In August of 2010, Ken Koski, floated along, enjoying his hobby of 30-plus years: snorkeling on Lake Charlevoix near his East Jordan home.
Soon, he found himself surrounded by what he thought were seeds cast off from cottonwood trees.
But it was August, he realized. There were no cottonwoods above where he swam -- and the little seeds were undulating.
"They looked like little umbrellas, folding and extending," he said.
What "they" were was craspedacusta sowerbyi: a type of freshwater jellyfish, one of few in the world. And though the freshwater jellyfish are not newly invasive in the United States, this was the first time anyone reported seeing them this far north in Michigan.
"They've shown up in Michigan, but not Northern Michigan," said Randy Claramunt, a research biologist with the Charlevoix Fisheries Research Station.
The jellyfish are approximately the diameter of a quarter, with tentacles -- just as you might imagine a jellyfish to look.
"It's almost if you were to ask a kid to draw a stereotypical jellyfish on a piece of paper. That would be these freshwater forms," Claramunt said.
Though the jellyfish have been found in the United States since the 1920s, Koski's finding marked the first such discovery in Lake Charlevoix, the first in the Lake Michigan basin, and the first so close to Lake Michigan.
"I was just so damned excited," said Koski. "I made a beeline to tell someone at home, and there was nobody here. Even the dog was gone."
To bloom, the jellyfish require a specific set of conditions. Their ideal habitat is a warm, temperate climate.
But that's only part of it.
"They only bloom if the water is extremely warm and there is a lot of food," said Claramunt. "They are only abundant if food is very abundant."
The jellyfish, which eat zooplankton, fish eggs and brine shrimp, are not harmful to humans. They can reproduce asexually, which means they can remain dormant if the conditions are not favorable, which is likely what is happening this summer. Because spring months were so cool, said Claramunt, it is not likely that we will see a bloom this August.
And though the jellyfish is an invasive species, because they bloom so infrequently, they do not seem to be causing the kind of harm other invasives such as zebra mussels cause. Rather, Claramunt said, the jellyfish should be regarded as an indicator of the sort of environmental changes that may be occurring in Northern Michigan.
"It's more of an alarm bell going off. The fact that we're seeing them make some people wonder if aquatic systems are undergoing a lot of change," said Claramunt. "There is certainly a change in the warming and productivity of the freshwater ecosystems in Michigan ... it's not just every year they get warmer. We're seeing wider fluctuations in temperature -- that means peaks and lows. It's just not as stable."
That we have seen jellyfish for the first time in Lake Charlevoix indicates that the lake hit an extreme temperature.
"In a lake like Lake Charlevoix, this far north, it's really odd," said Claramunt.
But while the jellyfish might indicate a temperature not yet seen in the area, seeing the jellyfish bloom is no doubt a novelty.
"I miss them," said Koski. "I kind of wanted to see something again this year."