Oyster Reefs

 

Oyster reefs are the only natural hard structure in many coastal estuaries. As sea-levels rise and storm impacts worsen, these reefs can provide protection for easily-eroded marshes. Research is needed to optimize reef growth for living shorelines applications and understand what drives reef survival and morphology. 


This ongoing research is funded by the USCRP 

Centuries of Reef History

Vibracores through living oyster reefs allow us to measure the age of the reef and examine the environmental history of it's growth. Once opened, the core can be sampled for shell content, grainsize, organic content, and material for radiocarbon dating.  Many reefs in NC estuaries have existed in the same location for hundreds of years, building vertically upon old shell to keep up with sea-level rise and prevent sediment burial. 

three people stand on a oyster reef surrounded by water and marsh. They hold up a long aluminum core tube vertically with the base resting on the oyster reef.

Researchers prepare to sink a core tube into a natural oyster reef located in Ward Creek, NC. 

A sediment core tube opened and laying on a lab bench. The core has been sliced lengthwise (hotdog style) to expose the sediment captured in the tube.

A core tube opened to expose the shell and sediment for sampling and radiocarbon dating. 

Living Oysters

Measuring elevations and sampling living oysters around a reef in the Rachel Carson Preserve, NC. Living oyster density and growth are not constant across the reef, resulting in differing rates of  accretion over the area of the reef, and possibly leading to the elongated shapes these reefs often take. 

Two researchers wade in shallow water near an oyster reef extending out from a marshy area. One researcher rinses a screen in the water used to collect and count living oysters.

Researchers collect representative samples of living oysters from different locations around an elongated reef. 

Presentations

Eisemann, E.R., Rodriguez, A.B. (December 2023) Natural intertidal oyster reef loss due to marsh encroachment. Oral presentation at the 2023 AGU Annual Meeting. San Francisco, CA.  https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1302664