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BRYOZOANS:  A naturally occurring phenomenon

A bryozoan lifted out of the water by the stem of the aquatic plant attached to it
Environment, Great Lakes, and Energy

BRYOZOANS:  A naturally occurring phenomenon

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) often receives complaints claiming that there are gelatinous balls, floating blobs and even “water boogers” some as large as basketballs on the lake shore or in a lake or pond. This phenomenon is due to the presence of bryozoans, also called moss animals, which are not a sign of pollution.

several bryozoan colonies under water with the sun shining through the water onto them.
close-up of a bryozoan colony

View/download a pdf of this brochure.

For more information, including tips to help reduce the amount of nutrients that can enter a lake from your home activities, contact any EGLE district office or call the State of Michigan’s Environmental Assistance Center at EGLE-Assist@Michigan.gov or 800-662-9278.

If you find pollution and believe it is human-induced, please report it to the State of Michigan’s Pollution Emergency Alerting System (PEAS) hotline at (800) 292-4706.