Forty feet below the surface of the Pacific Ocean, off California's Anacapa Island, Gary Davis searches the rocky bottom for a rare sea creature. A strong current pushes the kelp forest to a 45-degree angle as Davis, garbed head to toe in Neoprene to combat the chill of the water, slithers through the wavy thicket until he comes upon a cage.
Davis, a senior scientist with the National Park Service, is on the prowl for baby abalones. He pulls a knife from a sheath attached to his dive computer—a calculator-sized device, strapped to his air hose, that measures ascent rate, depth and temperature, among other things—and cuts a wire holding shut a two-foot-square cage filled with cinder blocks. Amid a swirl of silt and sand, he pulls out the dozen or so M-shaped slabs, which offer protection from predators, and turns them over to see if any baby abalones have taken up residence. A year ago, in an effort to jump-start the population, he purchased 600 adult abalones from a wholesaler for $19,200, placed them in an 1,800-square-foot refuge area where he had set up seven cinder-block-filled pens and waited for nature to take its course.
Alas, after checking the cages with the help of five other biologists, Davis finds that no baby abalones have attached themselves to the blocks. He's not surprised, though; it takes about 18 months for the larvae to reach the size at which they attach themselves to a surface.
The 52-year-old Davis has been assessing marine populations for nearly 30 years, since earning a master's degree in biology from San Diego State. But for all the enthusiasm Davis shows for his work, each year he has found less and less to assess. The decline in the number of abalones off Anacapa, presumably a consequence of overharvesting, prompted his innovative breeding experiment. A broader worry, the dwindling populations of many forms of marine life, led him to launch a more ambitious project: the Great American Fish Count, held the first two weeks of July at popular dive sites in California, Florida, Texas, Georgia and even Colorado and Iowa.
"We needed to do something to get people's attention," says Davis, who began the program in the waters off Anacapa, near San Diego, in 1992 with 50 volunteers who identified 27 species and counted 4,804 fish. "What's happened to the abalone is a good indication that the sea is not an endless bounty."
About 1,000 counters at 30 sites are expected to take part in this year's aquatic census, which starts July 1; they'll count thousands of fish. "There's a certain guardianship to it, which there has to be if we're to recognize that the oceans are not infinite," says Sarah Tamblyn, who, as president of the Marine Conservation Network in Danville, Calif., has run the count there for three years. "The title is pretty catchy. People wonder, How do you count fish—they're moving?"
Good question. The answer is, you don't count every last one. Armed with underwater slates and timers, divers estimate a particular species' abundance. After each sighting they ask, Did I just see one fish? Two to 10? Eleven to 100? Or more than 100? They check off the appropriate category on their slate. They also note the time when they first encounter a particular species.
"The idea is to go to your favorite dive spot, have a good time and make two or three dives, but designate one of them as the fish-count dive," Davis explains over the rumble of the diesel engines as the research vessel, Pacific Ranger, makes its way back to port. "Once they're trained to recognize all the fish, recreational divers don't have any trouble with it, and they have fun doing it."
Davis based his idea on the National Audubon Society's annual Christmas Bird Count, which began in 1900 with 28 observers primarily in the Northeast and now involves 45,000 birders each year in close to 1,700 locations worldwide. "Before 1900 it was traditional to go out the weeks before Christmas and shoot all the birds in the neighborhood and put them in pies," Davis says. "We lost passenger pigeons and other birds to that. Then somebody decided to get people to look at the birds, put names on them and get to know who's in the neighborhood—then, maybe, people would care more about them. It raised public awareness. I thought, Let's do that for fish."
The bird count has been so successful that it has helped to effect change. In the mid-1970s the U.S. Fish and Wildlife Service reviewed 25 years' worth of the Audubon Society's bird-count data to confirm a decline in the population of the American black duck. "It allowed them to alter hunting limits and do studies to figure out where the problem was. As a result, the population has stabilized," says Geoff LeBaron, Audubon's Christmas Bird Count editor. "Citizen science is going to become more and more important as time goes on and funding gets scarcer and scarcer. You need some kind of baseline to recognize that there is a problem. The more long-term monitoring programs like the fish count, the better."