness can range from mild to life-threatening. If symptoms are severe, call 911.

How to Prevent Illness

A few simple habits go a long way when you are out on West Michigan waters:

• Stay out of discolored, scummy, or smelly water.
• Keep children and pets away from water that may have a bloom.
• Check for and follow local swimming, fishing, and shellfish advisories before visiting lakes, oceans, or other water. The Kent County Health Department is a good place to look for local water advisories.

If you, your child, or your pet goes into water that may have a bloom, rinse off with clean tap water right away. If a bloom affects your drinking water supply, follow guidance from local officials.

A Note on Supplements

Some products contain blue-green algae. Talk with a health care provider before taking blue-green algae supplements or giving them to a child, since these supplements can be contaminated with toxins. Your primary care team at Corewell Health, Trinity Health Grand Rapids, University of Michigan Health-West, or Cherry Health can help you decide what is safe.

Protecting Pets and Livestock

Animals are especially vulnerable. Pets and livestock can become very sick or die within hours of contact with toxic blooms. Dogs are at high risk because they may swim in scummy water and then lick the toxins off their fur.

• Do not let pets drink from or swim in water that looks discolored, scummy, or smelly.
• Rinse pets with clean tap water if they have been in questionable water.
• Contact a veterinarian immediately if an animal seems sick after being in or near affected water.

What to Do if You Get Sick

There is no antidote for HAB toxins. Treatment is supportive and aimed at relieving symptoms, so getting care early matters.

• If you think a harmful algal bloom has made you sick, contact a health care provider or call Poison Control at 1-800-222-1222.
• For a medical emergency, such as trouble breathing or severe weakness, call 911.
• For pets or livestock, call a veterinarian right away.

Harmful algal blooms are a normal part of warm-weather life around Grand Rapids, but a little caution keeps your whole family, including the four-legged members, safe. When the water looks off, stay out, rinse off, and check local advisories before heading back in.