A graduate student rushes into Barbara Block's office to show her his latest findings: a graph charting the breeding behavior of Atlantic bluefin tuna in the Gulf of Mexico. Block is thrilled at the detailed, never-before-seen results. "It's spectacular," she says. Thanks to new technology, "we can see what a tuna does every second."
Block, an associate professor of biological sciences, works at Stanford's Hopkins Marine Station, a low-key set of buildings in Pacific Grove, Calif., sandwiched between the Monterey Bay Aquarium and Lovers Point. While tourists cruise in and out of outlet stores, locals jog along the poppy-strewn cliffs and sea lions bask in the sun, Hopkins scientists are studying, among other things, the sex lives of tuna.
It's no ordinary voyeurism. As Block puts it, "how do you study an organism that weighs 1,000 pounds and has as its home range the entire Pacific Basin or the entire Atlantic?" The answer: you attach electronic tags as small as a pack of gum--or as large as a hand-held microphone--to the animals. The tags cost $500 to $3,500 apiece and either record data or transmit it to researchers via satellite for several years. They're like highly efficient graduate students, Block says--only they work day and night and don't need a stipend.
Block and colleagues from Hopkins and the Monterey Bay Aquarium will soon apply their tuna-tagging techniques to several additional species as part of the first census of marine life. In a project called TOPP, for Tagging of Pacific Pelagics, the researchers plan to track about 3,000 open-sea dwellers, including elephant seals, leatherback turtles and albatross. The goal of the census, which involves biologists and oceanographers from around the world, is to learn about what used to live in the ocean, what resides there now and what will inhabit its waters next. The information, says Block, is important for conservation efforts.
In preparation for TOPP's kickoff in 2003, Block and her colleagues have tagged eight Pacific tuna. Meanwhile, the results from 475 Atlantic bluefin continue to roll in. So far, the researchers have recorded 13,500 tuna days, including body temperatures, migratory patterns, ocean depths, favored feeding grounds--and yes, even those breeding habits.
