What’s the Attraction?
Understanding the Movements of Sea Lampreys
Tiffany Opalka-Myers, Biological Science Technician, extracting pheromone from water samples. Photo by Sara Ruiter/USFWS.
By Sara Ruiter
Marquette Biological Station
Sea lampreys are attracted to certain rivers, but are they also attracted to rivers populated with the scent of native lampreys? This summer, personnel from the Marquette Biological Station collected water samples from five rivers to determine pheromone concentrations of sea and native lampreys present in the stream water before and after lampricide treatments.
Pheromones are chemical compounds released from an animal that can influence the behavior of other animals of the same species. When sea lampreys are present in a river they release two types of pheromones, a migratory pheromone that attracts lampreys to a specific river and a mating pheromone that attracts lampreys to one another. Native lampreys and sea lampreys have very similar pheromone composition and it is believed that a sea and native lamprey can be attracted to each other’s pheromones.
To better understand how sea lampreys respond to native lamprey pheromones, water samples were collected and pheromones were extracted from five rivers plus two controls streams for this pilot study. The rivers sampled include, the Black Mallard River on Lake Huron with the Ocqueoc River as the control stream, and the Sand and Carp Rivers on Lake Superior, with the Anna River as the control stream.
Two water samples were taken from the mouth, an intermediate point along the river, and above the lampricide primary application point for the Black Mallard, Sand and Carp Rivers.
Lampricide is a chemical used to kill juvenile sea lampreys before they become parasitic adults. Water samples were collected prior to the river being treated with lampricide, just after the treatment, and approximately 30 days after the treatment. Two water samples were also collected at the two control streams at the same times.
Harlow Creek on Lake Superior and Ocqueoc River on Lake Huron are the two rivers where temporal sampling took place. At each site two water samples are collected every six hours within a 24 hour period. These water samples were collected from the same location every month to look at the change in pheromone concentrations over time.
The project is currently ongoing. Water samples have been collected from all lampricide treated streams and all pheromones have been extracted from the water samples and are now awaiting analysis at Michigan State University.
Sara Ruiter, Biological Science Technician, collecting water samples from the Carp River. Photo by USFWS.