HOOPERSVILLE -- The workboat Mydra Ann lurches east of this tiny island town, its destination a mile or two offshore in the Honga River near the Chesapeake Bay. Slowly, its rusty chains lower a dredge into the white-capped waves, scraping the bottom nearly 30 feet below for crabs, of any shape and size.
The dredge surfaces a few minutes later, a clamplike device filled with the detritus of the bay's bottom: grapelike sea squirts, dead grasses, clumps of mud and a few oyster shells. State biologists Chris Walstrum and Heather Brown waste no time going for the 16 crabs in the mix, breaking out their metric rulers, their pencils and their graph paper.
"Twenty-six male, 16 female, 18 male, 20 male, 23 female," Brown calls out as Walstrum scrawls down the figures, measurements given in millimeters.
On a typical day, the Mydra Ann's dredge will scrape the bottom about 30 times. By winter's end, it will have done it 750 times.
The boat, rented from a local waterman, is a critical part of the state's annual winter dredge survey, a scientific attempt to count the crabs in the Chesapeake Bay and its rivers. In a few months, when the survey's results are in, the scientists will be able to predict with reasonable certainty what the crab harvest will look like for the 2008 season - a much-awaited forecast since the bay's crab population has declined in recent years.
The results will tell the crabbing industry - a loose coalition of independent watermen, crab processors and pickers that employs thousands of workers in Maryland and Virginia - whether the season that begins April 1 is likely to be a good one.
"It's a hallmark survey. It really gives us the best information," said Lynn Fegley, a director with the Maryland Department of Natural Resources' fisheries service. "The reality is, based on the abundance we measure, we can pretty much determine the harvest for the subsequent year - within 10 or 12 percent."
The survey, now in its 18th year, has produced results fluctuating from a high count of 852 million crabs in the Chesapeake Bay in 1993 to a low of 253 million crabs in 2001. The drop prompted restrictions in both Maryland and Virginia that experts say helped stem a crab decline but did not spur the hoped-for rebound.
Last year's winter dredge survey found the second-lowest number of juvenile crabs since the state began counting in 1989. Those low numbers prompted Fegley to warn watermen last fall that the crabs were in danger of being overfished, and to ask for their help in coming up with a solution.
Fegley expects the department to release harvest data for the 2007 season by the end of this week. And while she said she didn't want to comment until then, she acknowledged that the final numbers "will probably be low."
Looking to next season, "there is a lot of concern right now," she said.
To estimate the bay's crab population, scientists have divided the estuary into 1,500 sites - half in Maryland and the other half in Virginia - to look for crabs that are in the midst of a long winter's nap. Instead of skittering across the bottom, as they do in warm weather, they stay burrowed in the mud, there for the counting.
To Fegley, the Mydra Ann's crew - which includes biologists Brown and Walstrum as well as captain Roger Morris and first mate Bobby Patterson - are true heroes in the efforts to better manage the Chesapeake Bay and its fisheries.
During the past four weeks, they have endured snow, rain, ice and 14-degree temperatures for more than 10 hours a day aboard the open boat, which has barely enough room in the cabin for the captain and his mate.
One morning last week, Morris said, there was ice in the water. Another day, the boat was encrusted in ice. The boat and crew will put up with any type of weather except high winds - if it's blowing more than 35 mph, they will likely cancel.
They take measurements of crabs from the deepest reaches of the shipping channel to the shallower rivers, sometimes extending the chain more than 400 feet to position the dredge at the proper angle.
Sometimes they reach a site and the dredge pulls up only muck and grass; other times, it is full of blue and reddish-hued crabs, apparently too groggy from their rough wake-up call to protest much about being manhandled and measured.
"To do it right is a challenge to me," said Morris, a fifth-generation waterman who lives near Church Creek. "I try to do it right - I know I do it right."
And, he said, the discomfort is worth it to try to gauge a population that is constantly in flux - even if the survey won't guarantee how big a harvest he can expect this year from one of nature's most unpredictable creatures.
"Definitely, last summer was off," he said of his relatively small catch. "I've seen it rebound, and I've seen it slow. I'm not too worried about it."
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