Rodriguez Lab

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.

[vimeo]http://vimeo.com/72269708[/vimeo]

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.

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.

This week we were collecting transects of cores across Onslow Beach, NC to measure the thickness and carbon content of peat and organic-rich sediment preserved below the island and accreting in the backbarrier.  Taylor Bennett, an undergraduate student from Mount Holyoke College, is working with some of these data for her Research Experiences for Undergraduates project.  She will be at IMS for a couple of months.  Below is a video of the transect of cores she is working with.  We collected those data on Monday and had to bushwack our way through that thick Phragmites grass.  It was Taylor’s favorite field excursion so far.

[vimeo]http://vimeo.com/67839220[/vimeo]

Ethan is exploring new ways of estimating carbon budgets for saltmarshes as part of our paper-writing working group (with the Fodrie Lab) that meets every Monday afternoon (and for his dissertation).  We needed some help measuring rates of marsh accretion at Carrot Island, NC and convinced  John Gunnell and Brent McKee to team up with us.  On Monday May 20th we collected four cores of the saltmarsh that John will develop Pb-210 profiles from.  Hope the wild horses didn’t disturb the area too much.

Erosional scarp at Carrot Island, NC

Taking gear off of the boat at the end of the trip. 

On Tuesday May 14 we visited the Roanoke River to collect some data with Anna for her dissertation.  Anna is interested in better understanding the connectivity between the river channel and floodplain in terms of exchanging particles.  We have three monitoring stations set up along the floodplain with water-level loggers and marker beds.  We were only on the water for about 3 hours collecting cores through the marker beds and reading out the sensors.  On the way home we purchased 24 30-foot aluminum tubes for vibracoring later in the summer (maybe on Monday if the weather holds) so stay tuned.

Anna taking a core and examining how much sediment is above the feldspar layer.

The water level logger deployed on the floodplain.