Barnacles and other marine organisms that grow on the hulls of ships present a big problem to vessel operators. Such biofouling, as it is called, slows ships down, causes them to burn more fuel, and requires that they be taken out of service every couple of years to be cleaned. Scientists are turning to nature for solutions.
Consider: Studies have revealed that the skin of the long-finned pilot whale (Globicephala melas) has self-cleaning abilities. It is covered with tiny ridges, called nanoridges, which are too small to allow barnacle larvae to get a good grip. The spaces between these ridges are filled with a gel that attacks algae and bacteria. The whale secretes fresh gel as it sheds its skin.
Scientists plan to adapt the whale’s self-cleaning system for the hulls of ships. In the past, antifouling paints were applied. Yet, the most commonly used of such paints have recently been banned because they are toxic to marine life. The researchers’ solution is to cover ships’ hulls with a metal mesh over an array of holes that exude a biosafe chemical. The chemical thickens into a viscous gel on contact with seawater, forming a skin that coats the entire hull. In time, this skin, about 0.7 millimeters [0.03 in.] thick, wears away, taking with it any organisms that may have been hitching a ride. The system then secretes a fresh coating of gel to cover the hull.
Laboratory tests have shown that this system could reduce biofouling of ships 100-fold. And that would be a huge advantage for shipping companies, because bringing a vessel into dry dock for cleaning costs a great deal of money.
What do you think? Did the pilot whale’s self-cleaning skin evolve? Or was it designed?