Build a monofilament fishing line recycle bin for your public access. (a great project for your lake association).
When disposed of improperly, monofilament can be hazardous to marine life, scuba divers and even boat propellers. Even when put in the trash monofilament can end up harming wildlife at landfills. When possible it is best to recycle used fishing line.
What you need:
2 foot section of 6 inch PVC pipe
An instructional video showing how to build one is available from Boat US Foundation. They also have free decals (see the below link).
Make sure to clean out the bin at least once per month. Wear gloves when you clean it as people may have discarded fish hooks along with the fish line.