- Author: Leigh Taylor Johnson
Boaters paint a boat hull with copper antifouling paint and expect it to prevent fouling organisms from growing on the surface. Evidence is growing that some invasive, and even some native, hull fouling species have developed the ability to tolerate copper. Further, copper paints have come under regulatory scrutiny.
Boaters are asking for effective alternatives. This leads me to ask, “What does ‘effective’ mean?” I propose that it means the ability to keep fouling under control in a manner that is technically feasible, environmentally friendly and in line with costs for using copper antifouling paints. How do we do that?
Integrated Pest Management, or IPM, may help us to set a new course. According to the manual, IPM In Practice (by University of California Agriculture and Natural Resources), the general approach is to suppress pests over the long term in the least disruptive way that is possible. It often combines biological, cultural, mechanical, physical, and chemical methods and considers the risk that pests will develop resistance to pesticides. I’d like to suggest that we start talking about IPM for Boats!
How can we apply IPM to hull fouling control? In-water hull cleaning is an example of mechanical control. Slip liners and boat lifts are examples of physical control. Antifouling paint is an example of chemical control. Less toxic and nontoxic hull coatings are environmentally friendly.
Cultural control could use the ecology of hull fouling species to guide application of other methods. We’ll be including this IPM approach in future publications and blog posts about our research on fouling control ecology.
Cost effectiveness is an issue for boaters who need to replace copper antifouling paints and want to avoid using another toxic product. We are compiling long-term costs for using durable, nontoxic epoxy hull coatings from boats that participated in our 2002-2003 field demonstration. We expect to be able to report results later this year.
Meanwhile, you can read about our 2007 check-in with boat owners from our field demo to see how the nontoxic coatings were doing five years after they were applied. Visit the Nontoxic Antifouling Strategies page of our website and click on Nontoxic Hull Coating Field Demonstration: Long-Term Performance 2007 Update.
My thanks to Cheryl Wilen, Area Integrated Pest Management Advisor in Southern California, for assistance in learning about the principles of IPM and how we can apply them to hull fouling control!