It was during a cruise through the Gulf of California in 1969 that William Hamner, an ornithologist ironically forced out of his profession by an allergy to feathers, found his real calling. The ship was on station, conducting vertical sampling — a process in which large nets scooped local sea life onto the deck so marine biologists on board could see what existed in the waters below. Hamner was not amused. "The animals would come up squashed," he recalls. "They had been crushed by the trawl."
It was hot on deck, so Hamner strapped on a face mask and ventured into the water to cool off. What he discovered beneath the choppy surface was a panoply of beautiful, delicate animals, exhibiting strange behaviors about which virtually nothing was known. It was another world altogether — one waiting to be explored.
Though plenty of researchers were observing the benthic organisms attached to the ocean floor or lurking beneath the tides, few scientists knew anything about the more dynamic pelagic life swimming in the water column of the open sea. "Researchers didn't think there was anything in the top layers of the ocean to look at," Hamner says.
Since realizing they were wrong, the UCLA professor of biology and director of the Marine Science Center has spent the last quarter-century studying everything from the swarming, softball-sized (but harmless) jellyfish living in the saltwater lakes of the Palau Islands — home of "some of the strangest biology in the Pacific" — to the box jellyfish off the coasts of Australia and Southeast Asia, creatures which appear "as harmless as cotton candy" but whose poisonous touch can induce agonizing death within four minutes. For the latter investigation, Hamner safely observed the jellyfish through a clear plastic carousel of circulating seawater he helped develop in order to approximate natural conditions.
But most of the time, he simply dives in and watches. The questions he has investigated reflect the nascence of the science: What kinds of animals are out there? How many of them exist? How do they communicate? When do they congregate? What is the food chain? "We've tried to add a component of real animal behavior and live biology to a discipline that 20 years ago was focused on information about density, distributions and food value," he explains. "We're doing the same kind of biology in the open sea that terrestrial biologists have been doing for 70 years — and there's a huge amount to learn." Indeed. And unlike the bottom-dwellers, life at the top is freewheeling. The behavior of animals that live on the ocean floor or attached to reefs is two-dimensional and site-specific. But nothing is stationary in the open sea. "The behavior of oceanic animals is three-dimensional, like birds and flying insects exhibit," Hamner notes. "Everything's moving around through this big, empty water mass, searching for food and trying to find mates and avoid predators."
Hamner found that the Antarctic krill, for example, swim huge horizontal distances to avoid being eaten by whales. "It's a hide-and-seek game in the open sea," he muses. The krill also group together in large schools. When animal density was determined blindly by using large nets to sample over long stretches, there was no way to know the krill could have an extremely high local density. It took Hamner and his students to see for themselves.
And it's not just life at the top. While the veneer of terrestrial life is relatively thin, life in the ocean extends to an average depth of four miles. "Ninety-nine percent of the living surface on the Earth is full of funny animals that we don't know anything about," says Hamner. "What happens down there in terms of the biology of the animals affects the entire world."
— D.G. |