Do it, man. Sounds worthwhile if it's trashing the place.I always have a plastic grocery bag with me and have the kids collect trash along the shoreline. It is sad but we fill it in no time!
At our local pond I was getting real disappointed that so many people were trashing the place. That was until I went on a windy day and saw the wind whip the trash out of the trash cans around the park and realized that was probably the source of most of the litter. That and the damn squirrels!
Which reminds me, I wanted to call Parks and Rec and see if they would be willing to figure out some kind of lid for the cans.