HR: 15:45h
AN: NB24D-02    [Abstracts]
TI: Establishing Minimum Flow Requirements Based on Benthic Vegetation: What are Some Issues Related to Identifying Quantity of Inflow and Tools Used to Quantify Ecosystem Response?
AU: * Hunt, M J
EM: mhunt@sfwmd.gov
AF: South Florida Water Management District, Dept 4420 3301 Gun Club Road, West Palm Beach, FL 33406 United States
AU: Nuttle, W K
EM: wnuttle@eco-hydrology.com
AF: Consultant, 11 Craig Street, Ottawa, Ont K1S 4B6 Canada
AU: Cosby, B J
EM: B.J.Cosby@virginia.edu
AF: University of Virginia, Charlottesville, Department of Environmental Sciences Clark Hall PO Box 400123, Charlottesville, VA 22903 United States
AU: Marshall, F E
EM: fmarshall@ectinc.com
AF: Environmental Consulting & Technology, Inc., 340 North Causeway, New Smyrna Beach, FL 32169 United States
AB: Establishing minimum flow requirements in aquatic ecosystems is one way to stipulate controls on water withdrawals in a watershed. The basis of the determination is to identify the amount of flow needed to sustain a threshold ecological function. To develop minimum flow criteria an understanding of ecological response in relation to flow is essential. Several steps are needed including: (1) identification of important resources and ecological functions, (2) compilation of available information, (3) determination of historical conditions, (4) establishment of technical relationships between inflow and resources, and (5) identification of numeric criteria that reflect the threshold at which resources are harmed. The process is interdisciplinary requiring the integration of hydrologic and ecologic principles with quantitative assessments. The tools used quantify the ecological response and key questions related to how the quantity of flow influences the ecosystem are examined by comparing minimum flow determination in two different aquatic systems in South Florida. Each system is characterized by substantial hydrologic alteration. The first, the Caloosahatchee River is a riverine system, located on the southwest coast of Florida. The second, the Everglades- Florida Bay ecotone, is a wetland mangrove ecosystem, located on the southern tip of the Florida peninsula. In both cases freshwater submerged aquatic vegetation (Vallisneria americana or Ruppia maritima), located in areas of the saltwater- freshwater interface has been identified as a basis for minimum flow criteria. The integration of field studies, laboratory studies, and literature review was required. From this information we developed ecological modeling tools to quantify and predict plant growth in response to varying environmental variables. Coupled with hydrologic modeling tools questions relating to the quantity and timing of flow and ecological consequences in relation to normal variability are addressed.
DE: 1655 Water cycles (1836)
DE: 1851 Plant ecology
DE: 1860 Runoff and streamflow
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly