The record for the world’s largest oyster restoration project is poised to be broken with a new $30 million project on Maryland’s Eastern Shore, but some environmentalists would like it to be even bigger.
At 441 acres, the amount of restored area on the bottom of the Manokin River in Somerset County would be the most ever undertaken by the state. With no projects being completed on that scale anywhere else, it would also claim the world’s title.
The river that currently holds that designation is the Little Choptank River in Dorchester County. The initial round of “seeding” of its 358 acres of oyster reefs was completed earlier this year.
The Department of Natural Resources had planned to begin planting baby oysters on the Manokin’s existing reefs this summer. But a backlog of restoration work caused by 2018’s heavy rains, then the COVID-19 pandemic, postponed those efforts until late spring or early summer next year.
The project may turn out to be not only the state’s largest, but also the quickest, officials say.
Under a federal agreement tied to the Chesapeake Bay cleanup, Maryland and Virginia have vowed to replenish oyster reefs in five rivers each by 2025. In June 2019, the Manokin became the last restoration site in either state to be approved by the state-federal Bay program.
“We’re going to have to undertake an aggressive schedule to do it because we have less time than the other tributaries,” said Chris Judy, chief of DNR’s shellfish division.
As they embark on the project’s final design stages, Judy and his colleagues are navigating a narrow path. On one side are watermen who worry that the project will fortify an existing ban on commercial harvesting in the river. On the other are environmentalists who contend the restoration area should be expanded beyond what is currently planned.
“In a river that’s so much larger and had 11,000 acres of oyster habitat in the past, let’s make sure the scale that this is happening on is large enough to make that ecological change,” said Allison Colden, a Maryland fisheries scientist with the Chesapeake Bay Foundation.
Oyster bars once dominated the Bay, covering nearly a half-million acres of its bottom as late as the 1800s. But overharvesting, disease and deteriorating water quality caused the bivalve’s population to fall to 1% or less of its historic levels.
Maryland and Virginia are both on track to restore more than 2,000 acres of oyster habitat in the 10 rivers.
For a reef to be considered fully restored, the density of oysters must be at least 15 per square meter, roughly the area of a bath towel, across at least 30% of the reef’s total surface. The preferred “target,” though, is 50 oysters. Those assessments are conducted six years after the restoration occurred.
State biologists use a formula to calculate how much of a river’s bottom should be restored based, in part, on the historic breadth of its oyster reefs. The formula calls for restoring at least 8% of that acreage, or 401 acres, in the Manokin. The state added a 10% buffer to that amount — in case some areas aren’t up to snuff — bringing the restoration goal to the 441 acres.
Sonar surveys and patent tong tests indicate that as much as 637 acres of bottom would be suitable for restoration. But according to Maryland’s plan for rehabilitating the oyster population in the Manokin, the state lacks the time and resources to restore that amount by the 2025 deadline.
DNR officials say that some waters will be bypassed for practical reasons. Among them: those inhabited by underwater grass meadows, under docks, covered by aquaculture leases or are in or near the boat channel leading to the community of Rumbley.
The Bay Foundation has long pushed for oyster restoration in the Manokin. The river flows from headwaters near Princess Anne into the Chesapeake Bay on the northern end of Tangier Sound.
After the Manokin was made a sanctuary and closed to oyster harvests in 2010, its oyster population reached a 20-year high in 2015. Meanwhile, the number of diseased specimens dropped by more than half, according to a Bay Foundation analysis of state survey data.
“That shows us it has tremendous potential for oyster restoration,” Colden said.
She argues that the state should build in a bigger buffer than the 10% called for in the plan. Two Maryland tributaries have had their restoration acreage slashed after the initial planning phase: the Little Choptank’s by 22% and the Tred Avon’s by 15%. If such a portion is purged from the Manokin, the total would fall below the minimum set by the federal agreement, Colden said.
Watermen strongly opposed the state’s decision to classify the Manokin as an oyster sanctuary. The move put some of the state’s most productive oystering grounds off-limits to commercial dredges. The restoration project will only bolster arguments to make the sanctuary status permanent, they say.
“We’re going to lose the river,” said Gregory Price, co-chairman of the Somerset County Oyster Committee and a longtime waterman. “It’s something that belongs to us, and we want to keep it.”
But watermen have a ray of hope. Because the U.S. Army Corps of Engineers hasn’t contributed funding to the Manokin project, the state alone can decide whether to reopen the oyster grounds. It remains protected from harvest by state law for now.
In addition to the Manokin, Little Choptank and Tred Avon, Maryland is restoring oysters in Harris Creek in Talbot County and the Upper St. Mary’s River in St. Mary’s County, the lone Western Shore tributary included in the plan.
The second phase of seeding has been completed in Harris Creek. Seeding and reef construction continue in the Tred Avon. The Upper St. Mary’s, like the Manokin, is scheduled to get its first round of seeding next year.
In the Manokin, seeding and construction are set to take place 2021–22, Judy said. If necessary, a second round of building will be conducted three years later in 2025. That would meet the deadline, barring any further delays.
By Jeremy Cox