It took a last-minute compromise, but Maryland is finally on track to get a scientific assessment of how many oysters can be harvested sustainably from its portion of the Chesapeake Bay without endangering the ecologically vital shellfish population.

The state’s General Assembly approved a bill in the waning hours of its 90-day session that tasks the Department of Natural Resources with conducting an assessment of the state’s wild oyster stock to determine if harvests are within safe parameters. The DNR must work with the University of Maryland Center for Environmental Science and subject its findings to peer review by independent researchers.

The oyster study bill proved to be one of the more controversial environmental bills adopted during the session, which ended at midnight on April 11. The state’s watermen packed a House hearing the week before to oppose the measure, arguing it was unnecessary and a potential threat to their livelihood.

“We truly believe this is a poison pill that could change the oyster industry forever,” Bill Kilinski, a Charles County waterman, told lawmakers, as an overflow crowd of watermen watched the hearing by video hookup from a neighboring room.

But environmentalists and recreational fishing groups supported the study, contending that harvest levels need to be examined because oysters are a “keystone” species in the Bay with their immense water filtering capacity and the habitat their reefs provide for fish and crabs.

Once so abundant that watermen routinely harvested millions of bushels a year, the Bay’s oysters have been badly depleted since the late 1800s by historical overharvesting, habitat loss and disease. For the past decade or so, scientists have estimated the population is hovering around 1 percent or even less of its historic levels.

Oyster harvests have recently been on the rebound, reaching 400,000 bushels in Maryland the last couple of years. But environmentalists and recreational fishing groups argued that the boost in the state’s seafood industry could be short-lived because no one really knows the size of the oyster population.

The fishery is heavily regulated, with daily catch limits, gear and time-of-day restrictions, and a six-month season that ends March 31. Despite being required to by state law, the DNR has never developed a scientifically based estimate of how many oysters there are and how many are lost each year to all causes. Study supporters say those data are needed to ensure that harvests aren’t threatening the bivalves’ continued survival.

As originally introduced, the bill would have required the UM environmental science center to do the stock assessment, and would have barred the DNR from doing anything to increase harvests until the study was complete. The measure’s Senate sponsor, Montgomery County Democrat Roger Manno, dropped the harvest provision after the DNR objected, and it overwhelmingly passed that chamber. Manno said that Natural Resources Secretary Mark Belton had told him in person and on the phone that the agency no longer opposed it.

But watermen complained to House lawmakers that UMCES couldn’t be trusted to conduct an impartial oyster study, contending that its scientists have previously called for a moratorium on harvests. And a DNR spokeswoman showed up at the House hearing to say the department still objected to the measure, saying without explanation that it would hamper the state’s ability to manage the oyster harvest.

Manno originally objected to having the DNR do the study, saying that by siding with watermen on this and other oyster issues, the Hogan administration had called into question its impartiality.

With days to go, lawmakers hammered out a compromise, giving primary responsibility for the study to the DNR, with UMCES assisting. The measure passed overwhelmingly after that.

The bill would require the DNR to issue a final report by Dec. 1, 2018, with two interim reports before that. And if it concludes that the wild oyster stock is being overharvested, the DNR is directed to publicly collaborate with the commercial oyster industry, conservation groups and “other concerned stakeholders” to come up with any changes in catch regulations.

The Coastal Conservation Association of Maryland, which had argued that oysters are important to everyone, not just watermen, praised the final measure as a “pragmatic solution.”

And Alison Prost, Maryland director of the Chesapeake Bay Foundation, said she considered the compromise a “huge win” because it requires the DNR to subject its findings to outside experts before publishing them.

“Less important to who does the study is the fact there will be peer review,” Prost said.

A spokesman for the DNR secretary issued a statement supporting the bill after it passed, calling it “a reasonable compromise for conservationists, environmentalists, the public and watermen.”

Robert T. Brown Sr., president of the Maryland Watermen’s Association, said his members remained “very leery,” fearing such a study could lead to a catch quota or some other restrictions.

“If the oyster industry gets curtailed, then the watermen have no other industry to turn to during the winter,” Brown said.

But Del. Kumar Barve, chairman of the House Environment and Transportation Committee, which negotiated the deal, called it “a giant step forward.”

“Basically, we’re knocking all their heads together, and we’re going to get the stock assessment,” said Barve, a Montgomery County Democrat. “It’s long overdue, and I’m happy we were able to do it in a bipartisan manner.”

Maryland General Assembly Highlights

Other environmental bills passed include:

  • Greenhouse Gas Reduction Act: Already signed by Gov. Larry Hogan, it commits Maryland to reducing climate-altering emissions 40 percent from 2006 levels by 2030. The new law builds on a 2009 statute that had pledged a 25 percent cut by 2020.
  • Clean Energy: It increases the share of electricity supplied in the state that must come from renewable sources, from 20 percent by 2022 to 25 percent by 2020.
  • Land Preservation: Also signed by Gov. Hogan, it restores tens of millions in funding taken from Maryland’s Program Open Space, which since 1969 has had a dedicated stream of revenue from property sales to acquire parkland and preserve farmland. The law also requires repayment within three years of any future diversions.
  • Pollinator Protection: If signed into law, it would ban Maryland consumers from using pesticides that have been implicated in honeybee die-offs. The pesticides, containing a class of chemicals called neonicotinoids, are widely used, especially in protecting farm crops. As passed, the measure exempts agricultural uses, but it was still opposed by farm groups and the Maryland Department of Agriculture.

Among the environmental bills that failed:

  • Poultry Litter Management: This bill backed by environmental groups, which would have made poultry companies responsible for their birds’ manure, failed to get out of committee. Supporters said it would help farmers who might be unable to use or sell the phosphorus-rich chicken waste under new regulations aimed at preventing the overapplication of that nutrient on farm fields. But growers, the industry and the Hogan administration opposed the bill, calling it premature.