Tiny snails could help stop toxic algae blooms

A Brandon University biologist may have found an unlikely new hero in the fight against toxic blue-green algae blooms, and it’s small, slimy and surprisingly powerful.

New BU research published as the cover story in the international journal Toxins suggests that a common Asian freshwater snail, Sinotaia aeruginosa, could help slow or even prevent cyanobacteria harmful algal blooms (CHABs) that choke lakes, kill wildlife and shut down beaches every summer across Canada.

Yup, snails.

The study, led by Barry Madison from BU’s Department of Biology, found that these snails naturally vacuum up microscopic algae, including Microcystis, the notorious toxin-producing species that creates blue-green blooms.

Just one three-gram snail can filter a couple litres of water in a few hours, and thousands of them working together may act as a natural early-defence system, trapping harmful algae before it can clump into massive, toxic blooms.“What we found is that these common snails naturally filter algae into small pellets,” Madison said. “Once algae is processed by the snail, there’s less opportunity for Microcystis to aggregate into blooms. It effectively delays CHABs during ideal bloom-forming conditions, giving the ecosystem, and the people protecting it, more time before a bloom becomes dangerous.”

In a world where toxic algae blooms are intensifying due to warming waters and fertilizer runoff, the idea that a natural grazer could help buy precious time is catching attention far beyond Manitoba.

These snails are especially good at breaking up the colony-forming cyanobacteria most likely to trigger harmful blooms. While no single tool will solve the complex problem of eutrophication, BU’s findings point to a promising nature-based solution that complements existing mitigation efforts.

Chris LeMoine, Dean of Science at BU, says the work shows how biological research can unlock real-world solutions. “Using species already present in freshwater ecosystems is a creative and sustainable way to support water health,” he said.

Bernadette Ardelli, BU’s vice-president of research and graduate studies, calls the study a major contribution to environmental science. “Protecting water is essential to communities and ecosystems, and this research adds valuable knowledge to efforts happening across Canada and globally.”

Toxic algae blooms aren’t just an eyesore, they can make lakes unsafe for swimming, kill fish, pets and wildlife, threaten drinking water supplies and devastate tourism and local economies.

As blooms grow more frequent, researchers everywhere are searching for cost-effective, scalable, environmentally friendly solutions. BU’s snail research is now a contender.

And yes, before you ask, these snails can even be harvested for food.

» Winnipeg Sun