CAMBRIDGE — Two years after Maryland and Virginia implemented major restrictions on crab harvesting, the Chesapeake Bay’s crab population has more than doubled. Now state officials hope an oyster hatchery, combined with new oyster sanctuaries, can help bring that population back from the brink.
In 2008, Maryland restricted the number of female crabs that could be taken from the bay and implemented other changes to reduce the female crab harvest by a third. Watermen were not happy about the severe restrictions, arguing they were misdirected.
Mike Naylor, director of the Department of Natural Resources’ Shellfish Program, said people acted like the restrictions were the “end of the world.” But the adult crab population nearly doubled the next year, and the overall population this year reached its highest point since 1997.
“We hope that the oyster population will respond in a similar way,” Naylor said.
The oyster population has been in bumpy decline for decades, with harvest numbers bottoming out at 26,471 bushels in the 2004 oyster season, according to DNR data. Last year’s oyster harvest — 101,141 bushels — is still only about 1 percent of the harvests in the late 1800s.
But the significant harvest restrictions that seem to have worked for the crab population won’t work for oysters, Naylor said.
“Fishing pressure is not the limiting factor,” he said. “Oysters are limited by disease.”
Instead of simply limiting oyster harvesting, the state wants to increase oyster sanctuary areas — so some disease-resistant oysters have more chances to reproduce — while increasing oyster production at the University of Maryland Center for Environmental Science’s Horn Point Laboratory.
The lab produced 750 million baby oysters last year, and oyster hatchery director Don Meritt said he hopes a new pier will soon help them produce 1 billion to 2 billion a year.
The Horn Point hatchery is not trying to “take the place of Mother Nature,” Meritt said, but rather to “jump-start Mother Nature” in certain areas.
“There’s no way this hatchery, as large as it is, could equal the output of what the Chesapeake Bay used to be 100 years ago,” Meritt said. “But by targeting special places, we can help bring it back one tributary or sub-tributary at a time.”
Naylor said the baby oysters grown by the hatchery are placed in parts of the bay that were productive oyster habitats as recently as the 1980s, but now have no oysters at all.
Three general problems caused the decline in oyster population, Meritt said: a century of overharvesting, habitat destruction and disease.
The hatchery is part of a program working to develop disease-resistant oysters, but different areas have different disease conditions, so there can’t be a one-size-fits-all approach, he said.
Gov. Martin O’Malley has proposed an Oyster Restoration and Aquaculture Development Plan that focuses on increasing oyster sanctuaries and encouraging more commercial aquaculture to rebuild the oyster population. But the plan has met with resistance from watermen, who traveled to Annapolis several times during the recently completed legislative session to support bills that would negate parts of it.
The bills failed, but Naylor said the department is working with watermen to come to a compromise on the areas that will be set aside as oyster sanctuaries.
The plan was originally scheduled to be adopted in May, but will be delayed while discussions continue. Naylor hopes to have the regulations adopted by the beginning of the oyster season in October.
Watermen have argued that sanctuaries have not been successful and that the state overemphasizes the impact of poachers. But Meritt said poaching is a huge problem in sanctuaries.
“Almost none of the [sanctuary] sites are left alone. So the ones that are supposed to be sanctuaries, are supposed to be closed … rarely are kept closed,” he said. “[That] really makes it difficult to analyze how successful a project was, when someone comes in and steals a lot of it before the project is completed.”
When O’Malley announced the surge in the crab population, Chesapeake Bay Foundation President Will Baker said it showed that “the bay can be saved” using science-based policies.
Meritt agreed that science-based management techniques have made a difference — at least in the short term — for rockfish and crabs, and can work for oysters, too.
In the 2008-2009 oyster season, watermen harvested a little more than 101,000 bushels of oysters. Meritt said a well-managed acre can produce 1,000 bushels of oysters a year. Oysters take about three years to grow to harvestable size, but even so, last year’s harvest could be maintained with less than 1,000 acres of good aquaculture — in a bay that historically had 200,000 acres of oyster habitat, Meritt said.
“We believe it’s possible to grow a lot more oysters in Maryland using farming techniques than we have in the past with the public fishery,” he said. “Chesapeake Bay oyster grounds are not very productive, and they can be.”