From Top to Bottom: Investigating the Daily Migration of Fish and Their Prey in Lake Superior

Project Summary

Where fish and their prey go in Lake Superior on a daily basis remains unclear to scientists. This project proposes to measure the top-to-bottom (vertical) migration of prey fish, predatory fish, and an important zooplankton species, Mysis relicta, in western Lake Superior over various seasons. Researchers will conduct day and night surveys on the research vessel Blue Heron in the deep trench off Taconite Harbor (Schroeder, MN) in May through late September. They will also work with the US Geological Survey and their research vessel the Kiyi to conduct day and night bottom and midwater trawls for fish.

Through diet and growth studies on fish caught during the trawls, researchers will examine how energy flows through the food webs in these locations. They also hope to evaluate food web linkages between the deep and shallow habitats in the lake. Understanding these linkages and migration patterns will help natural resource agencies better manage commercially important fish species such as ciscoes, salmon, and lake trout.