Who Cares About Great Lakes Dredging? These Guys. (slideshow) Michigan Radio Published July 6, 2011 at 1:52 PM EDT Facebook Twitter LinkedIn Email Kate Davidson / Changing GearsEngineer Tom O'Bryan says dredges like this one are basically big vacuums, chewing up sand. We brought the story of the Great Lakes dredging backlogto your radio and computer screen.But sometimes, you need more of a visual. (Even more than my 18 million ovens post.)So click through to my slideshowto meet some of the people affected by sediment buildup in regional shipping channels.