Assessing variations in blue carbon sequestration along a salinity gradient in tidal estuarine wetlands 

Mackenzie Taggart, Mariko Polk, and Devon Eulie

Tidal estuarine wetlands are an integral part of the global carbon cycle often functioning as long-term carbon sinks, efficiently sequestering atmospheric CO2 and carbon from surrounding ecosystems. As intertidal ecosystems, they have the ability to vertically increase surface elevation in pace with sea level rise—providing the potential for un-saturated blue carbon sequestration. Existing stores and further sequestration capabilities can diminish over time if a wetland is degraded—resulting in a transition from carbon sink, to source. It is critical to understand the extent of blue carbon stores across the Cape Fear Estuary and factors influencing sequestration in order to determine their vulnerability or persistence in the face of sea level rise. By understanding the Cape Fear River Estuaries role as a carbon sink, results from this study can aid in the development of environmental policies to mitigate impacts of sea level rise and ensure continued protection as a valued ecosystem for local, and global carbon cycling. 

Estuaries are an important ecosystem providing crucial habitat and possess the key ability to cycle nutrients and store carbon. Estuaries are often ecotones, the buffer between marine and terrestrial systems, providing developed areas with protection against large storm events. However, as climate change becomes a growing threat, rising sea level has become an increasing problem for many low-lying areas, including these essential estuarine systems. Erosion and anthropogenic modification of these areas can potentially alter the sediment accumulation and filling ability many estuaries rely on to keep pace with sea level fluctuation. Brunswick Town/Fort Anderson is a local historic site bordering the Cape Fear River that is experiencing high rates of shoreline loss, which is threatening the very survival of many historic plots and fortifications. Using gamma spectroscopy, we will be able to analyze 210 Pb and 137 Cs content of the sediment cores collected and calculate the sediment accumulation rates to identify depositional areas throughout the site. This will allow for prioritization of shoreline protection measures to be implemented at high-risk areas of the salt marsh. 

Investigating Marsh Grass Productivity and Carbon Storage through UAS and Remote Sensing Technologies

Allison Lapinsky, Mariko Polk, Devon Eulie, Martin Posey, Rachel Gittman, Mackenzie Taggart

What is this study looking to do? This study aims to investigate salt marsh vegetation health and blue carbon storage capacities along various living shorelines in coastal North Carolina while assessing the effectiveness of UAS and remote sensing technologies to do so. If successful, UAS monitoring could prove to be an easy and less destructive way to monitor coastal environments and living shoreline installments.  

North Carolina’s estuarine habitats provide a wide range of benefits from being nursery habitats to filtering water pollution, but are increasingly threatened by natural and human pressures. One of the greatest challenges for managing the coast is that drivers of habitat loss happen at different scales. For example, changes can be caused by short-term events, like hurricanes, or long-term from every day waves. A suite of options exist to manage erosion, such as hard bulkheads and nature-based living shorelines, but research comparing the various options and their broader impacts is limited. This study seeks to better understand how people and habitats are impacted based on the shoreline management project near them. This study combines science from multiple disciplines, through geospatial, emerging low-cost remote sensing and aerial mapping technologies, waterfront homeowner surveys, and citizen science. This study hopes to understand: 

1. Long-term patterns of shoreline and coastal habitat change 

2. Identify socio-ecological mechanisms responsible for shoreline and habitat changes

3. Test citizen science-based approaches for future shoreline monitoring

Resilience of North Carolina estuarine ecosystems is dependent upon coastal management decisions made now. The results of  this study will directly inform future coastal management, serve as a mechanism to educate homeowners on shoreline conservation and management strategies, and enable the development of long-term, cost-effective shoreline monitoring procedures that can be scaled up to state or region levels. 

Lead PI: Dr. Devon Eulie (UNCW)                  

Co-PI: Dr. Rachel Gittman (ECU)

Co-PI: Dr. Charles Peterson (UNC-CH)

 Dr. Carter Smith (Duke) 

Mariko Polk, PhD Student Alumni (UNCW)