It's summer! Time for a swim in ... hmm, maybe not that water.
The state of Michigan has added a new entry to its public website for reporting environmental hazards. People can now submit — with photos, please — a report of a suspected harmful algal bloom, or HAB, caused by a growth of cyanobacteria.
The blooms often appear when the water is warmer and the weather is sunny.
Cyanobacterial blooms can contain a number of toxins that can be very harmful to pets that ingest the water, and harmful to people, too, if they swim in — or, for some reason, drink — it. It can cause lethargy and vomiting in pets (that's when to get them to the vet) and it can cause rashes, trouble breathing and other symptoms in people.
Gary Kohlhepp is manager of the Great Lakes Watershed Assessment, Restoration, and Management Section at the state's environmental agency, EGLE.
Kohlhepp said you can usually distinguish non-harmful organic materials in the water, like duckweed, or plain green algae, from cyanobacteria, by swirling a stick in the water. If the stick lifts out strands of plant material, it's not cyanobacteria.
"Typically, with cyanobacteria, there will be a fluorescent green color. The most common way it's expressed is it looks like somebody spilled green paint into the lake," he said. "If you put the stick in and the material disperses when you lift it, and there's really no clumps or filaments, then that would be typical of cyanobacteria."
Warm, sunny weather is one natural contributor to harmful algal blooms. But what's been making them longer and more intense in recent years largely comes down to fertilizer runoff from big farming operations. The state's efforts to curb that source of nutrients that feed the blooms have been unsuccessful.
For more help identifying HABs, you can watch this video from EGLE:
You can also find out if your local lake had a HAB reported before; locations of HAB reports verified by EGLE and results of cyanotoxin testing are displayed on the Michigan Harmful Algal Bloom Reports Map.
But state officials say not all HABs in Michigan are reported to EGLE and therefore may not be on the map. HABs can move around, disappear and reappear, and start and stop producing cyanotoxins. This means HABs may be present in water bodies but not on the map.
