Water Chemistry of Great Lakes Tributaries, 2017-2018

Chemical composition of fish bones can be used to trace fish migrations and other movements (e.g., use of tributaries for spawning). Chemical composition of water is required to be able to trace fish migrations or movements to particular rivers or streams. Because water chemistry can change over time due to changes in land use, tectonic movements that alter groundwater pathways, pollution, industrial activity, and potentially other sources, periodic re-assessment of water chemistry is required. Here we present data on concentrations of common elements for several tributary streams to Lake Michigan, Lake Erie, and Lake Ontario collected in 2017 and 2018. These data will be useful to anyone desiring to track fish usage of these tributaries or changes in water chemistry resulting from land use changes.