Report positive on oyster restoration
EASTON — People interested in the oyster restoration work in the Choptank River complex can check out a report released this month by the Maryland Oyster Restoration Interagency Workgroup that details the effort’s progress.
In Harris Creek, which was the center of a controversy over the effectiveness of oyster sanctuaries, the report indicates oysters are meeting target numbers for success.
Since work started to build oyster sanctuaries in the Choptank River complex in 2011, nearly 400 acres of oyster restoration has been completed, with about 118 acres that await seeding or are partly seeded, according to the report.
A total of 2.3 billion oysters, the vast majority of which were grown by the University of Maryland Center for Environmental Sciences Horn Point Laboratory in Cambridge, have been planted, the report reads.
Oyster restoration is being targeted in three parts of the Choptank River complex — Harris Creek, the Little Choptank River and the Tred Avon River.
While there are multiple factors that determine whether an oyster reef has been restored, Stephanie Westby, an oyster coordinator and environmental engineer with the National Oceanic and Atmospheric Administration, said “probably the one that is most intuitive and people are most interested in is how many oysters are living” on the reefs.
Harris Creek is where restoration work began in 2011. The last oyster spat on shell were planted in 2015. Westby said 2015 was the first year that 100 acres of reefs in Harris Creek were old enough to be considered for their first check in.
While a full report is due later in 2016, preliminary analysis of Harris Creek shows that all of the reefs seeded in 2012 currently meet an established threshold for success.
The minimum threshold of 15 oysters per square meter has been met over 30 percent of the bottom monitored in Harris Creek, and 50 percent meets a higher target — 50 oysters per square meter. Westby called that the “gold standard” and ultimate high target for oyster restoration.
“We are really pleased with what we’re seeing as of this first three-year check in for those first 100 acres,” Westby said.
Preliminary data also shows there are three times more oysters on stone substrate reef planted in 2013 than on any reef site monitored in Harris Creek, according to the report.
Monitoring work in Harris Creek is planned through 2021 to determine whether the reefs there meet preestablished success criteria, the report states.
In the Little Choptank River, the restoration plan calls for restoring 440 acres of reef with 1.9 billion seed oysters. Of the 440 acres, 40 acres already meet the definition of a restored reef due to natural reproduction. They might not require any restoration, but will be monitored. So far, about 46 acres have been restored, and 102.6 acres of constructed reef are either partially seeded or awaiting seeding.
In the Tred Avon River, 147 acres are slated for restoration. In-water restoration work began in 2015, when the U.S. Army Corps of Engineers built 16 acres of a planned 24-acre project in the river. More than 2 acres are completely constructed and seeded, and 16 are awaiting seeding or partially awaiting seeding.
But, both the Tred Avon and Little Choptank rivers’ construction are hung up due to concerns voiced by those in the commercial oyster industry.
In the Little Choptank River, the DNR applied for a permit to place reef substrate, fossil on shell from Florida, mixed rock and rock, on another 187 acres of reefs. But, the permit application has been temporarily suspended at the DNR’s request to allow time to evaluate the watermen’s concern.
When work started in the Little Choptank River with the fossil shell from Florida in 2014, Dorchester watermen protested the project, citing concerns with what they believed was mudand clay-like substrate being used in the river. The Dorchester County Council also got involved in the 2014 protest, citing concerns that the substrate is interfering with crabbers’ trot lines.
In the Tred Avon River, the DNR asked the Army Corps to delay the construction of the remaining 8 acres of planned oyster reefs, which was slated to start in the beginning of 2016, until a study on the Harris Creek oyster sanctuary that’s due in July is released.
Watermen’s concerns with the Tred Avon project lie in historical numbers they say they pulled from the DNR’s website on oyster recruitment in Harris Creek and its neighbor, Broad Creek, which is open to oyster harvest.
Watermen claimed in December that Broad Creek’s oyster population recruitment is better than that in Harris Creek, despite the multimillion-dollar effort to restore populations in Harris Creek.
However, the numbers watermen have used have been disputed by some scientists associated with oyster restoration.
Westby said that, due to the calls for delays in the Little Choptank and Tred Avon rivers, reef construction in those rivers will not happen at the pace that was originally set, and there might need to be some modification to the plans. But, seed plantings on the already constructed reefs, and some bottom that doesn’t need a constructed reef, will happen on pace, she said.
Throughout the interagency workgroup’s report, it notes that disease is a factor that may influence the success of the Choptank River complex oyster sanctuary projects, which is the largest effort of its kind in the world. One reason scientists say the Chesapeake Bay’s oyster population has been depleted to such low levels is the disease that has plagued the population.
Westby said weather conditions in recent years have been ideal to stave off disease, but should there be a hot, dry summer, there could be a disease outbreak, which might result in some mortality.
To view the full Oyster Restoration Interagency Workgroup report, visit www.chesapeakebay.noaa. gov.
Follow me on Twitter @ jboll_stardem.
In this July 2014 file photo, 15 tons of shells with oyster spat set on them are piled on board Patricia Campbell, the boat the Chesapeake Bay Foundation uses for restoration work and spat plantings.