Sapelo Island - DD

Learning the Living Shoreline Monitoring Protocol

 By David DeSalvo

(Photos courtesy of Betsy Kane, CCGA) 

On October 28th, 2011 our conservation class went to Sapelo Island to learn the protocol for monitoring a restored Living Shoreline project site. This is an ongoing endeavor in Georgia headed up by the Georgia Department of Natural Resources, the Nature Conservancy, and other academic and government partners.
The goal of this on-going project is two-fold: “To study the feasibility of alternative techniques to traditional shoreline hardening in tidal wetlands (i.e. alternatives to riprap and bulkheads), and to determine the effectiveness of alternative erosion control methods that will protect and enhance ecosystem function.“ http://coastalmanagement.noaa.gov/mystate/docs/ga3092011.pdf Creating a Living Shoreline, as opposed to a rigid concrete structure, which will provide a natural remedy for erosion occurring on intertidal banks as well as provide a much needed habitat for various marine life. The added vegetation will also stabilize the soil and complete the natural barrier. Additionally, the restored oyster reefs will improve the environment by providing habitat for fishes and be filtering water.
The Living Shoreline sites were restored via two primary methods. One way is through the use of mesh bags filled with oyster shells and arranged at one site in two layers along 370 feet along the creek bank. At another site they have placed Gabions, which are 6 feet by 12 feet, and house compartments made of chain linked steel then filled with a combination of bags of oyster shells, loose shells, and rock. This structure is used on steeper banks and the individual compartments prevent the shifting of the bags due to the sharp incline. The idea behind these are the same, the oyster shell provides a substrate for the oyster larvae or spat to adhere. After some experimentation, it was found that the calcium carbonate found on the inside of oyster shells provides the optimal surface for attachment. As oyster larvae attach, grow, and eventually die, this process repeats. This renews the oyster population, provides habitat for marine life, and prevents erosion as sediment builds up.
Our class helped monitor this process by using a method to assess vegetation and oyster recruitment along two of the banks. At several designated sites we laid three transects. By measuring from the top of the bank to the water line, we established a top, bottom, and middle location for our transects. In those transects we counted the number of both live and dead oysters, as well as, took note of the other species that may have been present. We then measured the length of 30 oysters to find an average size. For the vegetation, we found a mid-point and measured the percentage of different species such as Spartina, Distichlis, and Sea Oxeye Daisy. This protocol is done regularly at nine designated places at this site to monitor the progress being made. This project seems to be successful as recruitment has increased and the banks appear to be stabilizing.
This experience linked with class work as we were learning about the value, both direct and indirect, of environmental resources such as intertidal marshland. Marshes have a unique ability to assimilate nitrogen and other pollutants as well as offer flood protection. They also serve as a large source for food and industry. The seafood industry off coastal Georgia alone stands at an estimated 44 million dollars. However, the value of these environments is not just direct, the indirect benefits can be spiritual, recreational, or just the fact that a healthy environment seems to affect our individual health in a positive way.
Our class had learned about the Living Shoreline project before bagging shell at the GA DNR Coastal Resources Division; however, this trip seemed to tie the whole picture together. Everything from some of the planning done by the DNR, the bagging of the oyster shells, and the creation of a living shoreline, and finally the monitoring activities provides a clear picture of how a project like this is accomplished.
It was a beautiful day and the overall experience was entirely positive. I have found experiences like this help connect what we learn in the classroom to the practical real world application of what some of us may do in the field as biologists. It may also help to instill an appreciation for the environment as well as an understanding of its fragility.