**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**
Evaluation
of within stream lampricide distribution as a measure
of treatment effectiveness in controlling larval sea lampreys using enhanced
treatment regimes in Great Lakes tributaries
Upper Midwest
Environmental
August 2011
Abstract
We
evaluated stream concentrations of the lampricide
3-trifluoromethyl-4-nitrophenol (TFM) during six sea lamprey control treatments
to evaluate the use of enhanced treatment strategies with respect to the within
stream distribution of the lethal dose of TFM. TFM concentrations were monitored
at three sites within the treated area of each stream corresponding to a
straight section, a deep pool or bend, and an area of slack-water and/or extensive
aquatic vegetation. At each sampling
site, hourly water samples for TFM analysis were collected along longitudinal
transects of the stream from sampling locations spaced horizontally and
vertically within the water column.
Water chemistry analyses of pH, temperature, and alkalinity were also
measured hourly at each location within the sampling site. The enhanced concentration treatment
strategy (10% above normal treatment concentrations) applied to the Rifle, Bad,
and Manistique River systems achieved TFM concentrations of about 1.6 X the
predicted sea lamprey minimum lethal concentration (MLC) and ranged from 1.3 X to 2.0 X the MLC. Lampricide block
duration (length of time the treatment achieved TFM concentrations > sea
lamprey MLC) averaged 11.7 h and ranged from 10 to 13 h indicating TFM
concentrations were of sufficient magnitude and duration for effective control. The enhanced duration treatment strategy
applied to the Brule, Cedar, and Carp River systems achieved TFM concentrations
of about 1.2 X the predicted sea lamprey MLC and ranged from 1.0 X to 1.35 X
the MLC. Lampricide
block duration averaged 12.8 h and ranged from 11 to 14 h indicating TFM
concentrations were of sufficient magnitude and duration for effective
control. A comparison of TFM block
profiles from the sampling locations within each transect indicated that TFM
concentrations, for the most part, were evenly distributed throughout the water
column within 3 h of detection at all sampling sites on all six treatments
evaluated. There were a number of sites
where the stream banks required an additional 1 to 2 h to reach target
treatment concentrations compared to the middle of the stream. However, TFM concentrations were maintained
for 1 to 2 h longer along the stream banks indicating the overall block
duration did not differ between sampling locations within these sites.