Biologist Chris Walstrum (left) logs statistics while biologist Joe Williams weighs a crab.
Biologist Chris Walstrum (left) logs statistics while biologist Joe Williams weighs a crab. (Candus Thomson, Baltimore Sun)

— A mesh net tips onto the stern of the work boat "Mydra Ann," and out tumbles a community of crabs: fist-size blues with claws raised in attack mode, tan adolescents trying to scuttle for cover and translucent babies no bigger than a thumbnail.

Picking through the pile, state biologists conduct their census, measuring and weighing each Chesapeake Bay resident before returning it to the ice-cold water and several more weeks of hibernation.

"There's a lot of little crabs out there. I feel good about that," says Roger Morris, a waterman for more than 30 years who helps the Department of Natural Resources conduct its annual winter dredge survey.

Results of the survey are eagerly awaited each spring by watermen, recreational crabbers and folks who consider steaming and picking a dozen or two a rite of summer.

From Dec. 15 until the end of February, Maryland biologists sample a total of 750 sites from Pooles Island near Baltimore to the state line to determine the number of adult crabs, newcomers and potential spawning females. Their counterparts in Virginia do the same from the state line, south. Then in March, they sample again to see how many crabs succumbed to winter weather. From those estimates, fisheries managers determine the health of the population and set regulations.

"This is the most accurate estimate we have for the crab population," says biologist Chris Walstrum as he logs the results from the net.

Conducting the survey is labor intensive. The work boat drags a metal basket lined with a nylon net along the bay bottom. Slumbering crabs — accompanied by lots of shells, sticks, mud and debris — are lifted onto the deck and shaken free. Then the counting begins.

While everyone awaits the numbers in April, biologists are careful not to raise or dash hopes. Mum's the word.

Still, Lynn Fegley, a Maryland Fisheries Service manager, smiles at a reporter's leading question.

"There's no indications from the field that we're going to see anything unusual," she said. "The problem with crabs is that they're pretty variable critters, so you never know."

It doesn't take a long memory to recall how one year's triumph can become the next year's disappointment.

In 2008, overfishing pushed the population so low that the U.S. Commerce Department declared the Chesapeake Bay's blue crab fishery a federal disaster. Maryland and Virginia officials agreed to reduce the harvest of female crabs by one-third to protect female crabs and restore the spawning stock.

Their conservation efforts were rewarded in 2010 with a population explosion. The estimate of 658 million crabs was more than double the total in 2008 and gave officials cover against attacks by some commercial interests.

The good news caught the public's eye. The Department of Natural Resources sold 53,477 recreational licenses in 2010, an increase of nearly 10 percent and the highest number in a decade. Tackle shop owners said they sold more gear and bait.

But a harsh winter and low bay temperatures last year battered the population. About 31 percent of Maryland's adult crabs died, compared with 11 percent in 2010. Even with that setback, the population was 460 million crabs, the second-highest level since 1997.

The announcement of the population by the governors of Maryland and Virginia was upbeat but with a healthy degree of caution.

A new scientific assessment last August shifted the focus from overall population to the health of the female stock. It set a sustainability benchmark of 215 million females, with overfishing occurring if 34 percent of the females are harvested in a year. A month later, the Virginia Marine Resources Commission voted unanimously to continue for the fourth year its ban on winter dredging by watermen.

Back on the "Mydra Ann," the biologists finish their work and begin packing their gear away as Morris turns his boat toward shore. His weathered face sports a grin as he talks about the coming season.

"Crabs, the Orioles, sunny days and warm evenings," he says. "In Maryland, that's good living."