{"id":40955,"date":"2024-03-07T08:21:01","date_gmt":"2024-03-07T13:21:01","guid":{"rendered":"https:\/\/news.maryland.gov\/dnr\/?p=40955"},"modified":"2024-03-12T16:10:50","modified_gmt":"2024-03-12T20:10:50","slug":"marylands-oyster-restoration-sanctuaries-show-promising-signs-for-shellfish-recovery","status":"publish","type":"post","link":"https:\/\/news.maryland.gov\/dnr\/2024\/03\/07\/marylands-oyster-restoration-sanctuaries-show-promising-signs-for-shellfish-recovery\/","title":{"rendered":"Maryland\u2019s Oyster Restoration Sanctuaries Show Promising Signs for Shellfish Recovery"},"content":{"rendered":"

At restoration sites, oysters are establishing dense, productive reefs<\/span><\/i><\/p>\n

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A restored oyster reef in the Harris Creek sanctuary in 2021. In a thriving oyster reef, oyster shells accumulate into three-dimensional structures where crabs scuttle, sea squirts dangle and fish dart through clearings. Like coral reefs, oyster reefs support an ecosystem that flourishes around them. Photo by the Smithsonian Environmental Research Center.<\/p><\/div>\n

At first, oyster biologists were concerned. Monitoring efforts at some restoration sanctuary reefs in 2022 weren\u2019t pulling up many oysters, even though the sites had previously been performing well.<\/span><\/p>\n

So divers with the Oyster Recovery Partnership went into the water to investigate. What they found there wasn\u2019t a shortage of oysters, but such a dense and mature population that the shellfish had cemented into three-dimensional reefs, thick enough that the team\u2019s patent tongs sampling gear weren\u2019t able to get them out of the water.<\/span><\/p>\n

\u201cWe\u2019re excited because we feel like we\u2019re starting to reach our goal of self-sustaining reefs,\u201d said Olivia Caretti, the partnership’s coastal restoration program manager. \u201cIn another sense, it becomes a question of how we adjust our sampling plan. It\u2019s a good problem to have.\u201d<\/span><\/p>\n

These sites in the Tred Avon River are a part of an ongoing and long-term experiment in oyster recovery. In an effort to shore up declining numbers of the bivalve, Maryland dramatically expanded oyster sanctuaries in 2010 to cover 24% of historic oyster habitat in the Bay, a span of about 9,000 acres spread over a wide geographical area.<\/span><\/p>\n

Then, in June 2014, Maryland and other regional governments signed onto the Chesapeake Bay Program\u2019s Chesapeake Bay Watershed Agreement that outlined a goal to \u201crestore habitat and populations in 10 tributaries by 2025 and ensure their protection.\u201d<\/span><\/p>\n

Maryland and Virginia split these 10 tributaries, and both states embarked on five large-scale restoration projects. In Maryland, these are known as the \u201cBig Five\u201d sanctuaries in Harris Creek and the Little Choptank, Tred Avon, St. Marys, and Manokin rivers.<\/span><\/p>\n

Now, nearing 10 years after the agreement, Maryland\u2019s restoration sanctuaries are on track to be completed in time to meet next year\u2019s goal. Across these restoration sanctuaries, scientists are finding impressive signs of recovery, with considerable reproduction and the establishment of dense, vertical oyster reef structure.<\/span><\/p>\n

\u201cThe success of these restoration sanctuaries is a testament to years of dedicated work,\u201d said Maryland Department of Natural Resources Secretary Josh Kurtz. \u201cDNR and our partners are taking oyster restoration seriously, and it\u2019s great to see our efforts result in these productive, living reefs.\u201d<\/span><\/p>\n

The restoration work is carried out by the Chesapeake Bay Program\u2019s Maryland Oyster Restoration Interagency Workgroup, a partnership between the National Oceanic and Atmospheric Administration, the U.S. Army Corps of Engineers Baltimore District, the Oyster Recovery Partnership and the Maryland DNR.<\/span><\/p>\n

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Shell drops from a boat into the Choptank River for a 2016 planting. DNR photo by Mitch Cannon<\/p><\/div>\n

Of Maryland\u2019s Big Five restoration sanctuaries, initial restoration is complete at four, and Harris Creek is considered fully restored. In 2022, Harris Creek had an average density of 462 oysters, including spat and small oysters, per square meter.\u00a0<\/span><\/p>\n

At the fifth large-scale restoration sanctuary, Manokin River, initial restoration work began in 2021 and DNR estimates it will continue until 2025.<\/span><\/p>\n

Evaluating the Oyster Restoration Sanctuaries<\/b><\/p>\n

The restoration sites are exceeding success metrics established by the Maryland Oyster Restoration Interagency Workgroup. The workgroup\u2019s\u00a0 <\/span>2021 Oyster Monitoring Report<\/span><\/a> on these large-scale restoration sites showed that 100% of 3-year-old and 6-year-old reefs that year met the minimum success criteria for oyster density\u201315 oysters per square meter over 30% of the reef area. More than 90% of the reefs had more than 50 oysters per square meter in the same area.<\/span><\/p>\n

The 2022 and 2023 reports are scheduled to be released this spring, but DNR scientists think it\u2019s likely that the trends already seen will continue.<\/span><\/p>\n

\u201cThe five large scale sanctuaries have significant populations of oysters, given the massive plantings and the occurrence of natural spatset,\u201d DNR Shellfish Division Director Christopher Judy said. \u201cThe next monitoring report will likely show a continuation of past results.\u201d<\/span><\/p>\n

DNR\u2019s own<\/span> oyster monitoring<\/span><\/a> across the Bay has found that restored sanctuaries are high in oyster density, reproduction, and cultch (the shell or substrate necessary for juvenile oysters to grow on) as well as low in mortality.\u00a0<\/span><\/p>\n

From<\/span> 2012 to 2022, DNR spent $49 million to restore oysters in the five large-scale sanctuaries. By the end of 2022, partners had planted 5.93 billion juvenile oysters and created 894 acres of oyster reefs at the Big Five sanctuaries, according to the working group\u2019s <\/span>2022 Chesapeake Bay Oyster Restoration Update<\/span><\/a>. Previously, these sites had only 42 acres of existing reefs that met the restoration metrics, which did not require initial restoration.<\/span><\/p>\n

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A DNR staff biologist assesses oyster shells for spat, or juvenile oysters, as part of the 2015 fall oyster survey. DNR photo by Joe Evans<\/p><\/div>\n

The Need for Oyster Restoration<\/b><\/p>\n

Scientists and environmental advocates say this considerable undertaking was necessary to begin to address the need for oyster recovery.<\/span><\/p>\n

Once far more abundant in the Bay, eastern oysters plummeted to a fraction of their early-1800s population due to historic overharvesting, disease-related mortality, habitat degradation, and reduced water quality.\u00a0<\/span><\/p>\n

The bivalve is a keystone species, a critical part of the ecosystem of the Bay, as well as an economic driver for the region, making restoration a priority. Oysters also serve as natural filters in waterways. Scientists estimate that adult oysters <\/span>can filter more than 10 gallons per day<\/span><\/a> in the Chesapeake Bay.<\/span><\/p>\n

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