From Blue-Gray to Blue-Green:

Facilitating the Transition to Non-Plastic, Natural Material Use Within the Coastal Zone Economy

About the Project

The S.C. Sea Grant Consortium, in collaboration with the University of South Carolina, Clemson University, University of Dayton, Robinson Design Engineers, and Johnson C. Smith University, has launched the Blue Gray to Blue Green initiative.

The project aims to reduce coastal plastic debris by promoting the use of and researching natural materials that can replace plastic use in the growing sectors of coastal aquaculture, restoration, and water quality protection.

A Coastal Challenge: Marine Debris

Marine debris refers to any solid material created by humans that is intentionally or unintentionally discarded into coastal environments. Once marine debris enters the coastal environment, it breaks down into smaller fragments known as “microplastics” due to natural elements such as sun, wind, and waves. These microplastics are consumed by various marine animals, including birds, oysters, and fish.

Over time, these microplastics accumulate inside larger predators, including those that are important for commercial and recreational purposes. Plastics have been found in virtually all coastal habitats within coastal and estuarine ecosystems, including those in South Carolina and the southeastern U.S.

Coastal communities rely on salt marshes and seagrass beds to reduce wave energy and trap sediment. However, the coastal region is ecologically sensitive and a physically challenging environment that is also undergoing rapid economic and population growth. Coastal communities’ dependence on healthy ecosystems makes them vulnerable to plastic pollution.

Although the specific amount of plastic waste produced by the aquaculture, water quality protection, and shoreline restoration industries is unknown, evidence suggests that the use of plastics in these sectors can contribute to the deterioration of the ecosystems they aim to protect.

The figure below illustrates plastic use examples within the three sectors of the coastal economy impacted by our proposed project.

Examples of plastic used in the coastal aquaculture, restoration, and water quality protection sectors include floating treatment wetlands, geotextiles for erosion control, plastic oyster bags, styrofoam buoys, floating oyster cages, and anti-predator netting. Bruce Pfirrmann, University of South Carolina.

Project Plan

An Advisory Council has been established to include leaders within each of the three sectors and local community leaders. Council members are providing project guidance and direction to ensure project findings apply to and are usable by the broader coastal community. The Council is facilitated and coordinated by the S.C. Sea Grant Consortium.

The Advisory Council has representatives from the following entities: ACE Basin National Estuarine Research Reserve, Charleston County, Clemson University, Coastal Conservation League, Gullah Geechee Chamber of Commerce, Gullah Preservation Society, North Inlet Winyah Bay National Estuarine Research Reserve, S.C. Department of Natural Resources, SC Hemp Association, The Nature Conservancy, and the Town of Pawleys Island.

Coastal practitioners and stakeholders consider the physical characteristics of a material when selecting what material to use. To better understand how alternative (non-plastic) materials can withstand the coastal environment, materials will be tested in tanks, in a lab, and in the field.

• A suite of alternative materials will be tested in tanks at the Baruch Marine Field Laboratory. Students, faculty, and staff from Johnson C. Smith University will assist in these experiments as well.
• The University of Dayton’s Behavior of Advanced Material and Structures Laboratory will conduct further tests on alternative materials in a lab; they will control various environmental exposures including temperature, humidity, UV light, salinity, and surface abrasion. These experiments will help us understand the underlying conditions contributing to material failure.
• Field tests at the Baruch Marine Field Laboratory will occur on a narrower set of alternative materials based on which materials were successful in the lab and tank experiments.

In addition to the physical characteristics of a material, coastal practitioners and stakeholders often consider cost when selecting which materials to use. To assess this, Clemson University will conduct economic analyses on select materials to evaluate how feasible it would be for coastal sectors to adopt alternative materials.

All project results will be incorporated into resources and publications that highlight local knowledge from Gullah Geechee communities, expected suitable and unsuitable environments for natural material alternatives, and cost estimates of transitioning to new materials.

Funding and Partners

Funding award: National Sea Grant Infrastructure Investment and Jobs Act (IIJA) Marine Debris Challenge Competition

Start date: April 1, 2023

Project partners:

Dr. Bill Strosnider, Bruce W. Pfirrmann, Dr. Mariah Livernois – Baruch Marine Field Laboratory, University of South Carolina

Brooke Saari, Dr. Amanda Guthrie, Matt Gorstein, Dr. Susan Lovelace – S.C. Sea Grant Consortium

Dr. Michael Carbajales-Dale, Dr. Sarah White – Clemson University

Dr. Robert Lowe, Scott Schneider – University of Dayton

Dr. Mark Dugo – Johnson C. Smith University

Joshua Robinson – Robinson Design Engineers