MUSKEGON CHRONICLE (Michigan) 08 June 05 Sickening algae discovered in Mona Lake (Jeff Alexander)
A type of toxic algae native to tropical environments has been found in Mona Lake, the first time the species has been documented in Michigan.
What's particularly troubling about the algae, called cylindrospermopsis, is that it is invisible in water but toxic to the brains and livers of humans and other animals, scientists said.
Cylindrospermopsis is suspected of killing more than 200 alligators over the course of two years in a Florida lake; in 1991, the toxic algae sickened nearly 100 Australians who drank water contaminated by a cylindrospermopsis bloom.
"This is one of the more serious types of toxic algae -- it was implicated in one of the largest cyanobacteria poisonings in Australia," said Rick Rediske, a professor of water resources at Grand Valley State University.
Rediske was part of a team of scientists who documented the presence of cylindrospermopsis in central areas of Mona Lake. "It's been reported in lakes as far north as Indiana, but as far as we know, this is the first occurrence in Michigan," he said.
Rediske said there is no reason for people who swim or boat in Mona Lake to shun the popular waterway. He said the levels of cylindrospermopsis found were very low, and there have been no reports of people becoming ill after coming in contact with the lake.
Still, Rediske and other scientists familiar with the discovery said more tests are needed to determine whether the toxic algae is present throughout the summer, or whether it is an infrequent problem.
Annoesjka Steinman, director of the Mona Lake Watershed Council, said people who use the lake need to become aware of the potential dangers of ingesting toxic algae.
"People are kind of in the dark about toxic algae and its potential health risks," Steinman said.
Cylindrospermopsis is the second type of toxic algae found in area lakes. Last fall, scientists at the National Oceanic and Atmospheric Administration's Lake Michigan Field Station discovered elevated concentrations of microcystins -- toxic chemicals associated with blue-green algae -- in Muskegon, Bear and Mona lakes.
Blue-green algae is easily detected. It creates a mat-like layer of scum on the water surface when it blooms, one that can be bright green to bluish-gray.
GVSU scientists hope to conduct more tests this summer to determine if public health warnings are needed to keep people from coming in contact with potentially harmful blue-green algae in area lakes. Microcystins found in blue-green algae can cause liver damage and other ailments in humans; scientists believe the arrival of zebra mussels spurred the growth of blue-green algae in many of Michigan's inland lakes.
Rediske said cylindrospermopsis thrives in warm lakes that contains elevated concentrations of phosphorous. Scientists studying the issue said Mona Lake, Bear Lake in Muskegon, Spring Lake, and the bayous along the Grand River all have conditions suitable for supporting the toxic algae.
Rediske said cylindrospermopsis probably wouldn't survive in Muskegon or White lakes because those lakes are too cold, and the currents too swift, to support an algae that is native to tropical and sub-tropical climates.
No one knows how cylindrospermopsis wound up in Mona Lake. Some scientists theorize that global warming is allowing tropical plants to survive in northern climates that were once too cold to support those species.
Rediske said people who swim in local lakes should avoid areas where mats of algae are present and water that looks like pea soup.
"Cylindrospermopsis doesn't form a surface scum like other algae," he said. "It could be in the lake and you wouldn't know it, but you would still see the green color in the water."
Sickening algae discovered in Mona Lake