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Impacts from Hurricane Florence to North Carolina wild oysters have been observed nearly coast wide. The North Carolina Division of Marine Fisheries (NCDMF) oyster management dredge sampling outside of the bays in Pamlico Sound revealed large areas of completely dead or areas of low density and primarily under legal size (less than 3-inch shell length) living oysters. Mechanical harvest for the 2018 – 2019 oyster season in Pamlico Sound was closed on Dec. 13 due to all four management areas within the sound having tripped the less than 26 percent legal size management trigger on at least two consecutive sampling events. This was the earliest closure to the mechanical harvest fishery since the implementation of this management tool.
During October, dive surveys on Middle Grounds in Pamlico Sound, North Carolina State University (NCSU) researchers found only four live oysters out of approximately 20 quadrat samples excavated. They reported hypoxic and anoxic dissolved oxygen conditions and encountered numerous recently dead individuals, mostly new recruits. Additional observations by the NCSU team found that oyster reefs in the shallow bays were not as severely impacted as deep-water reefs with most locations exhibiting relatively low recent mortality.
NCDMF cultch site selection work in October revealed limited evidence of recent mortality at shallow subtidal reef sites examined in Pamlico Sound and its tributaries and greater evidence of mortality was observed in Newport River.
NCDMF collected samples both before and after Hurricane Florence from the Swan Island Oyster Sanctuary. A reduction in sublegal oysters, suggesting a mortality event, was observed post hurricane. However, there was also evidence of a strong recent spat recruitment to the site.
In the southern region of the state, significant oyster mortality associated with Hurricane Florence has been recorded and reported from areas including Stump Sound and the Cape Fear River. NCDMF sampling was conducted post-hurricane at a recently deployed artificial reef located in Carolina Beach State Park to assess oyster utilization. The material was consistently covered in spat that had grown to approximately .75 inches in length before all dying. The spat mortality is expected to have resulted from hurricane related water quality effects. The entirety of the Carolina Beach State Park Marina stretching to the Snow’s Cut Boat Ramp across from the Carolina Beach Inlet was observed to have 100 percent oyster mortality. This includes all oysters on marsh edges, bags and rock walls. This mortality event in the Cape Fear River is reported to extend down the entire estuary to the river mouth. Upcoming annual NCDMF spat sampling efforts will also reveal any impacts to cultch planting sites across the state.
For more information, contact Joe Facendola with NCDMF at Joe.Facendola@ncdenr.gov.
NCSU oyster dredge sampling in Pamlico Sound after Hurricane Florence.
Dead oysters collected during NCSU dredge sampling in Pamlico Sound after Hurricane Florence.
Evidence of recent mortality in oysters sampled from Pamlico Sound by NCSU after Hurricane Florence.
The North Carolina Department of Marine Fisheries (NCDMF) monitored the newly created Swan Island Oyster Sanctuary in August 2018, as part of their annual monitoring effort, and again in November after Hurricane Florence. Monitoring results show that overall the number of oysters in the sanctuary increased after the storm. A bump in oyster spat was seen after Florence and accounts for the majority of the overall oyster population increase at this site during this timeframe. The NCDMF attributes this increase in spat to seasonal oyster spawning that occurs when the water temperature decreases. The observed decrease in sub-legal oysters is possibly due to a combination of cohort promotion and some mortality effect on this size class. The count decrease could also be a function of sample variability. The site will continue to be monitored in years to come.
Note: Spat are oysters less than 25 mm in size, sub-legal oysters are 25-75 mm in size and legal oysters are greater than 75 mm.
A multi-stakeholder group worked together to create a shellfish mariculture plan for North Carolina in order to grow the industry in a sustainable way. Shellfish mariculture is the cultivation of oysters, clams, mussels and other bivalves in contained areas in estuarine waters. Because most bivalves are filter feeders, mariculture helps improve water quality. North Carolina has great potential to lead the way in oyster mariculture because of its clean water and the dedicated scientists, fishermen, and policymakers who support the development of this industry.
In 2017, the North Carolina General Assembly passed Section 13.13 of Session Law 2017-57, directing the North Carolina Policy Collaboratory at UNC-Chapel Hill to use a stakeholder process to prepare a Shellfish Mariculture Plan for the state by December 2018. To fulfill this mandate, the Collaboratory is partnering with the University of North Carolina – Institute of Marine Sciences and other relevant stakeholders. The partnership is utilized the expertise of the North Carolina Coastal Federation’s long-established and effective oyster stakeholder group that helped prepare the 2015 Oyster Restoration and Protection Plan for North Carolina. A subset of this group focused on developing the Shellfish Mariculture Plan. Development of this plan was a key step in implementing the mariculture goal of the Oyster Restoration and Protection Plan for North Carolina that includes seven major goals related to oyster restoration and mariculture.
By law, the Shellfish Mariculture Plan includes an evaluation of best practices in other states and nations, analysis of siting strategies for shellfish mariculture operations and recommendations for improvements to legal protections for mariculture operations, cultch planting and strategies for control of shellfish pests. The Collaboratory, in consultation with various stakeholders, also developed conceptual plans and recommendations to promote the state’s shellfish harvesting heritage, including the creation of a North Carolina Oyster Trail and a state Oyster Festival.
Despite a trending decline in oyster populations over the last 200 years in North Carolina, the remaining reefs continue to support a multimillion-dollar commercial fishery ($4,045,444 ex-vessel value in 2016), as well as valuable recreational fisheries. However, the wild stock remains unassessed as there is insufficient data to conduct a traditional stock assessment in North Carolina, limiting the North Carolina Division of Marine Fisheries’ (DMF) ability to estimate population size and rate of removal.
While considerable effort has gone into aquaculture advances and habitat rehabilitation, less funding has focused on fishery-independent data collection to better manage the wild population of oysters. In fact, a traditional stock assessment has never been completed in the history of the fishery in North Carolina. With this need in mind, a new project is taking a different approach with a clear goal of designing a statistically robust, cost-effective fishery-independent population survey methodology for subtidal and intertidal oysters in North Carolina. North Carolina State University and the Nature Conservancy are working with DMF, North Carolina local oystermen and regional university colleagues to develop this sampling methodology and pilot it in a 20-acre natural reef in the Middle Ground region of Pamlico Sound. With this new sample design, it is hoped that the data gaps currently surrounding the fishery can be filled, which will allow for the future development of a stock assessment. In addition to this pilot study, commercial oystermen will also assist in investigating and quantifying oyster bycatch mortality, another important data gap in fisheries management. Finally, this project will help to map and illustrate the rate of change in the intertidal oyster population south of the Back Sound in North Carolina.
Once completed, the project will recommend fisheries-independent sampling procedures that will support a fisheries-independent sampling program for the wild oyster population in North Carolina by DMF, as well as quantify bycatch injury and mortality of oysters from dredging gear that is important to capture when estimating total mortality rates of oysters. A noteworthy component to this project is the involvement of fishermen in the fisheries sampling design and process. The hope is that moving forward, this survey will instill confidence in fishermen with the robustness of the new sampling and the survey will be responsive enough to allow for a more thorough and time-sensitive assessment of the resource. At the end of the day, we all share a similar goal, a thriving and sustainable fishery.
Contact Dan Bowling for more information on future stock assessment projects.
North Carolina to launch state Shellfish Initiative at public event on Aug. 2
MOREHEAD CITY — North Carolina will officially join a national effort that demonstrates the social, economic and environmental importance of shellfish at a public event at the North Carolina State University Center for Marine Sciences and Technology (CMAST) on Aug. 2 from 10 a.m. until noon.
Michael Regan, secretary of the North Carolina Department of Environmental Quality (NCDEQ), will announce Governor Cooper’s support for the North Carolina Shellfish Initiative. The statewide initiative is modeled after the National Shellfish Initiative — the National Oceanic and Atmospheric Administration’s (NOAA) program to increase the population of shellfish in the nation’s coastal waters. The North Carolina Shellfish Initiative will advance the State’s work to strengthen the coastal economy, create jobs and promote sustainable seafood and shellfish restoration.
The new state initiative prioritizes four goals: job creation, protection of water quality, protection of shellfish health and sustainable management.
The North Carolina Shellfish Initiative reflects the growing importance of shellfish conservation and the industry’s benefits to the coastal economy. North Carolina is the sixth state in the country and the first in the southeast to follow the federal model and establish an initiative to increase shellfish.
State shellfish initiatives provide a vehicle to leverage existing partnerships, grant programs and regulatory authorities to maximize the benefits of shellfish. Establishing innovative partnerships among state agencies, local governments, the federal government, the shellfish industry and nonprofit organizations is an effective and efficient way to maintain both vibrant coastal communities and healthy coastal ecosystems.
“North Carolina has a history of collaboration among public, private and academic sectors to transform ideas into actions that advance shellfish restoration and mariculture,” said Dr. Ken Riley, a marine ecologist with NOAA’s National Centers for Coastal Ocean Science. “Over the last 15 years, the state has garnered public attention with significant investment in shellfish restoration and the growth of the shellfish farms. NOAA is pleased to partner with the State contributing tools and expertise for siting shellfish farms and oyster restoration projects, which increase opportunities to sustainably harvest shellfish.”
The Aug. 2 announcement is open to the public and will begin with brief remarks from Sec. Regan as well as representatives from other federal, state and private stakeholders involved in shellfish restoration, production and research and development.
Following these remarks, reporters and the public are invited to participate in a short walking tour around CMAST’s campus to learn more about North Carolina shellfish activities and programs from industry, agency, university, and nonprofit partners. The tour will include a visit to the North Carolina Sea Grant Shellfish Farming Demonstration Center, a regional technology center and proving ground for training prospective growers such as commercial fishermen wishing to enter the mariculture industry.
By leveraging partnerships and sharing knowledge and resources through the North Carolina Shellfish Initiative, partners will be able to preserve the state’s rich shellfish history while also fostering a sustainable future.
For more information, contact Erin Fleckenstein with the North Carolina Coastal Federation at firstname.lastname@example.org.