Chesapeake Bay crabbers are likely to face some harvest restriction this season to protect future generations of the crustacean, a move managers say is necessary because of the low population of juveniles.

Fishery managers for Maryland, Virginia and the Potomac River Fisheries Commission all said they are considering shortening the season and imposing stricter bushel limits on female crabs. They are not proposing changes in male crab catches.

News of harvest cuts surprised some crabbers at Maryland’s Blue Crab Industry Advisory Committee in mid-May. The latest winter dredge survey results released in April showed the highest number of female crabs in the 28-year history of the annual count. Female crabs clocked in at 254 million, a 31 percent increase over last year.

But the Baywide survey, which counts the crabs in more than 1,000 locations as they burrow in the mud, estimated there were 125 million juvenile crabs in the Chesapeake, a 54 percent decrease from the 271 million found in 2016. That is the lowest tally since 2013 — a year when crabbers also had their catch curtailed — and one of the five lowest estimates since 1990, managers said.

As a result, managers are expecting a robust harvest for the first half of this year, fueled by the large number of adults now in the Bay. But catches of the Chesapeake’s most valuable seafood will need to be curtailed later in the year to protect the smaller number of juvenile crabs as they reach market size.

Maryland and Virginia are both expected to decide by the end of June on harvest restrictions, which will take effect for the remainder of the 2017 season. The Potomac River Fisheries Commission will discuss its plan at its June 1 meeting, said executive secretary Martin Gary.

Maryland crabbers had expected status quo, at least, based on news reports quoting a DNR press release saying the survey had found the Bay’s crab population “resilient and steady,” with a record number of spawning females.

Instead, Mike Luisi, assistant director of fisheries and boating services with the Maryland DNR, talked at the meeting about returning to limits imposed in 2013, when the season closed on Nov. 10. Last year, the season was extended to Nov. 30.

As with this year’s survey, the 2013 crab canvass showed a robust population of females and low abundance of juveniles, which are 2.4 inches across or smaller yet can be expected to grow to market size by next year. Maryland responded then by tightening bushel limits and shortening the season. The population rebounded enough to relax the limits and extend the season for 2015. If the DNR follows 2013’s lead, the season will close Nov. 10. Many crabbers, depending on their license type, would take between three and seven bushels less. Daily catch limits vary over the season, but last September, for example, they ranged from 19 bushels for a 300-pot license to 35 bushels for a 900-pot one.

Not every crab scientist approves of how management has reacted to the year-over-year changes in the notoriously boom-and-bust blue crab species.

“I am not convinced that we need to change management,” said Thomas Miller, a crab specialist who directs the Chesapeake Biological Laboratory at the University of Maryland Center for Environmental Science. “One of my concerns has been that managers have been too responsive to individual winter dredge survey results. The reference points are meant to be long-term responses of the crab population under constant conditions — and as a result, frequent changes to the management regime makes evaluation of this problematical.”

Though George O’Donnell, the DNR’s liaison to the watermen’s community, said he’d been warning of cuts, most watermen expected better news.

“There’s more crabs than we’ve seen in years,” said Thomas “Bubby” Powley, a Dorchester County trotliner. “They’re telling me they’re not there? The proof is in the pudding,” he said, holding up a smartphone photo of small crabs he had to throw back.

Despite the managers’ admonition that harvest restrictions are needed to sustain the crab population, Powley also asked Luisi and Fisheries Director Dave Blazer to let watermen in their part of the Bay catch more 5-inch male crabs.

Since 2001, the smallest crab that can be caught legally increases in mid-July from 5 inches across to 5.25 inches. The midseason increase was set to give male crabs more time in the water to mate and enhance reproduction. Miller said the seemingly small change in catch regulations helps sustain the Bay’s crab population.

Some Dorchester watermen began pushing two years ago for the ability to catch more 5-inch crabs, which they sell to area picking houses. The department has resisted, and Luisi again said it was unlikely, as the winter survey found male crabs had decreased 16 percent since last year and are only about half what was observed in the early 1990s.

The fight over the 5-inch crab is thought to have cost the DNR’s crab manager, Brenda Davis, her job after 28 years with the department. Davis did not make the decision against relaxing the minimum catchable size; she merely delivered it. But several watermen met with Gov. Larry Hogan Jr. and his deputy chief of staff, Jeannie Haddaway-Riccio, to complain about the restriction and accused Davis of not being flexible enough about the rule. The Hogan administration fired her shortly after the meeting and has refused to give a reason, saying it is a personnel matter.

About half of all crabbing violation citations issued by the Maryland Natural Resources Police are for possession of undersized crabs. It’s by far the most frequent infraction, and growing, according to NRP data, from 185 tickets in 2014 to 302 last year.

Bill Sieling, executive director of the Chesapeake Bay Seafood Industries Association, said he was surprised by the NRP data, contending that the processors he represents only buy small crabs when they’re legal.

“I don’t know where those crabs go,” he said. “Any legitimate dealer in Maryland, you won’t find many violations.”

The Maryland DNR will decide what changes to make in crabbing regulations in consultation with its Tidal Fisheries Advisory Commission. Once the department decides, it will put out a notice for the change, to take effect 48 hours later.

The Virginia Marine Resources Commission will likely make a decision June 27. Commissioner John M. R. Bull said repeating last year’s late closing on Dec. 15 and this year’s early opening on March 1 would not be possible, given the drop in juvenile numbers.

“This year’s babies are next year’s mamas,” Bull said. “We want less of them to be harvested in the fall, so they will be able to be next year’s mamas.”

Also unlikely is the reopening of the winter dredge fishery, where crabbers take pregnant females that are burrowed in the mud. Virginia closed the fishery in 2008 after that year’s survey found the overall crab population at a historic low. Every year since, crabbers have lobbied to reopen it to provide a winter income and allocate the pain of cuts among all sectors. The reopening is on the agenda again for the June meeting; but Bull said the low juvenile numbers “seem to preclude” it.