Courtesy of M. Carroll/Harbor Branch

A researcher at the Harbor Branch Oceanographic Institution processes samples of deep-sea sponge to isolate disease-fighting chemicals.

Marine biologist Amy Wright of Harbor Branch Oceanographic Institution in Fort Pierce, Florida, has tracked down a long-lost sponge, believed to contain a potent anticancer compound. She and her colleagues first found marble-size chunks of the creature in 1984. Tests on mice and on human cells showed that the sponge could arrest cancer, but scientists did not have a large enough sample to do further research. Using clues from the original find, Wright deduced the sponge’s likely habitat and located it on her very first submarine dive using this new information. The sub’s robotic arm located the sponge and collected enough to resume the search for a cancer cure.

The sponge eluded scientists for 20 years because it lives in what researchers refer to as “the dead zone,” a relatively unpopulated depth of the Caribbean. “We don’t usually study this zone, because every time we’ve done it, we haven’t found much,” Wright says. Her team is now scrambling to isolate an anticancer drug from the gray, rock-hard sea creature. The compound might help the animal defend against predatory fish, or it might actually be produced by symbiotic microbes living on the creature’s surface. Wright has found many curative compounds in other sponges and bacteria and doesn’t always care that she cannot figure out their original function. “Fortuitously, they work in mammalian systems like ours,” she says.