**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION.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 Gale.Bravener@dfo-mpo.gc.ca. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**
EVALUATION OF POST-SMRT EMBRYO
VIABILITY IN THE ST. MARYS RIVER
Gale Bravener1,
Jessica Barber2, Lisa Walter2
1Fisheries and Oceans
Canada, Sea Lamprey Control Centre, 1219 Queen Street East, Sault Ste. Marie,
ON. P6A 6N5
2Marquette Biological
Station, U.S. Fish and Wildlife Service, 3090 Wright Street, Marquette,
MI. 49855
3Great Lakes Fishery
Commission, 2100 Commonwealth Blvd., Suite 100, Ann Arbor, MI. 48105
December 2015
ABSTRACT:
A
sterile male release technique (SMRT), an alternative method for controlling sea
lampreys, was implemented in the St. Marys River
during 1991-2011 but concurrent treatments with the lampricide
granular Bayluscide largely confounded evaluation of
the technique during implementation. One
evaluation technique was assessment of sea lamprey nest success (egg viability)
in the St. Marys River rapids, which quantified the
reduction in survival at egg stage attributed to SMRT since embryos were not
affected by granular Bayluscide treatments. In this study, we conducted nest evaluations
for four years after SMRT was discontinued (2012-2015) using the same methods
used when SMRT was operational to test whether the post-SMRT embryo viabilities
were higher than embryo viabilities when SMRT was ongoing. We found that the post-SMRT viabilities were
significantly higher, suggesting that the original baseline viability of 43.4%
noted by Bergstedt et al. (2003) may have been
underestimated. This study provides
evidence that SMRT was likely reducing recruitment to the larval stage in the
St. Marys River, and corroborates previous work
showing that SMRT is effective at reducing reproduction. However, we did not
take into account the magnitude of the effect, nor the cost effectiveness of
SMRT compared to other control methods.