MARINE, ESTUARINE, and TIDAL FRESHWATER ECOSYSTEM STUDIES

Strategic Goal 3: Enhance the availability and quality of marine, estuarine, and freshwater resources that can support the economic and quality-of-life needs of South Carolina's public and private sectors.

Continued interest in the marine and coastal environment is based primarily on its natural resource potential and economic value. Exploitation of the various resources available along the coast has led to increasing demand and competition for the right and access to those resources. Coupled with increased use—suburbanization, industrial development, agriculture, shipping, fishing, and recreation—impacts on the marine environment are inevitable. Encouraging harmony and fostering consensus among all users of the coastal and marine environment must be among the goals of managers responsible for ensuring the wise use and controlled development of the state’s natural resources.

The Consortium is committed to providing information and data to natural resource managers and stakeholders for use in minimizing and mitigating environmental effects resulting from these increasing pressures. A major area of concern has been identified by the Consortium—the study of estuarine systems—which for the last two decades has formed the basis for the Consortium’s ecosystem research portfolio.

To meet this goal, the Consortium has identified the following objectives for its ecosystems program:

1. Generate information on the effects of land uses and point and non-point source pollution on watersheds (coastal rivers, wetlands, estuaries) to improve the availability and application of such information among government decision makers, community organizations, and homeowners.

2. Develop and extend wetlands management (e.g., impoundments) strategies to encourage multi-species use and enhance water quality.

3. Develop information on the chronic and more subtle effects of pollutants on marine and estuarine resources.

4. Extend information management strategies to ameliorate impacts on water quality from non-point sources.

5. Examine the relationships between fisheries production in estuaries and the quality of habitat areas with particular emphasis on the relationships between the availability and utilization of food and vegetative cover and subsequent growth and mortality of the stock.

6. Determine the relationships between upland terrestrial ecosystems and estuarine productivity.

7. Identify species or suites of species that are indicative of specific levels of estuarine productivity or habitat quality.

Estuarine Studies

The Consortium is committed to providing information and data to natural resource users and managers for their use in minimizing and mitigating environmental effects resulting from these increasing pressures. The study of estuarine systems is a major area of interest for the Consortium, and has, for the last decade, formed the basis of the Consortium’s ecosystem dynamics program. The Consortium’s goal in this program area is to enhance the availability and quality of marine, estuarine, and freshwater resources that can support the economic and quality-of-life needs of South Carolina’s public and private sectors.

FY06-08 Priorities

For FY06-08, specific needs for Concept Letters include:

• Economic and social valuation research on coastal resources and ecosystem “services” (e.g., value of beaches to recreation and tourism or value of coastal wetlands as natural filters).

• Research that examines the interrelationships between coastal terrestrial (upland) ecosystems and estuarine productivity, as it may be influenced by land use change.

• Cutting-edge research to identify species or suites of species that can serve as first-order indicators of specific levels of estuarine productivity or habitat quality, for use in environmental assessments by natural resource management agencies.

• Investigations of the cumulative effects on key “indicator” marine organisms of low level, sub-chronic exposure to chemical contamination (from mixes of metals, organics, nutrients, antibiotics, pharmaceuticals) and/or physical changes (temperature, turbidity, hydrology) to the marine ecosystem due to increasing human activities.

• Examinations of the relationships between fisheries production in estuaries and the quality of habitat areas with particular emphasis on the relationships between the availability and utilization of food and vegetative cover and subsequent growth and mortality of the stock. The snapper-grouper complex and the red drum fishery have been identified for particular attention by fisheries managers.

• Concurrent studies on the interaction of physical, chemical, and biological forces that determine fisheries utilization of wetland/estuarine habitats, including an examination of the role of currents, tides, weather, and circulation patterns.

• State resource managers are confident that recent episodes of salt marsh die-off were related to the drought. However, research is needed to understand the mechanisms of the phenomena. For instance: What were the controlling mechanisms and processes? Were they related to ground water levels and movement? What are subsurface flows of ground water in the marsh? Is Spartina, particularly along tidal creek banks, dependent upon groundwater flow (where it was observed dying along tidal creek banks in a number of locations)?

• Aquatic invasive species are becoming a problem in coastal South Carolina. Outbreaks of Phragmites, beach vitex, and the spread of water hyacinth suggest that a concerted research and outreach effort is necessary to address these (and other coastal) invasives. Innovative research and outreach programs are needed.

Stormwater Management

Stormwater from urban and suburban environments is known to be a major contributor to the pollution loadings of the state’s rivers, marshes, and estuaries. The combination of the loss of “natural” vegetated areas and increased impervious cover has the potential to reduce natural stormwater treatment and increase polluted runoff, impairing waterways and affecting water quality. The nature of the quantity and quality of non-point source runoff determines the degree to which urban and suburban river and tidal creek ecosystems are affected. There is at present insufficient understanding of the efficacy and efficiency of many structural stormwater management systems in conditions typical of South Carolina. Efforts to capture key pollutants to control stormwater runoff do not necessarily match the needs of the receiving environments. The evaluation of existing stormwater management techniques is an important economic and environmental objective for Consortium research and outreach programming.

FY06-08 Priorities

For FY06-08, specific needs for Concept Letters in this area include:

• The development of stormwater quality treatment models based upon standardized protocols for monitoring and assessing the life cycle costs, functions, and performance of structural storm-water management practices in South Carolina is needed. In particular, research directly measuring the efficiencies and efficacy of stormwater BMPs are of interest.

• Research and demonstrations are needed on the effectiveness of vegetative buffers in the removal and transformation of stormwater pollutants (e.g., pesticides, herbicides, coliform bacteria, nutrients) and cost-effectiveness of designing and installing such systems, with recommendations for improvements. Research is particularly needed to assess the effectiveness of vegetated buffers in the coastal zone upon which appropriate buffer development criteria (e.g., size/width based on soil type, slope, ground cover/vegetative cover present, design or use in the buffer, and level of management of the buffer for removal of different pollutants or affording specific protections) can be identified. Some research does exist that provides results and recommendations that support the use of vegetative and/or riparian buffers, but the criteria for an effective buffer varies from community to community. While many agree that buffers serve as transition zones protecting adjoining surface waters from upland development areas and research findings indicate the need for buffer ordinances, there is no consensus regarding specific guidelines for buffer designs. In order to implement successful buffer ordinances communities need science-based information to support their decisions. Research should analyze and compare the costs of implementing these strategies, the efficiency rates of various types and sizes of buffers based on specific criteria, as well as addressing monitoring and maintenance issues.

• Likewise, similar investigations into the effectiveness of using vegetation in the removal and transformation of stormwater pollutants in constructed wetlands and grass swales, with recommendations for improvements, are needed.

• Research that improves understanding of non-structural storm-water management measures and how these measures may be incorporated into decision support systems.

• Research that quantifies the effectiveness of infiltration/adsorption systems for stormwater quality improvement, and includes evaluations of design parameters (such as hydraulic loading, infiltration media, depth of media) as they affect these systems in the coastal zone of South Carolina.

• Research that examines the long-term efficiency and effectiveness of stormwater retention ponds, and offers technical suggestions for improving pond performance and long-term maintenance (through restoration and renovation efforts). Some 8,000 (or more) stormwater detention and retention ponds have been constructed over the last three-four decades in coastal South Carolina to minimize the effects of non-point source runoff on adjacent coastal waters. While ponds have been designed to retain/detain a variety of chemical and biological constituents, there is little science-based information on their long-term effectiveness and efficiency in removing these materials, nor is there a requirement that they be regularly monitored and maintained.

• Programming to extend management strategies to ameliorate impacts on water quality from non-point sources, such as agriculture, golf courses, urban runoff, residential landscapes, and water dependent industries (marinas, docks, boat yards, etc.). The use of demonstration projects to test realistic solutions is encouraged.

Coastal Wetland Impoundments

The Consortium completed a large-scale multidisciplinary project to characterize the ecology of coastal wetland impoundments in South Carolina in the 1980s. The objectives of this research were to: (1) improve the understanding of how impoundments function ecologically, (2) recommend management practices that enhance impoundment productivity while minimizing environmental effects on adjacent areas, and (3) provide an ecological database to natural resource and regulatory agencies as they develop comprehensive impoundment policies and guidelines. More recently, the Consortium has supported additional research on coastal wetland impoundments in tidal freshwaters of the Cooper River.

While this research added significantly to the body of knowledge on wetland impoundment ecology, a number of questions remain to be answered, especially in light of the re-emergence of interest by impoundment owners seeking permission from the state for re-impoundment activities, and efforts by the state to craft a statewide impoundment management policy.

FY06-08 Priorities

The Consortium is interested in receiving Concept Letters that focus on the following:

• Under traditional management strategies, coastal wetland impoundments can significantly limit aquatic organism access and water exchange (important in maintaining optimal water quality conditions) between these systems and adjacent tidal waters. Sea Grant-sponsored research documented these conditions which led to the conclusion that additional research is needed to develop and test innovative impoundment management techniques (both structural and water management) which would alleviate impacts upon aquatic organisms and water quality while sustaining target organism production (e.g., water birds, shorebirds and waterfowl utilization).

• The quality of waters in and flushed from impoundments during a drawdown event, relative to the receiving waters, is an area requiring study. Parameters such as dissolved oxygen, BOD, TSS, pH, coliform levels, and nutrient loads need to be determined during impoundment flushing events, in a series of impoundments and adjacent tidal waters, to determine relative water quality conditions.

• Research is needed to examine breached brackish water impoundments in terms of their (a) DO range during the summer, (b) fish species (and invertebrate) utilization on a seasonal basis, (c) impact on river water DO, (d) identification and quantification of non-native plants and degree of exportation of these plants to the open river, (e) documentation of how water quality would change if the breached dikes were fixed and water management controls were re-established.

Strategic Goal 4

 

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