Scientists say they have only a vague idea of how many oysters cover the reefs in the Chesapeake Bay, and can't say how many can be harvested safely each year without threatening the future of an already decimated population.
Over the next year and a half, they hope to figure it out.
In the waning hours of its 2016 session, the General Assembly authorized a study that advocates say will not only provide a more precise count of the bivalves, but assess how quickly they are reproducing, how fast they are growing and how they are faring against disease.
Such research is already conducted on other key creatures of the Chesapeake, including blue crabs and rockfish.
The oyster study stoked controversy in an hours-long hearing earlier this month. Many watermen said it would lead inevitably to restrictions on their harvests, and the state Department of Natural Resources initially opposed it because the legislation left the DNR out of the research.
But in a compromise, lawmakers gave the department responsibility for the study, to be conducted by researchers at the University of Maryland Center for Environmental Science. A final report is due in December 2018.
"It's not going to be quick and it's not going to be easy, but it means [oysters are] going to be treated like every other fishery in the Chesapeake Bay," said Del. Kumar Barve, a Montgomery County Democrat who helped negotiate revisions to the bill. "Our objective is to have a sustainable oyster harvest and a successful oyster-producing industry."
Mark Belton, secretary of the state's Natural Resources Department, called the legislation "a reasonable compromise for conservationists, environmentalists, the public and watermen."
The department already conducts surveys each fall to determine how often oyster larvae are attaching successfully onto reefs and to estimate a rough size and weight of the oyster population. But Belton said officials welcome the more intensive stock survey.
"We believe this new study will assist the department's ongoing efforts to effectively manage the species, and complement our previously planned oyster reports, surveys and studies," he said in a statement.
The Chesapeake's oyster population, devastated by disease, pollution and overfishing, is believed to have fallen to about 1 percent of historical levels. The state's most recent study, from fall 2014, showed oyster larvae, known as spat, were attaching to beds at their lowest rate since 2005 (but an index of oyster biomass in the bay was close to the previous year's record high.)
The new study will gather information on oyster reproduction, growth and mortality rates to predict how many oysters might be in the bay in coming years, said Donald Boesch, president of the University of Maryland center.
Similar assessments were used to develop policy on crab harvests, and have been credited with helping the crustaceans' numbers to grow in recent years.
The Chesapeake Bay Foundation sees the study as "a significant step forward in how we manage the oyster fisheries," said Alison Prost, executive director of the group's Maryland office.
Watermen are fearful of changes the study might bring.
Bunky Chance, president of the Talbot County Watermen's Association, said there are enough oyster surveys being conducted, and it's unclear what the new study will add.
Robert T. Brown, president of the Maryland Watermen's Association, said watermen fear the University of Maryland researchers want eventually to impose an outright moratorium on oyster harvesting.
That would be one more hardship for a beleaguered industry, Brown said.
"If our oyster industry gets hampered a whole lot in the wintertime, there is nothing else for our watermen to do," he said.
Boesch said researchers aim to gather facts to inform discussions about oyster harvesting.
The study is the latest point of controversy over the state's oyster population. In December, state officials asked the Army Corps of Engineers to pause an oyster restoration project in the Tred Avon River. They said they wanted to evaluate how well it was working before spending more money.
Watermen had protested that project, saying it wasn't effective. When the Army Corps said in January it was diverting $1 million from Maryland to projects in Virginia, conservation groups criticized the decision.
Barve said that conflict wasn't a factor in the compromise.
"This is about a sustainable oyster harvest," he said. "There's a lot of angst there, but that certainly wasn't our motivation."