Four more Chesapeake Bay tributaries have been chosen for large-scale oyster restoration efforts — if and when money becomes available.Under the federal-state Bay Watershed Agreement signed nearly four years ago, Maryland and Virginia have each pledged to restore oyster populations in five of their tributaries by 2025. (Dave Harp)

In Maryland, Natural Resources Secretary Mark Belton announced in mid-December that he’s recommending two Potomac River tributaries — Breton Bay and the upper St. Mary’s River — as the fourth and fifth Chesapeake tributaries where the state would work with federal agencies to try to restore oyster populations. 

In Virginia, state and federal officials have selected the Great Wicomico and the Lower York rivers as the next two tributaries in that part of the Bay to be the focus of restoration efforts.

The Maryland announcement comes after more than a year of debate and deliberation over where the state should next direct its restoration efforts. Both Breton Bay and St. Mary’s River are in St. Mary’s County, across the Chesapeake from three waterways already undergoing restoration — Harris Creek and the Tred Avon and Little Choptank rivers.

Under the federal-state Bay Watershed Agreement signed nearly four years ago, Maryland and Virginia have each pledged to restore oyster populations in five of their tributaries by 2025. The selections announced recently move both states toward fulfilling their commitments.

The Maryland choices did not come without rancor. Watermen have criticized the $28 million price tag and effectiveness of the completed restoration in Harris Creek. Surveys indicate oysters planted on constructed reefs there are surviving and attracting new generations of bivalves. Nevertheless, watermen — who have long chafed over the 2010 expansion of Maryland’s oyster sanctuaries — have complained and succeeded in delaying or shrinking restoration projects still under way in the other two Eastern Shore rivers.

Belton said he chose to recommend Breton Bay and the upper St. Mary’s because both ranked near the top when he asked members of the DNR’s Oyster Advisory Commission, which included watermen, where they’d like to next see restoration. Surveys must still be done to assess their suitability, and how much of their bottom is considered restorable.

A 2016 DNR report found the upper St. Mary’s River had the highest natural “spatfall,” or reproduction, of any water body in Maryland, and that oysters had grown in size in the 1,300-acre upper river area since it was designated as a sanctuary.

But Southern Maryland watermen had opposed the selection of the St. Mary’s River, the upper portion of which was closed to them in 2010 when it became a sanctuary. The river once yielded a substantial harvest, but not since MSX and Dermo, two oyster diseases, swept up the Bay in the late 1980s.

Belton’s other pick, Breton Bay, garnered the most support among advisory commission members — and the least opposition — but DNR biologists in their 2016 review found that the oyster population in the sanctuary there was only slightly above average, while natural reproduction had historically been “low and intermittent.”

The Chesapeake Bay Foundation welcomed Belton’s selection of the St. Mary’s River, but criticized Breton Bay. Alison Prost, Maryland executive director, said the upper St. Mary’s “is likely capable of developing a self-sustaining oyster population, and could act as a nursery for downstream areas where oysters can be harvested, as long as the upper river remains a sanctuary area off-limits to harvesting.”

But Prost said Breton Bay appeared to be a poor choice for restoration, calling it “a low-salinity area with a history of low oyster reproduction.” She predicted that achieving success there would be “difficult and expensive.”

The Virginia selections also come after lengthy review by an interagency team of federal and state officials, plus scientists and representatives of nonprofit groups. There has been no similar pushback from watermen there, said Susan Conner, policy and planning chief of the Norfolk District of the U.S. Army Corps of Engineers, which has spearheaded much of the large-scale reef construction in Virginia.

The Great Wicomico and Lower York join a trio of Virginia rivers already undergoing restoration — the Lafayette, Lynnhaven and Piankatank. None is finished, though the Lafayette is nearly so, with five acres of reefs still to be built to reach its goal of 80 acres of refurbished oyster habitat.

The Great Wicomico underwent some restoration earlier, with about 85 acres of reefs constructed in 2004. Some of that failed to sustain oysters, and some of the rest got poached, but it has since been rehabilitated, Connor said. About 61 acres are now considered successfully restored, with a self-sustaining oyster population.

“We have a lot of good reconstruction sites defined there,” Conner added, leading officials to believe that restoring its oyster population on a larger scale is “within reach.”

The lower York River was chosen, in part, because the Navy has expressed interest in participating there, as surveys show substantial reefs already along the shore near Naval Weapons Station Yorktown. Also working in that river’s favor, Connor said, is the presence of the Virginia Institute of Marine Science, a research reserve and restoration activity by the nonprofit Chesapeake Bay Foundation.

The Eastern Branch of the Elizabeth River in Norfolk also was considered, Conner said. But the Virginia Marine Resources Commission, the Corps’ major partner in the restoration work, wasn’t interested in doing large-scale reef-building there, Conner said, and the interagency group decided to look to other parts of the Bay. The Elizabeth River Project and other nonprofit groups have done some smaller reef projects in the river, she said, and they intend to continue that effort.

It’s unclear when, or if, there’ll be money to conduct more large-scale restoration work in either Maryland or Virginia. Congress had been providing about $5 million annually, to be split between the states for such projects, but that funding has not been renewed the last two years, Conner said. The Norfolk District built a 25-acre sanctuary reef last year in the Piankatank at a cost of $2 million, but that’s about all that can be done until more money is forthcoming, she said.

“We would like to be funded,” Conner said, “but we are at the mercy of Congress in providing that funding.