STRATFORD - A group of more than a hundred volunteers gathered today on the shores of the Housatonic River in Stratford for a marathon cleanup operation.The participants of the event set off from the Birdseye Boat Ramp, dragging out of the water a variety of items, among them a mattress spring, tires and pieces of trees. John Valentino, the chairman of the Housatonic River Cleanup, says the annual cleanup has made a difference, with the water going from brown to blue over the past five or six years. "It's a little bit bluer now, you can see a little bit further down," he says.Organizers of the cleanup say the recent floods may be partially responsible for the large piles of trash in the river, but they say residents should be more careful about the way they dispose of their refuse.