With Drs. Allison Roy and Andrew Whiteley (UMass), and in collaboration with the Massachusetts Division of Marine Fisheries (MA DMF), we are investigating the productivity of river herring in lakes from Connecticut to Maine to determine the possible causes of variability. By employing different techniques to estimate productivity we determine the best (or most cost-effective) practices for continued monitoring. Methods include basic fisheries techniques, genetics, sonar and statistical modeling.