With construction completed at Harris Creek, biologists have proved they can build massive oyster reefs unimaginable a few years ago.

Now, the question is: Can they complete nine more in the next decade to meet the Chesapeake Bay Watershed Agreement goal of restoring oyster populations in 10 tributaries by 2025?

“We now know we can do at least one, and that one was pretty big,” said Stephanie Westby, oyster project coordinator with National Oceanic and Atmospheric Administration Chesapeake Bay Office. “I think it is certainly feasible to get to 10 by 2025. But we are going to need to speed up to some degree to get there.”

Large-scale projects are under way in six other tributaries, but many of those are years away from completion and will absorb much of the available resources — from funding to oyster shell — to complete.

For some of those tributaries, the final restoration size has not been established. No decisions have been made about where the final three projects might take place.

In general, Maryland projects tend to be further ahead than those in Virginia. The Maryland work started with several large designated sanctuaries, and teams were established for each tributary to develop plans and set restoration goals.

“We are missing a lot of that in Virginia,” said Susan Conner, chief of the Environmental Analyses Section of the Army Corps of Engineers Norfolk District. “We don’t have the sanctuary areas designated, so any time we want to construct, we work with the Virginia Marine Resources Commission to identify protected areas where we can construct, but it is not as straightforward as Maryland.”

So, while work began in Harris Creek in 2011, major construction started in Virginia only last year. Nonetheless, the commonwealth’s progress has been jump-started to a degree as biologists have identified two rivers that had been left largely unharvested for decades — the Lynnhaven and Lafeyette — which are approaching restoration status.

Still, substantial obstacles remain to meeting the 10-tributary goal. Oyster restoration is hugely expensive, with projects often costing tens of millions of dollars. Lessons learned from Harris Creek and other projects so far have provided insights on how to ramp up projects and reduce costs — Harris Creek came in at roughly $6 million less than its original $31 million price tag.

But it’s unclear whether past funding levels will continue in the future. The U.S. Army Corps of Engineers, which spends about $5 million a year on Bay oyster restoration, will meet its spending limit within two years unless Congress authorizes additional money.

That funding is especially important for Virginia projects. Unlike Maryland, where the Department of Natural Resources has invested millions in oyster restoration, the VMRC has no funding for such work. Most of its support comes in the form of excavated fossil oyster shell that it donates for restoration projects.

“We wish we could do a lot more, but that is what we can do, and we are pleased to do it,” said Laurie Naismith, a spokeswoman for the commission. “We appreciate everything the Corps is doing on that, but we do not have the budget that is necessary to complete a project that is that large.”

Virginia projects tend to be less costly, though. Because of its higher salinities, restoration sites can usually count on receiving natural spat sets from nearby reefs, so they don’t have to put money into planting hatchery-reared oyster spat, which is essential in Maryland. In Maryland, projects have to rely on a single hatchery at the Horn Point Lab, which also produces spat for aquaculture and other purposes, and cannot always meet restoration demand.

Another impediment is public support.

While oyster reefs are popular with biologists and environmental groups, the large-scale projects have brought opposition from others, including boaters worried that reefs could affect navigation, and particularly from watermen who were already angered that the sanctuaries used for restoration shut them out of areas that had traditionally been harvested.

The Dorchester County Council last year opposed any additional work on the Little Choptank, contending its designation as an oyster sanctuary was hurting watermen and expressing skepticism that the project would succeed. “When federal and state agencies approve permits and programs that deprive the citizens of the county of fishery resources on which their social, economic and cultural livelihood are dependent, such agencies and such action cripples the human environment of the county,” the council said.

Finding suitable — and acceptable — material as reef substrate has been difficult. Watermen have objected to the use of material such as granite in Maryland tributaries, contending it interferes with crabbing and other fishing gear.

The supply of oyster shell for reefs is very limited, and its cost is growing as restoration projects face competition from the growing aquaculture industry for the remaining supply. The Maryland DNR even began importing fossil shell from Florida to meet demand for oyster shells in Harris Creek and the Little Choptank.

And in both states, the lure of vibrant oyster reefs also raises concern about attracting poachers. Officials say Harris Creek has already suffered some poaching, and in Virginia, biologists say a large restoration project on the Great Wicomico was also set back by illegal harvests.

In Maryland, the DNR is employing new high-tech methods to monitor reefs and prevent poaching, and in Virginia the General Assembly this year changed the law to allow the VMRC to revoke fishing licenses for up to 5 years and levy fines of up to $10,000 on poachers — something it has already begun enforcing.

Besides Harris Creek, here are other tributaries with large-scale restoration projects:

  • Tred Avon, MD: The Corps began working in this Choptank River tributary last winter, when 16 acres of reef were built. Another 8 acres are expected to go in this winter. During the winters of 2017–20, the Corps hopes to construct 59 more acres. The project will restore about 185 acres.
  • Little Choptank, MD: The Maryland DNR constructed 95 acres of reef last year that was to be seeded with oyster spat this year, and oyster seed was planted on 17 additional acres that did not require construction. A permit application for an additional 169 acres of reef construction is pending. The project is expected to total 440 acres of restoration.
  • Lynnhaven River, VA: The river has about 63 acres of sanctuary reefs, many of which recovered when the river was left unfishable for decades because of water pollution. Additional acres, including a number of projects completed by nonprofit groups such as Lynnhaven River NOW and the Chesapeake Bay Foundation, also exist but have not been quantified to determine whether they meet restoration thresholds. “We feel there is a lot out there that has not yet been monitored and captured,” Conner said. The final restoration target for the river has not been finalized, but is expected to be 90–200 acres. The Corps, in the next couple of years, plans to launch a major large-scale ecosystem restoration project in the Lynnhaven, which would include not only oysters, but other important habitats such as seagrasses. “If we have not met our goals by that time, that Lynnhaven ecosystem restoration project would construct enough hard reef habitat for it to be a fully restored tributary,” Conner said.
  • Lafayette River, VA: The Lafayette, a tributary to the Elizabeth River, is an urban waterway that has been off-limits to harvesting for decades — its oysters are unsafe to eat because of pollution. But scientists were pleasantly surprised during surveys to find 50–60 acres of functioning reefs that have built up since harvest was closed decades ago. A number of other reefs have been built over time by the Elizabeth River Project, Chesapeake Bay Foundation, or as mitigation projects. That could bring the number of reef acres to near 70. A final restoration goal has not been set for the Lafayette, but Conner said it would likely be less than 100 acres. “It is a tributary that could be near success.” Though not technically a sanctuary, the VMRC has taken action to ensure that the restored reefs would not be leased for harvest as the river is cleaned up.
  • Great Wicomico, VA: The Corps supported the construction of 83 acres of sanctuary reefs in 2004, and recent monitoring found that oyster populations were meeting restoration goals on 61 acres. Those not meeting goals were built lower to the ground, or had been poached. This year, the Corps supported work to rehabilitate about 15 acres that were not meeting goals. The Corps’ master plan calls for at least 100 acres of oyster restoration in the river.
  • Piankatank, VA: The Nature Conservancy and the VMRC built a 21-acre sanctuary reef in the Piankatank last year and another 3-acre reef this year. The Corps is planning to build another 20–40 acres over the next two years. The Corps’ original restoration master plan for the river had identified a restoration goal of 700–1,300 acres, but “the tributary planning team has been narrowing that down,” Conner said. “So I think it will be less than that, but we just don’t know how much less.”