When boaters in Atoka County, Oklahoma, set out on McGee Creek Reservoir earlier this year, they expected calm waters and fresh air. Instead, they stumbled upon something that looked straight out of a science fiction movie—large, jelly-like blobs clinging to submerged tree limbs. At first glance, the strange masses appeared otherworldly, leaving onlookers both fascinated and uneasy. What were these eerie shapes lurking beneath the surface, and should people be worried?
The Oklahoma Department of Wildlife Conservation (ODWC) soon provided the answer: the mysterious blobs are bryozoans, also called moss animals. These creatures aren’t aliens but colonies of tiny individuals known as zooids, working together to form gelatinous clusters. Underwater, their bodies feel soft and flexible, but once removed and dried, they harden into a firm shell-like texture. In the right conditions, these colonies can grow quickly, forming clusters large enough to surprise even seasoned boaters.
Despite their unsettling appearance, bryozoans are completely harmless. In fact, they are beneficial to lakes and rivers because they act as natural filters, straining bacteria and small particles from the water. By improving clarity, they help maintain balance in aquatic ecosystems while also serving as food for fish, snails, and mussels. Their presence is actually a sign that the water is healthy and thriving, not polluted or dangerous.
Even more fascinating is their ancient history. Fossil evidence shows bryozoans have been around for nearly 470 million years, making them true survivors of Earth’s changing environments. So while their unusual look may spark curiosity—or even fear—the reality is far more extraordinary. These jelly-like colonies aren’t invaders from another world; they are living reminders of nature’s resilience, quietly keeping our waterways clean for millions of years.