Plastic Pollution in the Great Lakes - and a Surprising Critic of the Report

While I've always been concerned about plastic pollution in the oceans, commonly wrapped up as the 5 Gyres matter, living near the North American Pole of Inaccessibility has made that pollution a distance concern (pun intended). Any of the plastic bags I see floating down the street will never make it to the ocean.

But when reports came out that the Great Lakes were similarly afflicted with plastic pollution, well, that struck closer to home (again, pun intended). Lake Superior is a beautiful lake less than 3 hours from here, one that I have visited countless times. Lake Michigan is a little farther, but one that I still see with great regularity. The waters are clear, cold and beautiful and need to stay that way.

What is most concerning - and surprising - is that the lakes were reported to have an even higher concentration of pollution than the oceans do. I say surprising, for a couple of reasons. First, the lakes are continually "flushed" as rainwater runs into and out of them, whereas the oceans are at the bottom of the hill. (This is the same reason that oceans are salty and the lakes are not. The salt in the lakes is carried into the oceans and accumulates there.) But secondly, the oceans have well established flow patterns, including gyres, and these gyres are what are necessary for the concentration of pollutants in the ocean. Without them, the pollution would be concentrated near their source - the shorelines. I have yet to see any documentation that the Great Lakes have gyres.

But what really struck me as odd was the criticism that the report received after it was published. Or more accurately, who it was that was criticizing the report: the 5 Gyres Organization. The very same group that supported the research. The criticism can be found here (scroll down to the 3rd comment from Stiv Wilson). In part, he said:

"I took these two samples on the 5 Gyres/Fredonia Great Lakes expedition that yielded so many pieces- but to say this constitutes a higher density than the ocean is false. The average ocean sample has about a third of the individual fragments as the two samples from Lake Erie. But they are way way way smaller than what you find in the ocean, not just smaller than 5mm but smaller than .5mm, so by weight, the concentrations in the Great Lakes are a fraction of what’s in the ocean..."

Stiv and I have crossed paths before (be sure to read the exchange in the comments) so his further comments at the Ecowatch page that " Heck, I’m public enemy number one with the plastics industry, but I work on facts, and this article pushes the bounds of reality and journalistic due diligence." self-referentially pushes the bounds of reality and journalistic due diligence.

What's going on? My guess is that Stiv is concerned that this report would divert focus from the oceans - his predetermined cause - to the Great Lakes. But if that is what the numbers ultimately show, well, someone who "works on facts" will just have to accept that.