In the February issue of BoatUS there was a special report on activity taken by several states to ban copper marine anti-fouling bottom paint by 2020. Copper is added to bottom paint as a biocide to prevent slime, plant and zebra mussels from attaching onto the hull. The typical recreational boat sits in her slip much of the time the copper coating in the paint slowly leaches into the water and settles in the bottom. While copper is a naturally occurring element, especially in Michigan, the concentrations in the silt since its introduction in the late 1980s has created a poisonous wasteland in the basins in some of ports and marinas according to the EPA.
Michigan has over 200 marinas and over 900,000 registered watercraft. It’s only a matter of time before the issue hits our shores. Currently only Washington and California are actively taking steps to curb the use of copper bottom paint.
Current alternatives to copper based anti-fouling paint are being developed but have serious environment and cost concerns. Switching to a non-biocide or organic requires stripping the existing coating from the hull. This can cost thousands of dollars and create a copper laden dust which is considered hazardous waste. Application of the new coating requires the use of a sprayer. However has the commodity cost of copper skyrockets environmentally friendly alternatives may be cheaper in the long run.
It may be several years before Michigan lawmakers consider taking similar steps. In the mean time paint manufactures will continue to develop and refine non copper alternatives. Boaters should keep this issue in mind when they prepare their craft for the next boating season.