Efforts On to Rebuild NC’s Oyster Population

North Carolina’s estuaries were teeming with oysters 150 years ago. In the time since, a combination of factors has caused oyster populations to decline.

Development, urbanization, point and nonpoint source pollution, intensive farming, harvest pressure, and increases in the frequency and intensity of extreme weather events such as freezing temperatures, hurricanes, heavy rains and prolonged winds have all contributed to the loss, said state marine ecologist Jason Peters.

As supervisor of North Carolina’s cultch planting program, Peters has been heading up an effort by the Department of Environmental Quality’s Division of Marine Fisheries to rebuild the oyster population.

“Cultch planting is an oyster restoration technique employed by many states along the East and Gulf coasts to return hard bottom habitat to our estuaries. This hard-bottom habitat, usually in the form of oyster shell of fossilized limestone marl, is placed in areas with suitable conditions for recruitment, growth and survival of oysters,” said Peters, who also supervises the state’s artificial reefs and oyster sanctuaries program. “The objective of this program is to mitigate habitat loss from harvest or natural events by establishing new, successful oyster reefs.”

Erin Fleckenstein is coastal scientist with the Wanchese office of the North Carolina Coastal Federation, which publishes Coastal Review. She explained that cultch planting activities are part of a comprehensive strategy to build back oyster resources and support a wild harvest fishery in the state.

Fleckenstein heads up the statewide Oyster Restoration and Protection Plan for North Carolina: A Blueprint for Action. The federation was set to announce Tuesday the fourth edition of the blueprint, which provides direction and guidance for restoration, management and economic development strategies to benefit to the environment and economy for the next five years.

“Areas planted with cultch material provide a foundation for new oyster growth. As the oyster reefs grow, they provide homes for other fish, help to filter the water in the sound and as they are harvested, they support our local economy and culture — food, filter, fish as we like to refer to it,” she said.

Since 2008, on average, the Division of Marine Fisheries has gradually increased annual deployment volumes of cultch with some fluctuations. In 2020, the division planted an unofficial total of 323,589 bushels, about 20% greater than the 10-year rolling average, Peters said.

Cultch reefs, as with all oyster reefs, benefit habitat and estuaries by providing a suite of ecosystem services such as water filtration, refuge for fish, crabs and other invertebrates, foraging grounds for predator species, sediment stabilization, and wave attenuation, Peters said. “To some degree, these artificially developed oyster reefs may also help alleviate harvest pressure on more fragile natural reefs nearby.”

Cultch planting in North Carolina has been taking place since 1915, more than 100 years, in some form or fashion, he continued. Since then, more than 22 million bushels of cultch has been planted to develop thousands of sites and likely tens of thousands of acres of habitat.

“I should note though, that cultch habitat is not necessarily long-lived – about five years or so — so much of that acreage has come and gone,” he said. Now, the effort is a bit more organized and receives broad support from the public to the General Assembly, which provides 100% of the funding for cultch planting.

“General Assembly funding helps place North Carolina as a national leader in oyster restoration. Without this support, large-scale cultch planting and oyster restoration would not be possible,” he said.

He noted than in 2018, the state became one of nine to join the National Oceanic and Atmospheric Administration’s National Shellfish Initiative, “galvanizing support of local, state, and federal leadership to promote sustainable seafood, shellfish restoration, and clean water.”

The cultch planting program constructs expansive reef sites open for commercial or recreational harvest.

“Many commercial harvesters request the locations of cultch planting sites and others report successful harvests. For recreational anglers, these areas serve as excellent fishing grounds for popular sport fish such as trout, flounder and red drum,” Peters said.

Chris Cuthrell, an oysterman and crabber in the state’s northeast region, said cultch planting is a big help to the industry.

“The cultch planting helps give the spats somewhere to attach to help them start growing. When the shells on the bottom get covered in slime or any other growth that prohibits the oyster larvae from attaching to the shells then there is no new growth for the future,” he explained.

“The cultch program assures that there is a clean surface for it to attach to. This winter most of the boats in our area worked on places that started out as clutch planting areas. This is a big help to our industry because a lot of the natural beds have been spread out and the shells have sunk in the mud or become an unsuitable place for the spats to attach to. In my opinion the cultch planting program is vital to sustain the wild oyster stock.”

Peters explained that the division’s mission is to manage fisheries resources for sustainable use, which steers how cultch planting plans are developed. As part of that, the division reaches out annually to the public for suggestions on locations for oyster cultch planting.

“Each year, division staff evaluate decades of cultch planting data and utilize university research and mapping tools to select suitable sites for cultch planting within federally authorized areas. Before finalizing our proposed locations, we hold a series of public meetings to gather local knowledge from harvesters and other stakeholders to tweak our plans,” he said. These meetings are typically held later in the year.

Ted Wilgis, senior coastal specialist at the federation’s southeast office in Wrightsville Beach, reiterated that it’s important to have the public share their experiences and expertise with division staff to help guide cultch locations.

There’s a lot of people who hold shellfish licenses in the southern area of the state, and it’s important for these harvesters to give locations of where the oysters are being taken, Wilgis said.

“DMF knows what waterbody the shells are mostly coming from, but they don’t know all the spots,” he said. If shellfish lease holders shared the areas they harvest, the division can keep an eye on the population as well as show the General Assembly continued public interest in the project.

Wilgis added that when the division asks for comment, it’s an opportunity to voice conflict with an area or request a location. If people have any issues with potential locations because it’s their favorite kayaking or paddleboarding spot or if a fishing guide has noticed a spot is being depleted that was once plentiful, this is the time to speak up.

Wilgis said that the federation partners with the division in the sense that they’re trying to support the program by providing resources, helping work with legislators to support funding for the program, demonstrate its need, and look for ways to bring more resources and stakeholders to the process.

“We definitely do everything we can to support the program and look for ways that make it even more effective,” Wilgis said.

Cultch planting is important in state waters, especially in the southern and central regions, Wilgis said. “We’re what’s called ‘substrate limited,’ meaning with oysters, we have a fair amount of larvae in the water, which is good, but they need a place to land.”

The southeast and central areas have only about 6% of the shellfishing waters in the state but produce about 40 to 50% of the wild harvest annually, Wilgis said. Because of such a small area producing so many of oysters, the pressure is hard on the reefs, which is why enough material needs to be put back in the water to balance what is being taken out for harvest.

And, he added, “oyster reefs are great places to fish and so it also supports recreational and other commercial fisheries.”

He said that without the material being replaced, it becomes harder and harder to harvest oysters. They’re starting to see a greater decline in landings and in the population.

Wilgis said the federation is also supporting the program through shell recycling and bringing more attention to the North Carolina Oyster Trail, which provides tourism experiences focused on oysters.

Peters recognized the work that goes into this program and saluted “the talented and hardworking staff who perform this work every year. The planning, development, and implementation of cultch planting requires expertise from trained scientists to heavy equipment operators and master captains. The division gathers this expertise from a surprisingly small staff, who literally and figuratively move mountains to make cultch planting a success. Those folks are the unsung heroes of this great effort.”