Accession Number:

ADA235669

Title:

Characterization of Water Exchange in Hydrilla-Infested Tidal Canals of the Crystal River, Florida.

Descriptive Note:

Final rept.,

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS ENVIRONMENTAL LAB

Personal Author(s):

• Fox, Alison M.
• Haller, William T.
• Getsinger, Kurt D.
• Green, W. R.

Report Date:

1991-04-01

Pagination or Media Count:

52.0

Abstract:

The freshwater, tidal canals of the Crystal River, Florida, have been infested with hydrilla Hydrilla verticillata Royle for over two decades. The efficacy of herbicide application in this system has been unpredictable, often resulting in inconsistent hydrilla control. The objectives of this study were to compare the influence of tides, vegetation, and season on water exchange in dead-end canals and to evaluate herbicide efficacy in the canals as predicted by water exchange patterns. The fluorescent dye Rhodamine WT was used in four dead- end canals to estimate rates of water exchange and to characterize water movement during different tidal cycles. The behavior of the nonadsorptive dye indicated the maximum persistence of a chemical applied to the hydrilla-infested canals. The conditions under which dilution rates were slowest were identified. These conditions were predicted to be the optimum times for the application of herbicides, providing maximum herbicide exposure to the plants.

Descriptors:

• *AQUATIC PLANTS
• *WEED CONTROL
• *CANALS
• CYCLES
• FRESH WATER
• PATTERNS
• DYES
• RIVERS
• EXPOSURE(PHYSIOLOGY)
• VEGETATION
• FLUORESCENT DYES
• DILUTION
• EXCHANGE
• FLORIDA
• TIDEWATER
• HERBICIDES
• SEASONS
• TIDES
• CRYSTALS
• RATES
• OPTIMIZATION
• WATER

Subject Categories:

• Agronomy, Horticulture and Aquiculture
• Biology
• Hydrology, Limnology and Potamology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE