Leave the Nautilus Alone

The nautilus is an amazing creature, roaming the Indo- Pacific water for the past 500 million years. But if a dive boat you're on pulls one out of the water to show passengers, tell them to throw it back. While the nautilus has adapted to everything from asteroid collisions to climate change, this living fossil is dying off in zoos and aquariums around the world, and exhibiting them on dive boats is not helping.

A team of scientists in Washington D.C. wanted to know why the nautilus can live 15 years or more in its natural habitat but only up to three years in captivity, so it studied captive mollusks from the city's National Zoo. In a study published in Zoo Biology, they state that once the nautilus is removed from its natural environment, a thick, rough, black substance develops on a portion of its smooth white shell. The substance is a heavy protein that leads to excess amounts of copper, which can be harmful to shell formation. Researchers think it's caused by environmental stress from being in captivity.

In the wild, overfishing has slashed nautilus numbers by as much as 80 percent in once-rich areas like Australia's Great Barrier Reef and the Philippines' Bohol Strait. With virtually no international sanctions limiting the capture and trade of the nautilus, shells can sell for several hundred dollars. The United States alone imports 100,000 nautilus shells each year. But for the nautilus's sake, divers and dive boats should just leave them alone -- and untouched -- in their natural habitat.