It's 5:30 A.M., AND THE LOBSTER DOC is making her monthly house calls in the intertidal zone.

Biologist Diane Cowan flips over seaweed-wrapped rocks left exposed to the air only at the lowest of low tides. She grabs the juvenile lobsters hiding underneath, some of them as small as jellybeans, others as large as hampsters. She inspects and measures about 30 baby lobsters in the dawn light, injecting tiny metallic tags into their muscle tissue.

"Oh, lobbies," she coos at them soothingly, even as they rear their baby claws defensively and thrash around in margarine containers. But she also finds them tasty. "I'm definitely going to see you on my plate someday," she says, addressing a hearty youngster.

Cowan, who has been called the Jane Goodall of lobsters," is a mediator of sorts in an intensifying lobster war. A fierce debate is raging between lobstermen, who are bringing in astronomical catches, and scientists and regulators, who warn that the overreliance on juvenile lobsters — too young to have produced many offspring — threatens the longterm viability of the lobster population.

But what is missing amid all the heated rhetoric is conclusive data. That's where Cowan comes in.

Founder and head scientist of the Lobster Conservancy in Friendship, she enjoys the respect of both camps. For eight years, she has been tagging juvenile lobsters, building a database and learning about the lobster lifecycle. The tags help her track how fast the lobsters are maturing and how far they are traveling.

Slowly, Cowan is amassing a body of knowledge to bring to a debate that she says now relies too much on hunches.

Cowan is as passionate about lobsters as anyone has ever been. But she's not an ideologue or a "treehugger," she says. And she's not particularly interested in weighing in on rules or worst-case scenarios, because they are based on so little information.

Almost everyone agrees human beings don't know much about lobsters, beyond how to steam or bake them. It is difficult to study creatures that dwell in the dark recesses of frigid waters, and few have done so.

The 39-year-old Cowan wants desperately to collect so much data that lobsters will no longer be a mystery. And so, hopefully, there will never be a major crisis in the Gulf of Maine like the mysterious malady that has already devastated lobsters in Long Island Sound.

"One of the things I love about lobstering is that it's individual businessmen fishing a wild animal that roams around free and happy," Cowan said. "I just think there's something philosophically good about that."

Preventing a lobster disaster
It's no surprise that lobsters, the most valued catch in the fishing industry from Maine to North Carolina, are the subject of heated emotions. The crustaceans are essential to life and livelihood in Maine, which produces half of America's yearly lobster catch.

Last year yielded the highest catch on record, at 53.1 million pounds, worth $183 million to fishermen. It's no wonder so many lobstermen contest the contention made by some regulators and scientists that the population is overfished and could crash at any moment.

"We've never seen fisheries persist over the long term when they've been fished at these rates," said Steven Murawski, a biologist at the National Marine Fisheries Service.

Cowan prefers not to make such pronouncements, but a lobster disaster is the last thing she wants to see. So she lives on Friendship Long Island, where the winter population is three, her only power is solar, and she has to haul water 530 paces from a well when the pipes freeze. All to be near the lobsters, and maybe, one day, save them from extinction.

Obsessed since seventh grade
Born in Michigan and schooled in New York state, Cowan became obsessed with lobsters after she chose them for a seventh-grade report. Even back then, high school classmates signed her yearbook to "the lobster lady."

In a Boston University graduate program at the Woods Hole Oceanographic Institution, she stayed up all night to watch the nocturnal crustaceans for eight, 10, even 18 hours. She learned lobsters have complex social behaviors never before catalogued. They build shelters, do housekeeping, groom themselves, and visit each other at night, looking for potential mates.

"It's a regular soap opera," Cowan said. "They're not chimps, but they do some pretty cool things."

(Those cool things do not include "holding hands" on the ocean floor or mating for life, as some animal rights activists have claimed, Cowan said.)

Since graduate school, Cowan has sacrificed career advancement in the name of pure science. She taught for a few years at Bates College and the University of Southern Maine, but found it interfered with her field work when the tides were just right. So for three years, Cowan waitressed at a seafood restaurant that agreed to schedule her shifts around the tides.

"There's more to science than looking at numbers," Cowan said. "There's some intuitive part of it you have to be there for."

In 1996, Cowan founded the Lobster Conservancy, although it was mostly just her and a Web page (lobsters.org). Grants and donations — including the house she lives in — have allowed her to expand and hire a fellow biologist. This year the nonprofit has a $90,000 budget.

Juveniles in the zone
The Conservancy's major project revolves around the most significant discovery of Cowan's career. In 1992, a couple of lobstermen's sons showed her something scientists had never seen: juvenile lobsters, thought to dwell only in deep, inaccessible waters, living in intertidal zones.

Since then, Cowan's lobster tagging project has grown to include more than 50 volunteers working at 24 sites from Isle au Haut, Maine, to Manomet, Mass. They have thus far tagged 10,000 lobsters.

Cowan tags the lobsters with a piece of metal, not much bigger than a grain of sand, that carries six microscopic barcodes. In her monthly visits, she rediscovers about 10 percent of previously tagged lobsters. When she finds one a second time, she snips off the leg with the tag inside, since lobsters can regenerate body parts.

"She's doing amazing work," said Murawski. "It's giving us intimate details about local populations."

Cowan has earned respect from lobstermen as well.

"The fishermen all help her, and they sure wouldn't help her if they didn't like her," said lobsterman and lifelong Friendship resident Henry Thompson.

He doesn't have as many nice things to say, though, about the new laws regulators are passing. "They're really foolish laws," he complains.

Scientists, however, are calling for even stricter rules. A report released by the Atlantic States Marine Fisheries Commission in June recommended increasing the minimum legal size for lobsters and establishing trap-free sanctuaries.

They point out that 95 percent of the lobsters landed are barely over the minimum size, too young to have produced many offspring.

Cowan agrees the pressure on lobsters has been high, that more need to be allowed to grow up. But scientists know so little about the animal, it's impossible to say anything with certainty, she says.

So her immediate goal is to keep tracking juvenile lobsters. To that end, she's readying a lobster pound on the island to watch the lobsters, if it works out, for the rest of her life.

Do ranchers eat beef?
As hard as she works, the biologist has a sense of humor about the creature she has built her life around. In her island home, every refrigerator magnet and most every picture on the wall features a lobster.

Visitors are often surprised, Cowan said, to discover she eats lobster "as often as possible." Some Canadian observers this week were so shocked at the dinner Cowan served they left their steamed lobsters untouched in favor of corn on the cob.

"I think they're delicious. I think it's normal to eat them," Cowan said. "As a human, I'm a predator. They have a much better life than a lot of the things we-eat."