Shaun Miller, a biologist with the Maryland Department of Natural Resources measures blue crabs from the Chesapeake Bay. Photo by Joel McCord/WYPR.

Every year about this time, crews from Maryland’s and Virginia’s natural resources departments head out onto the Chesapeake Bay and its tributaries on boats. Workers are dredging the muddy bottom in the water for crabs, not for the steamer, but for research. It’s called the winter dredge survey. State employees use the information they get to develop harvest regulations for commercial crabbers.

Shaun Miller, a biologist with Maryland’s Department of Natural Resources, says they have to do it in the winter because that’s when crabs hibernate, when they “bury themselves in the mud.”

Miller said that winter is ideal because, “this is the only time of the year that they’re not mobile,” he explained. “If we tried to do the same thing and get an estimate during the summertime, it’d be impossible.”

Genine McClair, who runs the Maryland Department of Natural Resource’s blue crab program, says the survey is the first of three steps. They use the results to develop a management program and then they do research.

“And that’s really just us partnering with academic institutions or other scientists in the region to identify knowledge gaps when it comes to blue crabs and help to fill those knowledge gaps,” McClair said.

On a recent gray January morning, they were working a section of the upper Chesapeake Bay off Rock Hall on the Eastern Shore.

Capt. Roger Morris, a Dorchester County waterman who works under contract with the state’s department of natural resources, dropped a Virginia dredge off the stern of Mydra Ann, his 45-foot Bay workboat, and let the attached chain pay out until the dredge hit bottom 20-some feet below, jolting the boat. A Virginia dredge refers to an eight foot wide piece of equipment with an attached net that gets dropped into the water to dredge for crabs. Morris eased the throttle forward and dragged the dredge through the mud for one minute at three knots, then hauled it back up, pausing to rinse the mud out before bringing it on board.

McClair and John Murphy, Morris’s crewman, flip the net to empty it onto a wide wooden platform and begin sorting on their hands and knees through an array of shells, searching for blue crabs. Nothing.

But it’s only the first stop on a trip that will take them from the Eastern to Western shore, off the mouths of the Patapsco and Magothy rivers and back to Kent Narrows, about 45 miles southeast of Baltimore’s Inner Harbor, by the end of the day.

Read more at WYPR.