New Insights into Sea Lamprey Migration Patterns in Great Lakes

Researchers from Michigan State University (MSU) have made significant strides in understanding the migratory behavior of the sea lamprey, an invasive species threatening the Great Lakes ecosystem. In a study published in the *Journal of Experimental Biology*, a team led by Kandace Griffin, a doctoral student in Fisheries and Wildlife, and Michael Wagner, a professor in the same department, utilized acoustic telemetry to track the movements of 56 sea lampreys in the White River, located near Whitehall, Michigan.

The study revealed that nearly half of the tracked sea lampreys consistently preferred the deepest parts of the river, a behavior that could inform new management strategies for controlling this invasive species while also supporting the conservation of native fish populations. "We wanted to understand how sea lampreys make their movement decisions during migration," Griffin stated. "Understanding their preferences may allow us to manipulate these behaviors to guide them into traps."

The implications of this research are significant for the Great Lakes fishing industry, valued at approximately $7 billion and responsible for more than 75,000 jobs in the region. Current control methods primarily rely on the use of lampricide—a species-specific pesticide—and the construction of dams to block the fish's movement. However, as Wagner pointed out, these methods pose challenges for the conservation of river ecosystems, as they also restrict the migration of other fish species.

The research team employed acoustic telemetry, which involves surgically implanting tags that emit unique sound signals. These signals help track the fish's location, similar to a GPS system. Out of the 56 lampreys monitored, 26 were found to predominantly utilize the river’s deepest quarter. This finding suggests that the knowledge of their migratory paths can be instrumental in optimizing trapping locations across the Great Lakes.

The research aligns with ongoing efforts to develop alternative control methods that respect both ecological integrity and community concerns. Wagner emphasized the importance of collaboration with Indigenous communities who have traditionally fished migratory lamprey species. "We aim to integrate traditional ecological knowledge with our scientific findings to create effective fishing devices for sea lampreys," he said.

Both Griffin and Wagner believe that the insights gained from this study could lead to a supplemental control method that could work in conjunction with existing barriers and ecological goals. Their intention is to provide comprehensive solutions that will allow for effective management of the invasive sea lamprey while maintaining river connectivity for native fish species.

In summary, the research conducted by Michigan State University not only sheds light on the migratory patterns of sea lampreys but also opens new avenues for managing invasive species in a way that benefits both the ecosystem and the local fishing industry. As the Great Lakes face ongoing ecological challenges, such innovative research could prove vital in preserving the region's biodiversity and economic viability.