Never toss any litter overboard, especially plastics. Monofilament fishing line and six-pack rings are particularly harmful to aquatic and bird life. Maintain your boat engine to avoid any oil leaks. Rinse and scrub your boat with a brush, rather than with soap. When removing paint off boat hulls, catch the scrapings in a drop cloth, or sweep and throw them away in the trash.
Bottom paints contain copper or tin which are extremely toxic to aquatic life.
Don't dump trash in caves or sink holes. Don't mix pesticides or herbicides near water wells. Make sure well heads are properly sealed and covered to prevent pollutants from entering the aquifer. Keep domestic animals out of streams, springs, and wetlands. Do not kill unwanted vegetation with used motor oil, gasoline, or kerosene.