Battling a Common Enemy: The Service Works with Canadian Researchers
to Improve Sea Lamprey Management in the Great Lakes
For the past few summers, personnel from the U.S. Fish and Wildlife Service’s Sea Lamprey Control Program based at the Ludington Biological Station have partnered with researchers from Canada’s Wilfrid Laurier University in Waterloo, Ontario to work on an ongoing research project on lampricide resistance. Lampricide (3-trifluoromethyl-4-nitrophenol, abbreviated TFM) is a selective pesticide that has been used since the 1960’s to control sea lamprey, an invasive species in the Great Lakes. The project’s objective is to determine if the ability of larval sea lamprey to resist lampricide varies by season.
In the 2013 field season, graduate students Benjamin Hlina and Alexandra Muhametsafina conducted laboratory trials utilizing the facilities at the U.S. Geological Survey’s Hammond Bay Biological Station in Millersburg, Michigan. Service staff assisted with the on-going project by identifying streams with an abundance of larval sea lampreys and led the collection of lamprey, which provided thousands of larvae for the study.
The results of the study have confirmed what some researchers thought to be true, “we have observed increases in lampricide tolerance as stream water temperatures increase. We believe these trends may be caused by increases in larval sea lampreys’ capability to detoxify lampricide. Larger energy stores and increased metabolic rates could be contributing factors to seasonal changes to tolerance”, Hlina explained.
“We are currently assessing if the larval sea lampreys’ metabolism and detoxification of lampricide really does increase with increases in water temperature,” continued Hlina. Muhametsafina’s research builds upon this theme, examining both how TFM sensitivity varies seasonally and how and if larval sea lampreys recover after lampricide exposure at a wide range of water temperatures. “There is evidence to show that recovery after exposure to low concentrations of TFM is faster in warmer water,” said Muhametsafina.
Larval sea lampreys burrow into the stream bottom where they filter feed for 3-7 years before they metamorphose into a fish-eating parasite and migrate downstream to the Great Lakes. Similar to other fish species, sea lampreys are called poikilotherms in Greek which means (“cold-blooded”, and their activity level and metabolism are linked to water temperature. Researchers want to find out how this relationship works in order to improve sea lamprey management techniques.
Larval sea lamprey collection efforts for this project in 2013 focused on the Au Sable River, near Oscoda, Michigan. Service staff worked alongside researchers to collect larvae with backpack electrofishing units. The captured larvae were held in aerated tanks and transported to Hammond Bay Biological Station where they were placed in aquariums containing water that was the same temperature as their natal stream. After acclimating to the aquarium for a few days, the laboratory trials were conducted.
The research, which is funded by the Great Lakes Fishery Commission, could have management implications for TFM applications and sea lamprey management throughout the Great Lakes. “We hope our findings assist the Service and the Department of Fisheries and Oceans Canada in applying TFM during the most optimal times depending on seasonal differences,” said Hlina. “By understanding when the optimal application periods are, financial costs associated with TFM applications will potentially be reduced, local abundance of larval sea lamprey will be reduced resulting in adult sea lamprey population reduction, and the potential affects to non-target aquatic organisms will be reduced.” The hope is that this research will help the Sea Lamprey Control Program become more efficient and effective in lampricide application aimed at controlling this devastating invasive species.
Established in 1955, the Commission coordinates fisheries research, controls the invasive sea lamprey, and facilitates cooperative fishery management among the state, provincial, tribal, and federal management agencies in the Great Lakes. The Service delivers an integrated Sea Lamprey Control Program which works in partnership with the GLFC to restore and protect the Great Lakes ecosystem and a fishery with an estimated annual economic impact of $7 billion.
By Aaron Jubar