Since bilge water often contains oily wastes, there is a temptation to add detergent to the bilge water and pump it overboard. Fix oil leaks. Before pumping bilge water overboard, capture oil with pads, paper towels or old nylon stockings. Paints can pollute Avoid cleaning boat hulls in the water. Boat hulls coated with copper paints should be hauled out of the water for scraping and cleaning.
Copper can be especially toxic to fish.
Avoid toxic products Read the label. Avoid using toxic products. These products can damage or destroy marine life. Build a smaller, floating dock which does not shade as much nearshore aquatic habitat. Haul out boats for hull cleaning.