While taking pictures of ice out, I noticed a lot of debris in the vicinity of where some bob houses were.
Unfortunately, this is controllable debris and the result of someone's carelessness or lack of courtesy. Paraphrasing a backpacker's credo, if you bring it out on the ice, take it back off the ice when you leave.
You could see this type of debris both inside and outside the bandstand area, and I would guess just about anywhere there were bob houses or people gathered on the ice, there will be some debris left behind.