**ABSTRACT NOT
FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract
for this completion report are provided below.
For a copy of the full completion report, please contact the author via
e-mail at thomas.pratt@dfo-mpo.gc.ca or via telephone
at 705-941-2667. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**
In Situ Assessment of Lampricide Toxicity to Age-0 Lake Sturgeon
T. C. Pratt2, L. M. O’Connor2, T.
B. Steeves3, B. Stephens3, M. Boogaard4, C.
Kaye5
2 DFO-GLLFAS 1219 Queen Ste.
East, Sault Ste. Marie, ON
3 DFO-SLCC 1219 Queen Ste.
East, Sault Ste. Marie, ON
4 USGS 2630 Fanta Reed Rd.,
La Crosse, WI
5 USFWS-SLCC 3090 Wright St.,
Marquette, MI
July 2013
ABSTRACT:
TFM and TFM/1 % niclosamide are selective lampricides used to control the Sea Lamprey (Petromyzon marinus), an invasive species in the Great
Lakes. Age-0 Lake Sturgeon (Acipenser fulvescens), listed as threatened or
endangered in both Canada and the United States, share similar stream habitats
with larval Sea Lampreys and these streams can be targeted for lampricide applications in the early summer months on a 3
to 5 year cycle. Previous studies found that, for Lake Sturgeon less than 100
mm, the concentrations required to kill 50% of Lake Sturgeon (Lethal
Concentration, LC50), and the Sea Lamprey Minimum Lethal Concentration (MLC, LC99.9)
concentrations were very similar and expected age-0 sturgeon mortality from lampricide application was high. We conducted stream-side
toxicity and in situ studies in
conjunction with lampricide applications during 2010
and 2011 to determine if the laboratory results concurred with subjective
observations during lampricide applications, namely,
that there was very little Lake
Sturgeon mortality in
stream settings. In the bioassays we found the observed LC50 for Lake Sturgeon
was higher than the predicted Sea Lamprey MLC. However, for two of the rivers,
the LC50 and MLC were very close. In situ,
we found that survival of Lake Sturgeon
less than 100mm total length during 10 lampricide
applications averaged approximately 80%, a rate that exceeds the laboratory
values.