Finding the chemical weapons.

Because sponges and other stationary animals on the ocean floor can't flee when confronted by a hungry predator, they often develop protective weapons. Some animals take the brute force approach, forming hard shells or spines, while others fashion chemical defenses to keep away starfish and other attackers. For the last few decades, biologists have studied chemical weapons in the crowded ecosystems of the tropics, but several researchers have recently turned their attention to the less diverse waters around Antarctica.

Most oceanographers presumed that stationary animals in the polar regions would need fewer chemical defenses than their tropical counterparts because polar ecosystems have far fewer species, suggesting animals there might face fewer potential predators. But work over the last few years by James B. McClintock of the University of Alabama at Birmingham shows that despite their relatively spare ecosystem, stationary Antarctic animals employ chemical defenses just as often as their tropical cousins.

McClintock and William Baker of the Florida Institute of Technology in Melbourne are now trying to identify which particular chemicals protect these animals. Some of the weapons may work by killing predators; others could simply taste bad; still others might help prevent bacterial and other harmful organisms from establishing a home on the stationary creatures. Although the project aims to help biologists understand how animals protect themselves, it could also have far-reaching effects, says Baker, who believes some of these defensive molecules may have uses in fighting illnesses in humans. He routinely sends extracts of the animals, as well as isolated molecules, to drug companies for testing.