Use of water exchange information to improve chemical control of eurasian watermilfoil in Pacific Northwest rivers. Final report

Technical Report · Fri Jan 01 00:00:00 EST 1993

OSTI ID:6434546

Getsinger, K D; Sisneros, D; Tumer, E G

The submersed plant Eurasian watermilfoil (Myriophyllum spicatum L.), continues to adversely impact areas in the high water exchange environment of the Columbia River system. Studies designed to characterize water movement and to evaluate a slow release matrix device (SRMD) for improving the chemical control of that target plant were conducted in the Pend Oreille and Columbia Rivers, Washington, in August 1990. A series of rhodamine WT dye treatments were applied (using conventional, liquid application techniques) to 4-ha plots representing milfoil-dominated riverine and cove sites to estimate potential herbicide contact time. In addition, dye-impregnated SRMDs were deployed in 0.4-ha plots and evaluated for their potential as slow-release herbicide carriers. Dye dissipation data were used to calculate water-exchange half-lives in plots treated with conventional application techniques. Mean half-lives ranged from 8.8 to 12.2 hr in riverine plots, to 36.3 hr in a plot situated in a protected embayment. Half-lives from these 4-ha plots were two to four times longer than half-lives measured in smaller plots (0.4 ha) from previous dye studies conducted in similar locations. In most cases, dye release rates from SRMDs provided water concentrations near the target level of 10 micrograms/L through 7 days after deployment (DAD). Dye concentrations peaked at 105 to 130 micrograms/L at 2 DAD in Plot I (main channel plot) and 4.5 to 82 micrograms/L at I DAD in Plot 2 (side channel plot).

• Research Organization: Army Engineer Waterways Experiment Station, Vicksburg, MS (United States). Environmental Lab.
• OSTI ID: 6434546
• Report Number(s): AD-A-262302/3/XAB; WES/TR-A-93-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
HERBICIDES
CONTROL
PLANTS
ENVIRONMENTAL EFFECTS
AQUATIC ECOSYSTEMS
BIOLOGY
BOTANY
CALCULATION METHODS
CARRIERS
CHEMISTRY
COLUMBIA RIVER
DYES
MATRIX MATERIALS
PACIFIC OCEAN
PLANNING
PROBABILISTIC ESTIMATION
WASHINGTON
WATER POLLUTION
WATER USE
DEVELOPED COUNTRIES
ECOSYSTEMS
MATERIALS
NORTH AMERICA
PESTICIDES
POLLUTION
RIVERS
SEAS
STREAMS
SURFACE WATERS
USA
540350* - Environment
Aquatic- Site Resource & Use Studies- (1990-)