Copper Tolerance of Hull Fouling and IPM

sitenum=96

Environmental issues affecting recreational boat owners and boating businesses @UCANRCoast

Posted By: Leigh Taylor Johnson
Written by: Michelle Lande, Leigh Johnson and Carrie Culver

Published on: October 24, 2011

A growing body of science is finding that many fouling species can tolerate copper antifouling paints. Although many boat owners know they must clean copper hull paints, the extent of copper tolerance reported by scientists is surprising.

Some invasive fouling species, and even some native species, can attach directly onto copper antifouling paint and can also dominate in copper polluted environments. This has implications for the effectiveness of copper antifouling paints, but also for the importance of having a clean harbor or bay.

Copper-tolerant species also provide an opportunity for other, less-tolerant species to hitchhike on a hull coated with copper antifouling paint. The science shows that copper-sensitive species can attach, grow and be carried within the folds and crevices of more tolerant species.

Copper-based paint is the dominant antifouling strategy. Yet, copper tolerance studies make it clear that antifouling paint, or “chemical control,” may not be able to do the job, alone. They support the need for an integrated approach (see May 23, 2011 blog post “Integrating Hull Fouling Controls – IPM for Boats!”).

An in-depth discussion of the science behind copper tolerance can be found in our fact sheet “Hull Fouling and Copper Tolerance – 2011 Scientific Review.” You can access it on the Nontoxic Antifouling Strategies page of our website.

The photo below shows 12 months growth on copper antifouling paint in San Diego Bay - from our field research.

Copper antifouling paint with 12 months growth in San Diego Bay reduced

Tags: antifouling paint effectiveness (1), copper tolerance of hull fouling (1), fouling growth on copper bottom paint (1)

Comments: 6

Comments:

by Frank Szafranski

on October 28, 2011 at 1:23 PM

This is a naked attempt to justify an anti-copper position that is based on political expediency and not facts. Sorry Leigh, but i can't buy into this.

Reply by Leigh Taylor Johnson

on October 28, 2011 at 2:18 PM

Thanks for bringing this up, Frank. We consider it part of a larger issue we recognized back in 2004. We thought that boat owners could be caught between efforts to reduce copper levels in harbors and efforts to encourage use of copper antifouling paints to reduce risks of transporting invasive species. Through our investigations we learned of research on copper tolerance and published two earlier fact sheets. Since then, the field of research on hull fouling species and copper tolerance has grown, leading us to publish the longer fact sheet in 2011 that is mentioned in the blog post. Interestingly, we learned that several invasive hull fouling species could tolerate copper antifouling paints and/or harbors polluted with copper. I commend the many coating companies that are developing a variety of new approaches for fouling control. Such choices will be especially valuable for boat owners home-ported in highly invaded harbors and those facing restrictions on levels of dissolved copper.

by Scott Hogan

on March 16, 2012 at 11:45 AM

The answer is safe epoxies and mechanical removal of the offending organisms/fouling, whether by getting the vessel up to a high top speed for sustained periods, or, paying someone to remove the fouling by water jet, or gentle scraping. By combining a coating with very low surface energy and regular maintenance, fouling can be controlled without the use of heavy metal toxins and ablative systems. We do it all day, every day. Naturally, I am biased (I work at Plastic Maritime www.wearloncorp.com, where we manufacture safe foul-release coatings for the shipping markets.).
The challenge is convincing people/companies/organizations to CHANGE their current process. It is human nature to become complacent. It becomes crucial to show industry that they can increase their bottom line, while affecting a marketable change.

Reply by Leigh Taylor Johnson

on March 16, 2012 at 12:01 PM

Thanks for your comments, Scott. Using a suite of methods for fouling control can be very effective. Given copper tolerance of some hull fouling species, such an integrated approach is likely necessary at least in some areas. We are suggesting that IPM (integrated pest management), which was developed for agricultural and structural pest control, be applied to boats. Our forthcoming tech report, IPM for Boats, will go into more detail - stay tuned!

by wc diving...

on May 31, 2012 at 3:07 PM

Are you a boat owner and considering transitioning to copper-free hull paint? Some are skeptical about the performance of these new paints, largely because of the high cost. As a Eco-friendly company, we at West Coast Diving are interested in determining whether the benefits of these new paints justify the costs. Of course, price is important but it’s not the sole factor when it comes to reducing pollutions in the environment, but are the copper-free paints really the answer to cleaner water in San Diego harbor?

The copper that is being released into the water is considered to be a danger to our environment, and according to environmental experts should be monitored and controlled, the truth is that most pollution comes from other sources such as:

Toxic vessel cleaning products – non-toxic cleaning products should be used for all vessel and marina cleanings
Plastic water bottles and other plastic waste – Currently littering laws are being strictly enforced and if you happened to be a litter bug, watch out – the penalties are stiff.
Storm water pollution prevention – preventing runoff – environmental studies have shown that the type of metals released from vessel paint containing copper and other pollutants add up to a fraction of this problem. Most of these metals and other types of pollution enter our water through storm drains. The solution would be a responsible maintenance and adherence to the environmental guidelines.
Proper discharge – All vessels with holding tanks MUST be pumped out at proper facilities on shore.
Oil Spill Prevention – Most marinas already have this in place, but we must emphasize the importance of oil spill kits being available at all marinas as well as being on board race management boats during competitions etc. and it is important to use fuel spill pads when fueling.
Boat Maintenance – Any Maintenance conducted on vessels should be done in covered areas with vacuums available to clean up all dust.
Bottom Paint – Non-toxic, copper-free bottom paint would reduce the pollutions. As we mentioned before, it’s pricey and even with the financial help the Port is currently offering for boat owners to replace copper-based paints, some owners may still not be able to afford this change.

Divers that perform underwater hull cleaning know that the new copper free paints do not seem to prevent regrowth as effectively as the current paints do. This also makes switching to copper-free paints somehow less attractive because it means that your boat maintenance cost is increasing as well.

Another thought that comes to mind is that our military vessels do not use environmentally-friendly products while substantially impacting harbor environment and the whole effort of re-painting recreational boats may not produce any tangible positive effect on the local ecosystem.

We all want to protect and preserve our precious waterways but we must do it with a careful assessment of the situation and base our decisions on real facts. We also have to consider as to what we can afford as boat enthusiasts to lessen our impact on the environment. One thing is certain, everyone needs to contribute by responsibly operating their boat and while performing their maintenance.
What do you think?
West Coast Diving completely supports any effort to help preserve and reverse the pollution of our waterways, but we do not advocate that placing burden on the pocket books of boat owners is the only way to make progress. We educate our clients on the most effective approach which both help to keep environment safe while providing affordable solutions.

Reply by Leigh Taylor Johnson

on June 1, 2012 at 10:38 AM

Thanks to West Coast Diving for discussing a broad range of pollution prevention activities for boaters, boating facilities and boat service businesses. The California Department of Boating and Waterways' Dockwalkers Program is a great place to learn more about what you can do to keep your harbor, marina or yacht club waters clean. Volunteers are trained by DBW, Santa Monica Bay Restoration Foundation and others around California to educate boaters on pollution prevention. They have fun while they reach out to boaters on docks and at boating events to get everyone involved in being part of the solution to pollution!