Ocean currents and polar front form 'moat' that keeps destructive mollusks at bay
Courtesy of Adrian Glover/Natural History Museum
Quirks of ocean currents may have turned the waters around Antarctica into a rare sanctuary for undiscovered wooden shipwrecks, free of the destructive mollusks known as shipworms.
The front formed by the junction of frigid polar and warmer waters as well as a strong current circling the continent may block tiny shipworm youngsters from moving in, says Thomas Dahlgren of Uni Research, the University of Bergen’s partner research company in Norway.
Fourteen months after leaving wooden planks and whale bones underwater on western Antarctica’s continental shelf, researchers found no evidence of wood-boring mollusks. Whale remains sprouted bone-eating worms but the wood emerged “pristine,” Dahlgren and his colleagues report August 14 in the Proceedings of the Royal Society B.
In most other ocean waters, including the Arctic, mollusks that specialize in boring into wood typically show up within months, Dahlgren says. Yet off-shore