August 7th, 2013 – Chicago, Illinois
We’ve arrived! Under luminous skies and the smoke filled harbor from the canon fire of a dozen tall ships, we simultaneously finished our 29th trawl in Lake Michigan. Each one had a few bits of plastic, but really small stuff. Larger debris, with a wind profile, skirts across the lake to one shore or another, so you’ll find single-use plastic waste on beaches. It’s the small stuff that stays in suspension near the water’s surface, and is affected by currents more than wind.
We did find microbeads, the same you might find in facial cleansers. And in some toothpastes. I know it sounds crazy, but many of these facial cleansers contain hundreds of thousands of 1/3 millimeter plastic beads designed to scrub your face and then wash down the drain. You can follow our campaign on the 5Gyres.org website to learn more and help us to pressure Proctor and Gamble to stop using them in their products and use environmentally harmless materials, like crushed apricot seeds and cocoa beans, which some of their competitors already use.
But are those microbeads accumulating in the Great Lakes? What we know is that currents in Lake Michigan do rotate in the southern half, what you might call a “mini-gyre”. We studied the work of Beletsky et al. (1999), which shows what average summer currents in the lake do. We ARE finding microbeads here. We’re only half-way done with our three week Lake Michigan expedition. Unfortunately, I’m sure we’ll find more.
Beletsky, D., Saylor, J.H., and Schwab, D.J., 1999. Mean Circulation in the Great Lakes. Journal of Great Lakes Research 25, 78-93.