Great Lakes Fish Monitoring and Surveillance

Every year, fish are collected from each of the Great Lakes to support the Great Lakes Fish Monitoring and Surveillance Program. The whole fish samples are analyzed for different classes of contaminants. These analyses help EPA monitor long-term contaminant trends in Great Lakes top-predator fish.

This long-term monitoring program was established in the late 1970s and has collected top predator fish (lake trout and walleye) from consistent locations in each of the lakes in the fall of every year. Fish samples are collected in a target size range and subsequently aged prior to analysis to account for variation in growth rate and maintain high quality data.

GLFMSP data can be accessed via the Great Lakes Environmental Database.

View U.S. EPA GLFMSP Technical Report: Status and Trends through 2019 (pdf) for information.