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2016-2018 Research Projects: Sustainable Coastal Development and Economy

Project: Microplastic contamination in coastal South Carolina: Sources, trophic transfer and abundance in biota

Principal Investigators

Peter Van den Hurk, Ph.D.; Clemson University, Department of Biological Sciences
Charles Rice, Ph.D.; Clemson University, Department of Biological Sciences
John Weinstein, Ph.D.; The Citadel, Department of Biology

Project Number

R/ER-46

Research Description

Over the past two years, the S.C. Sea Grant Consortium has supported a survey of microplastic abundance in Charleston Harbor, South Carolina and Winyah Bay, South Carolina. This study indicated that microplastics are ubiquitous in these estuaries and that plastic particles have negative impact on estuarine invertebrates. Intertidal beaches in Charleston Harbor were found to have significantly higher levels of microplastics than beaches in Winyah Bay. The most common particles observed in both Charleston Harbor and Winyah Bay are black plastic fragments. The prevalence of these black plastic fragments in these two South Carolina estuaries is unique.

This project will extend the knowledge of microplastic contamination in coastal South Carolina by continuing study of microplastic contamination in Charleston Harbor and Winyah Bay. Specifically, the research will characterize the black plastic fragment debris from Charleston Harbor and Winyah Bay and the innate toxicity of black fragments to grass shrimp, copepods, and mummichogs. Additionally, the sources of microplastics in Charleston Harbor will be investigated. The results of this research will be used to generate a series of effect assessment relationships to quantitatively describe impacts of microplastics to three ecologically important estuarine species. This project will also train graduate students at the Citadel and Clemson University. Findings of the study will be shared with resource managers, the scientific community and the general public.

Research Results

Au, SA, CM Lee, JE Weinstein, P van den Hurk, SJ Klaine. “Trophic transfer of microplastics in aquatic ecosystems: identifying critical research needs .” Integrated Environmental Assessment and Management, 2017.

Gray, AD, and JE Weinstein. “Size and shape dependent effects of microplastic particles on adult daggerblade grass shrimp, Palaemonetes pugio .” Environmental Toxicology and Chemistry, 2017.

Gray, AD, H Wertz, RL Leads, JE Weinstein. “Microplastic in two South Carolina estuaries: occurrence, distribution, and composition .” Marine Pollution Bulletin, 2018.

Au, SA. “Toxicity of Microplastics to Aquatic Organisms .” Ph.D. diss., Clemson University, 2017.

Leads, RL. “Microplastic Debris in Charleston Harbor: Identifying Sources and Assessing Effects on Grass Shrimp (Palaemonetes pugio) Immune Function .” Master’s thesis, College of Charleston, 2018.

Contact for Questions

Peter Van den Hurk (pvdhurk@clemson.edu) or Charles Rice (cdrice@clemson.edu)

Project: Development and validation of a novel molecular tool to rapidly detect and quantify harmful algal blooms (habs) caused by cyanbacteria: Enhanced early warning to safeguard environmental and public health

Principal Investigators

Dianne Greenfield, Ph.D.; University of South Carolina, Belle W. Baruch Institute for Marine and Coastal Sciences
William Jones, Ph.D.; University of South Carolina, Arnold School for Public Health

Project Number

R/ER-47

Research Description

Incidences of harmful algal blooms (HABs) caused by blue-green algae, or cyanobacteria, are increasing globally, with consequences to environmental quality and public health. In coastal South Carolina, HABs are associated with 1 out of 4 fish kills. Microcystin, a toxin produced by the cyanobacteria species Microcystis aeruginosa, has been detected in stormwater ponds with close proximity to residential development. Traditional methods for identifying and quantifying HABs are labor and time-intensive and often lack the ability to distinguish between species. These methods are problematic for early warnings and management decisions. In light of the rapidly-expanding growth and development along the coast, and resulting construction of stormwater ponds in close association with humans, there is a human health need for the development of tools to improve the assessment and management these systems.

This project provides support for the development of a cost-effective molecular tool, sandwich hybridization assay (SHA), to detect and quantify cyanobacteria HABs for water quality management purposes. Sandwich hybridization assay uses DNA probes to detect RNA sequences specific to particular species, allowing identification and quantification of phytoplankton species that cause HABs. Researchers will develop and validate the specific DNA probes necessary to target the cyanobacteria M. aeruginosa. Once probes have been developed, the accuracy of the tool will be assessed by comparing molecular SHA results to a calibration standard derived from known concentrations of phytoplanktons. The laboratory validation results will be related to field samples from coastal waters in South Carolina to ensure accuracy when assessing environmental samples. The technology will be shared through workshops and peer-reviewed literature for enhancing end-user monitoring and early warning detection systems.

Research Results

Dearth, NM. “Development of a Sandwich Hybridization assay to identify and quantify the harmful cyanobacterium Microcystis. ” Master’s thesis, University of South Carolina, 2017.

Contact for Questions

Dianne Greenfield (dgreenfield@belle.baruch.sc.edu)

Project: Determining sedimentation rates in storm water ponds to improve life-cycle costs assessments associated with maintenance dredging

Principal Investigators

Erik Smith, Ph.D.; University of South Carolina, Belle W. Baruch Institute for Marine and Coastal Sciences
Claudia Benitez-Nelson, Ph.D.; University of South Carolina, Department of Earth and Ocean Science

Project Number

R/ER-48

Research Description

Stormwater ponds are the most common best management practice (BMP) for controlling runoff in coastal South Carolina. Ponds are frequently associated with residential developments. Dredging is the largest cost associated with the life-cycle maintenance of stormwater ponds and is often the responsibility of residential neighborhood Home Owners Associations. Direct estimates of sedimentation rates occurring in residential stormwater ponds typical of coastal South Carolina and a comprehensive understanding of what factors influence the variability of sedimentation rates among ponds are needed. The question of how pond functioning and nutrient removal efficacy may change over time has also been identified as a key research issue. Combining measurements of nutrient concentrations in pond sediments with estimates of sediment deposition rates over time will yield another means of assessing longer-term pond sediment removal capacity and also how removal capacity may vary as a function of total sediment accumulation and loss of pond volume over time.

The overall goal of the research is to provide quantitative and locally relevant estimates of pond sediment sources and accumulation rates to create information needed for pond owners to better anticipate and plan for maintenance dredging. A secondary goal is to increase current understanding of the integrated role of ponds in nutrient sequestration at the landscape scale. Specifically, researchers will determine sediment accumulation rates in a range of residential stormwater ponds in coastal South Carolina and quantify the relative contributions of internal and external sediment sources. Additionally, nutrient concentrations of pond sediments will be quantified with depth to investigate changes to pond function over time. Technical recommendations will be disseminated to regulatory agencies, municipal stormwater managers, public education providers, and the broader scientific community.

Research Results

Schroer, William. “Drivers of Sediment Accumulation and Nutrient Burial in Coastal South Carolina Residential Stormwater Detention Ponds .” Master’s thesis, University of South Carolina, 2017.

Schroer, William, Benitez-Nelson, Claudia R., Smith E., Ziolkowski L. Drivers of Sediment Accumulation and Nutrient Burial in Coastal Stormwater Detention Ponds, South Carolina, USA . Ecosystems, 2017.

Contact for Questions

Erik Smith (erik@belle.baruch.sc.edu)