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ENC Regional News
Thu April 26, 2012
New Oyster Restoration Project
New Bern, NC – A public meeting was held Tuesday in Morehead City concerning a planned oyster restoration project at the mouth of the Neuse River. Over the past 16 years The Division of Marine Fisheries restoration team has constructed ten oyster sanctuaries along the Carolina coast to combat the decline of marine life and habitats. There is one established sanctuary in the Neuse River, the others are in the Pamlico sound, including West Bluff Bay, Gibbs Shoal, Ocracoke, and another further north in the Croatan Sound. Biologist and project coordinator of the oyster restoration team, Pelee Holmlund, says they've had success with existing sanctuaries.
"and on an annual basis we go out and quantify the oysters on the sanctuaries. We count and measure how many oysters there are and how big they are, and for instance in the Neuse river oyster sanctuary which is in close vicinity to this new project we have higher recruitment and mortality, and as of now we have a conservative estimate of about fifteen million oysters in that sanctuary."
Tuesday's meeting outlined the viability of a new proposal and a new experiment to compare the quality of different materials as housing for the oyster habitat.
Oyster reefs are a foundation of marine eco systems. The Sanctuaries are different from other projects in that they create a nature preserve, one that gives over 300 species of fish an ecosystem, and in the end help commercial fisherman in areas extending far outside the sanctuary.
"all the structures that we plant inside these sanctuaries are protected and their protected in regards to the use of bottom disturbing gear, and so there won't be any commercial fishing with trawls or dredges in this area, and that will maintain the reefs."
Pelle says recreational fishing will be allowed on the sanctuary, as it does not harm the aquatic floor.
The Neuse River location they've chosen provides the means for mature oysters to develop a reef and spread a brood stock to naturally established habitat's in the area.
Little Creek Oyster Sanctuary is at a depth of 19 to 22 feet, the deepest oyster sanctuary site yet. The site is located in Carteret County approximately 10 miles east of Oriental and 1.8 miles northwest of Little Creek in the lower Neuse River. It's a sixteen-acre proposal, sanctuary sites generally range from five to thirty acres. Even though the larger goal of the project is upwards to 500 acres of oyster reef habitat on the Pamlico Sound, and 100 in the Neuse, Pelle says there's evidence that the smaller reefs tend to do better.
"instead of having one large one well have several points where the oysters can spawn and in that way they will cover a larger are with their larvae dispersal."
Together with the idea for smaller, more dispersed reef settlements, the team has found evidence that using concrete materials will provide more efficient means of building oyster reefs and reduce the construction footprint. Pelle says Little Creek is the first site they will use for the material experiment.
"In addition to limestone riff raff we will deploy various concrete structures, such as reinforced concrete pipe, concrete blocks, and also artificial reef structures such as ultra balls and Florida reefs, and the idea with that is to try and found out which of these artificial reefs can produce most oysters per meters square, and also which reef product provides the most surface area for settling surface larvae."
Each mound supports up to 500,000 oysters. Limestone riff raff are blocks they've used in the past from mines in New Bern, but the concrete has proven advantages that outweigh the use of limestone. The concrete pipe is recycled from concrete plants, cinder blocks are being tested, and structures called Florida reefs and ultra balls. The Florida reefs resemble houses. The largest area will be covered with ultra balls which look like termite mounds. The other common feature of the structures is their hollowness; it provides a larger surface area. They also reduce the effects the mounds have on the main feature of these oyster sanctuary sites, the soft bottom floors.
The soft bottom of the Carolina Coast is characterized by its mud and its tendency to erode quite easily. The soft mud environment is further marked by its lack of vegetation, and therefore lack of living marine life. Pelle says they look for these soft bottoms, but they have to find special ground that's supported oyster growth in the past.
"there's allot of different types of soft bottom sediment. What we're looking for particularly for these sites is a bottom that is firm enough to hold structures on top of it so that they won't sink in, but it can't be firm enough to hold sand, like in a beach environment because that's a sign there's likelihood that the material you placed in the substrate will get sanded in."
As proven by the dredging and trawling, If the reef get sanded in, then the whole reef is threatened by suffocation.
Our Neuse River and the Pamlico Sound are estuaries, areas partially surrounded by land that connect two bodies of water. Artificial reef coordinator at the Division of Marine Fisheries, Jim Francesconi, stresses the importance of estuaries as monumental proponents for marine diversity.
"it is well documented that anytime you have adjacent habitats your population numbers and diversity is highest and I put allot of emphasis on the diversity too and then you have so many more species that are just requiring this type of environment, and of course that's where people live, and we also look at the estuary for so many facets of our life."
He also says that the connection between these two very distinct bodies of water accommodates some types of fish in their most crucial stage of development.
"the opportunity to have an oyster rich environment or a marsh environment as nursery areas. The thing is we're talking into the hundreds of commercially and recreationally important finfish species that require the nursery areas in North Carolina for the most critical stage in their life history being juvenile. You know the eggs might be spawned and fertilized but the larvae will come in from the ocean into the estuarine environment and the first five to eight months of their life are so wholly estuarine dependent that without this estuary we would just absolutely not have these species."
According to Pelee over the last century we've lost 90 percent of our oyster reefs due to trawling, dredging, human development, and disease. As a result oyster mortality rates run out of proportion to oyster growth. Humans are now stepping in to restore what was a natural ecosystem. Oyster reef degradation was already in full swing by 1910, in 1880 companies from Boston moved to the coastal Carolinas and opened Canaries, and with it overfishing, and dredging.
The division of Marine Fisheries applied for the Little Creek grant last year, in August they received approval for it, a total of 950000 dollars, now they are waiting on the state administration level for the Army Corp of Engineers in Wilmington to pass the funds to them. They want to begin construction at Little Creek in spring of 2013, and estimate it will be complete in about eight weeks. Barges are loaded with the concrete, ride out to the sub tidal zones, and dump it. Another grant, that's been approved, will establish a sanctuary in Manteo, another outside of Cedar Island, and one on the Cape Fear River.