for National Geographic News
Whether you're a ship or a shark, you need a sleek surface to speed through the sea. Which is why barnacles, algae, and other marine organisms that glom onto hulls or bodies are such pests.
To know what sailors are up against, consider this: Barnacles produce an epoxy-like cement that can stick to Teflon, not to mention hulls and rudders.
Such "biofouling" speeds corrosion and increases drag resistance, reducing speed and maneuverabilityat a cost of billions of dollars a year to the maritime industry.
"Any surface that is submerged in seawater could be fouled," said Staffan Kjelleberg of the Centre for Marine Biofouling and Bioinnovation at the University of New South Wales in Sydney, Australia.
Shipwrights once covered wooden-hulled ships with lead, copper, and other metals to thwart biofouling. In more recent times, shipyards have typically painted hulls with toxic paints.
Today, such environmentally harmful products are facing tougher regulation, and scientists are hard at work searching for green alternatives.
Some researchers are seeking more environmentally friendly paints, which could employ chemicals or compounds found in marine plants naturally resistant to ocean pests.
Other scientists are exploring ways to develop marine surfaces inspired by Mother Nature.
Artificial Shark Skin
Antonia Kesel and Ralph Liedert, at the University of Applied Sciences in Bremen, Germany, has created an artificial sharkskin that mimics natural sharkskin's innate resistance to biofouling.
"All marine animals and plants need a reliable strategy against unwanted overgrowth by fouling organisms such as mussels, algae, and barnacles," Liedert said.
"Most fishes use either slimes, toxic substances, or regular skin-peeling as a way to get rid of parasites. However, sharks don't possess these kinds of mechanisms."