Research Project: Submerged Aquatic Vegetation Evaluation in Currituck Sound (SAVE Currituck Sound)

By Meghan Savona, First Flight High School Intern

Submerged aquatic vegetation (SAV) play an important role in coastal ecosystems.

Plants play an important role in both terrestrial and aquatic environments. Certain types of plants known as submerged aquatic vegetation (SAV) are especially important in helping to sustain life within our local marine, estuarine, and riverine environments. These flowering vascular plants play a key ecological, physical, and biogeochemical role in coastal waters. They help slow erosion, act as nurseries for juvenile fish, and facilitate the transfer and filtering of nutrients.

Because SAV are such an important part of our coastal ecosystem, it’s crucial to understand how different environmental factors aid and inhibit their growth. A new two-year project, Submerged Aquatic Vegetation Evaluation in Currituck Sound (SAVE Currituck Sound), is being conducted to evaluate current and historic change of SAV distribution and to relate SAV distribution to water-column and substrate parameters and physical processes.  The group will measure biological, chemical, and physical parameters at two study sites in the Currituck Sound to begin to understand the drivers of SAV distribution change with time.

SAVE Currituck Sound study areas

The project is funded by the North Carolina Department of Transportation (NCDOT) Research and Development program.  Understanding SAV distribution will allow NCDOT to better implement cost-effective SAV mitigation strategies and practices when working on water-dependent NCDOT projects. Data provided to NCDOT may help SAV mitigation strategies in oligohaline (low salinity) environments in the future.

Project lead Reide Corbett, graduate student Natasha Biarrieta and First Flight High School intern Kira Foster prepare to perform quadrat sampling along a transect. Quadrat sampling included percent SAV cover and species identification.

Dr. Reide Corbett, a senior level coastal marine chemist at CSI, will act as the project Principal Investigator and project lead. The project is a collaborative effort between Corbett and Dr. J.P. Walsh at CSI, Dr. Heidi Wadman and Patrick Dickhudt at the U.S. Army Corps of Engineers (USACE) Field Research Facility, and Mark Fonseca with Continental Shelf Associates, Inc. CSI will be responsible for placing transects and collecting sediment samples at each site and for analyzing samples and quantifying water column parameters. Eventually, CSI will be able to determine short-term changes in distribution associated with seasonal growth while aerial imagery will be used to assess long-term changes.

“DOT has active projects and current infrastructure across many oligohaline environments — low salinity environments — so this will benefit any potential mitigation strategy moving forward,” Dr. Corbett said.

Meteorological and water data from observing platforms in the Currituck Sound, installed and maintained by the USACE Field Research Facility will provide information on how environmental factors — waves, turbidity, salinity, etc. — affect SAV distribution. Data acquired regarding historic SAV distribution will be used to identify optimal locations for the establishment of approximately 15 SAV sampling sites, where SAV distribution fluctuation will be monitored long-term. These fixed sites will help inform NCDOT regarding key issues for mitigation and whether fluctuations in SAV presence is part of a natural rhythm or natural event or if it arises from human disturbances.

Erin Hodel, a research technician with Continental Shelf Associates, Inc. identifies SAV samples taken along transects.

“Broadly what we’re trying to do is understand the primary drivers of SAV distribution in the Currituck Sound, which has had significant change over the last three or four decades,” Dr. Corbett explained.