We've pretty much gotten the message that we - and our dogs - need to look out for blooms of cyanobacterial (blue-green) algae on lakes.
But now they may be popping up on Lake Superior.
Two factors contribute to algal blooms on the big lake: warm temperatures over a period of weeks that warm the lake water, and heavy rainfalls.
There's not a lot of data yet, but those conditions were present in 2012 and 2018 - and so were big blooms of blue-green algae in the big lake.
So a team of researchers led by Bob Sterner of UMD's Large Lake Observatory is on the case - and there's a role for citizen-scientists to play, as well.
The Wisconsin DNR has a great page with a lot of information about blue-green algae and information on how to report a sighting.
"To report an algae bloom email DNRHABS@wisconsin.gov. Include the bloom size, duration, and location with water body name, town name, and county name. Please submit photos for verification including close-ups and overall views."