Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributorUnited States. Bureau of Reclamation.-
dc.contributorUnited States. Army. Corps of Engineers. Seattle District.-
dc.contributorAquatic Plant Control Research Program (U.S.)-
dc.contributor.authorGetsinger, Kurt D.-
dc.contributor.authorSisneros, David.-
dc.contributor.authorTurner, E. Glenn.-
dc.creatorAScI Corporation-
dc.descriptionTechnical Report-
dc.descriptionAbstract: 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 μg/L through 7 days after deployment (DAD). Dye concentrations peaked at 105 to 130 μg/L at 2 DAD in Plot 1 (main channel plot) and 45 to 82 μg/L at 1 DAD in Plot 2 (side channel plot). When compared with herbicide concentration/exposure time relationships developed in separate laboratory experiments, results from these studies suggest that endothall, 2,4-D, and triclopyr are potential candidates for controlling Eurasian watermilfoil in selected locations in the Pend Oreille and Columbia Rivers. When using conventional, liquid herbicide application techniques in these rivers, treaunent sites should be a minimum of 4 ha in size. Results from the SRMD evaluations indicate that this slow-release carrier has potential for improving the control of Eurasian watermilfoil in high water-exchange environments, and a similar herbicide matrix should be evaluated in hydraulic channels and/or the field.-
dc.publisherEnvironmental Laboratory (U.S.)-
dc.publisherEngineer Research and Development Center (U.S.)-
dc.rightsApproved for public release; distribution is unlimited.-
dc.sourceThis Digital Resource was created from scans of the Print Resource-
dc.subjectEurasian watermilfoil-
dc.subjectRhodamine WT-
dc.subjectSubmersed plants-
dc.subjectAquatic plants-
dc.subjectWater exchange-
dc.subjectColumbia River-
dc.subjectPend Oreille River-
dc.titleUse of water exchange information to improve chemical control of eurasian watermilfoil in Pacific Northwest rivers-
Appears in Collections:Technical Report

Files in This Item:
File Description SizeFormat 
TR-A-93-1.pdf8.53 MBAdobe PDFThumbnail