**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**
and Sankar Subbayya
Applied Science Associates, Inc.
70 Dean Knauss Drive
Narragansett, RI 02882
Vermont Department of Fish and Wildlife contracted with Applied Science Associates Inc. (ASA) for a modeling study to assess the potential effects of applying the lampricide TFM (3-trifluouromethyl-4-nitrophenol) in the Missiquoi River and Bay to control sea lamprey larvae in the sediments. An existing hydrodynamic model of Missiosquoi Bay (Mendelsohn et al., 1997) was extended to include Missisquoi River and used to simulate the 12 hour input of TFM at the Swanton Dam (Figure 2) assuming, constant concentration, constant River discharge, and no decay of chemical.
Model predicted currents showed thatwinds dominate the currents in Missisquoi Bay and the currents in the river are mainly driven by the fresh water flow. The extent and duration of the TFM plume in Missisquoi Bay for a 12 hour input of the TFM at the Swanton Dam were predicted by the model for the 16 different combinations of water levels, river discharge, and TFM concentrations. The model predicted approximate time of travel of the leading edge of the TFM plume (defined as 50% of the concentration plateau) from the Swanton Dam application point to both Missisquoi and Dead Creek mouths were also estimated using the model.
Model predictions showed maximum extent and duration of the TFM plume for the 1500 cfs river flow cases and the TFM concentration for these cases reached below 20 ppb in 8 days. The concentration of TFM for the 500 cfs cases showed lesser spatial extent and duration than the 1500 cfs cases. The TFM concentrations for the 500 cfs cases reached below 10 ppb in approximately 6 days. The model predicted extent and duration of the concentration TFM plumes looked very similar for both the 95 ft and 97 ft lake water level cases.
The model-predicted approximate travel times for the leading edge of the TFM plumes, to the mouth of the Missisquoi ranged from 40 to 45 hours, and to the Dead Creek ranged between 21 to 23 hours, for 1500 cfs cases. The model-predicted travel times for the leading edge of the TFM plumes to the mouth of the Missisquoi ranged from 28 to 30 hours for the 500 cfs cases. The leading edge of the TFM plume did not get to the Dead Creek for the 500 cfs cases.