Back in July we spent the day with David Huppert, who was producing a video story on oyster-reef restoration for the PBS show Quest. He tagged along with us while we collected some laser-scanning data from a natural reef near Shackleford Banks, NC. Click on the image below to view the video. Thanks for including our work in your story, Dave.
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Tagged ocean, outer banks, oysters, pbs, public media, QUEST, reef, restoration, Science, timelapse, unc-tv, UNCTV, water
Island overwash forms new intertidal substrate (washover fans) for saltmarsh colonization. As a barrier island moves landward in response to sea-level rise, that marsh sediment will eventually be eroded on the shoreface. To develop coastal carbon budgets, it is important to measure rates of marsh accretion and landward movement of the island. We are collaborating with Brent McKee and Carolyn Currin to obtain those data.
Taking a 1-m long core near one of Carolyn Currin’s SETs
Ground surface after core extraction.
After the core is collected, we slice it up in 1 cm bins back at the lab. It is difficult cutting through marsh grass so Ethan brought in an electric meat carver, which worked great. Check out the movie of Dr. McKee using the meat carver (below). $29.99 at Walmart or if you need to purchase it using a grant, UNC negotiated a special price of $200.00 with a government-approved vendor. Watch the video below (or click here if it is not being displayed) of the core being sectioned and notice the variations in biomass down core. Each frame is 1 cm down core starting at the ground surface. The last few frames are below the marsh.
The Institute for the Environment (IE) class is learning about coastal geology this week by experiencing it first hand. Walther’s Law tells us that the vertical succession of facies reflects lateral changes in environment. That concept is an important part of the coastal geology foundation and we learned how to apply it by collecting a vibracore from an old flood-tidal delta deposit that was active 1800 AD. The old flood-tidal delta is part of Bogue Banks, NC and is located just across the sound from IMS. The IE class brilliantly identified sediments deposited in the salt marsh, flood-tidal delta, and Bogue Sound environments, all stacked on top of each other and sampled in our core.
We collected 8 cores from the New River Estuary to help our colleagues at VIMS and UCONN derive a carbon budget for the estuary. Cores were collected using the R/V Jenny and transported to IMS for subsampling. Brent McKee will be measuring sedimentation rates from the cores in his lab at Chapel Hill. Others will be looking at the amount and type of carbon preserved in the estuary through time.
Cores ready for transport to the lab.
Brent McKee commenting on the productive day we had.
Understanding how oyster reefs grow is important for restoration and predicting oyster-reef response to accelerated sea-level rise, degrading water quality, and harvesting. In an attempt to map small-scale changes in oyster-reef morphology we are experimenting with terrestrial LIDAR. Click on the link below to see a visualization of the reef (courtesy of Justin Ridge). In two years we will revisit the reef and hopefully be able to resolve morphologic change.
Justin at the ship’s helm.
We know there is a buried oyster reef below the bay floor because we sampled it in a core, but how large is the reef and how rapidly did it grow? To help answer that question, Justin and I embarked on day-long adventure collecting CHIRP data in a grid pattern around where we sampled the reef. I’ve imaged oyster reefs very clearly in other places, but watching these data scroll across the computer screen in the field was a bit disappointing because the reef was not always easy to identify. The North River Estuary is very shallow, about 1 m deep at high tide, which explains our choice of research vessel. One thing I did learn is that Justin is an amazing boat driver at 2.5 knots. The spacing between our lines was only 100 m.
The North River Estuary and the grid of data we collected. Look at that fish in the water.
Photo taken by Pete Bell. Follow him on instagram: chickenstagrams
QUEST joined us in Back Sound, a shallow body of water behind Shackleford Banks, North Carolina, to learn about our work with oyster reefs. We were laser scanning a natural reef that formed on a sandflat in an area that is thought to be an old flood-tidal delta. We anticipate that the part of the reef that is growing vertically most rapidly is exposed to air 40% of the time and exists in a ring around the center of the reef. The full moon and southwest wind made for an extreme low tide and most of the area was exposed. Two years from now we will scan the reef again to see if our hypothesis was supported.
Group photo. Humid day. Check out the horses in the background.
Last week Ethan, Justin, and Taylor visited that washover fan on Onslow Beach that formed during Hurricane Irene to measure aeolian transport during a wind event. They noticed that backbarrier marsh and oyster reefs were being buried by wind-blown sand. Previously, we documented that wind-blown sand contributes to backbarrier marsh accretion (see our list of publications), but burial of an oyster reef by wind-blown sand is not a common occurrence. They did a great job documenting the burial event with video and photos. Every time we visit Onslow Beach there is something new to see and learn.
This is what the beach at Pine Knoll Shores (Bogue Banks, NC) looked like around 6 pm on June 7 as the storm passed by.