Harmful Algal Blooms
The Algal Ecology Laboratory (AEL) has continued to survey the statewide distribution and prevalence of Harmful Algal Blooms (HAB). AEL has a multi-institutional collaboration with:
- SC Department of Health and Environmental Control
- SC Sea Grant Consortium
- National Ocean Service of the National Oceanic and Atmospheric Administration
- University of South Carolina
- US Department of Agriculture’s Forest Service
- College of Charleston
- Medical University of South Carolina
to determine the distribution and causes of harmful algal blooms in SC waters, and their impacts on natural resources and human health. Program elements include research, monitoring, fish kill and bloom event response, identification of toxic effects on biological resources, public health evaluations, citizen volunteer monitoring, outreach, and mitigation.
Dr. Dianne Greenfield
The Algal Ecology Laboratory conducts an extensive coastal monitoring and event response program.. Our monitoring efforts have included nearly 50 sites statewide, ranging trom small man-made detention ponds to open estuaries. In FY 2004-05 we documented 52 algal blooms and 28 fish kills. Nine of those fish kills (32%) were associated with a HAB. Out of 70 total events (HABs plus fish kills) 14 were in direct response to a call received trom a property owner or community group. 80% of all HABs and fish kills in South Carolina were documented solely due to the monitoring efforts of the Algal Ecology Lab. In order to increase our response capabilities, we are establishing a network of real-time remote monitoring (RTRM) platforms. In FY 2004-05 we installed our fust RTRM unit in a brackish detention pond on Kiawah Island (http://www.ncsu.edu/wq/RTRMlkiawah/dp13cc.html).This unit allows us to monitor a suite of water quality and meteorological parameters trom our laboratory; giving us an accurate picture of what is happening in that pond 24 hours a day. The RTRM has a function that alerts us to any dangerous readings and triggers our bloom response unit. So far we have responded to 3 alarms trom the RTRM. As part of our ongoing efforts to improve our fish kill response efforts, the Algal Ecology Lab working with SCDNR veterinarian Al Segars, hosted South Carolina's fust Fish Kill Workshop. This workshop was given by veterinary pathologists trom Auburn University, and focused on tissue collection for pathology of finfish taken trom fish kills. This workshop was attended by personnel trom SCDNR Wildlife and Freshwater Fisheries, College of Charleston's Grice Marine Lab, and SCDNR Marine Resources Research Institute.
As part of our mandate to understand the causative agents of harmful algal blooms, we are investigating how bacteria and viruses affect algal blooms. We have identified and cultivated seven different bacterial strains that have either a positive or negative effect on the growth of harmful algal species. Weare currently testing extracts of these strains to isolate the specific chemical responsible for increasing or decreasing algal growth in the hopes that these compounds can prove useful for mitigation. We have also shown a defmite link between viruses and harmful algae in detention ponds on Kiawah Island, and are currently attempting to isolate some of these algal viruses.
The Algal Ecology Lab has a strong history of developing tools for the detection of harmful algal bloom species. In FY 2004-05, working closely with the SCDNR genomics group (headed by Robert Chapman), we developed a new detection tool that allows us to detect nine harmful algal species in a single test. We are currently working to automate this new technology using robotic equipment available through our partnership with the Hollings Marine Laboratory. Automation will increase our throughput from a couple of dozen to hundreds of samples in a day.
In addition to our efforts to understand the ecological and environmental implications of harmful algal blooms in South Carolina, the Algal Ecology Lab is also working to identify the effects of HABs on people and their companion animals. In fiscal year 2005-05 we began an epidemiological study to target HAB effects in companion animals. We have created a regional network of veterinarians who are on the lookout for symptoms of exposure to algal toxins in dogs and cats. We have provided information sheets to the vets to enable them to diagnose potential HAB symptoms. Additionally, we have put into place a mechanism to collect and track blood samples from potentially exposed pets in order to test for specific algal toxins. Although the program was created late in the fiscal year we have already had responses from several participating veterinarians.
In the rapidly urbanizing South Carolina coastal zone, intensive landscape maintenance and turf management are significant sources of nonpoint source pollutant loadings. The stormwater best management practice (BMP) of choice in this region is wet detention ponds, the majority of which are brackish lagoons. These highly eutrophic brackish ponds are "hot spots" for harmful algal blooms - over 200 blooms from 23 different species were documented over the last four years, many associated with measured toxins, fish kills or shellfish health effects. AEL personnel, through a SC Sea Grant-funded project, will test the use of constructed wetlands as a supplementary BMP to process stormwater and groundwater nutrients prior to entering detention ponds. Wetland construction is targeted for December 2005. Findings thus far from the baseline study include characterization of a 5-month long toxic Microcystis bloom, high denitrification potential in watershed soil and pond sediments and high nutrient fluxes into and out of the pond by stormwater and groundwater. Because these ponds exchange with tidal creeks, they are sources for harmful algal bloom dispersion into adjacent estuaries. These findings imply that manmade ponds as presently designed along the South Carolina coast may contribute to estuarine eutrophication and harmful algal bloom prevalence.
Laboratory and field studies were conducted in FY05 to assess the potential effects of HABs on shellfish habitats in Charleston Harbor and Kiawah Island. Increases in key protein biomarker responses were observed in oysters exposed to water collected during HAB events on Kiawah Island. Our research suggests that oysters are not only initially affected by toxic blooms, but may be bioaccumulating toxins.
The use of these oyster biomarker techniques in conjunction with the algal studies provide some of the first successful efforts to develop biological response indicators to determine the potential impacts of HABs on estuarine organisms.
The Algal Ecology Laboratory has established a link between invasive aquatic plants (primarily hydrilla) and associated epiphytic cyanobacteria species and Avian Vacuolar Myelinopathy (A VM). A new blue-green algal species that has been genetically characterized by the AEL lab covers up to 95% of the surface area of the leaves in the reservoirs affected by the disease. Collaborative experiments with Clemson University produced the disease experimentally by feeding hydrilla covered with the novel cyanobacteria to farm-raised mallards. Additional positive field and laboratory feeding studies using grass carp, mallards and chickens were conducted in November 2004. A VM brain lesions were noted for the first time in triploid grass carp (collaborative with Auburn University pathologist, Dr. John Grizzle). Our lab has coordinated additional surveys (52 total sites) in Florida, Georgia, North Carolina, Alabama, Mississippi and Texas to investigate the extent of this emerging disease. There are now 13 confirmed A VM sites within the southeastern United States.