CHICAGO (WBBM Newsradio) — The quick icing of Lake Michigan and the other Great Lakes this week was an interesting sight, but not all that unusual, according to a Chicago biologist.

As a major cold snap gripped the Great Lakes this week, Reports say overall the lakes went from being about 3 percent covered in ice to nearly 9.5 percent ice-covered within five days.

glsea cur Fast Growing Ice Coverage On Great Lakes No Big Surprise To Scientists

(Source: NOAA)

Dr. Philip Willink, senior research biologist for the Shedd Aquarium, said scientists expected this.

“We did notice that the water was getting colder for the past month or so, and we were starting to see a bit of ice in places like harbors, and things like that. So this big jump was not as big a surprise to those who are out there trying to do the work,” he said.

What does the ice do to the lake and the aquatic life within it? Not much.

Willink said fish that usually stay near the water’s surface just go deeper, where it’s warmer.

Cold snaps are fairly routine, and nature just adapts, Willink said.