Antarctic Unsavory to Shipworms: Currents and Polar Front Keep Destructive Mollusks at Bay

Article excerpt

Quirks of ocean currents may have turned the waters around Antarctica into a rare sanctuary for wooden shipwrecks, free of the destructive mollusks known as shipworms.

A 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 attracted bone-eating worms but the wood emerged "pristine," Dahlgren and his colleagues report August 14 in the Proceedings of the Royal Society B.

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Offshore Antarctica is a terrible habitat for wood borers because the continent probably hasn't grown trees for at least 30 million years. And research on other marine species has suggested that the Antarctic circumpolar current and the polar front can block some invaders from moving in. …