Northern Prairie Wildlife Research Center (NPWRC) is investigating limitations to restoring abundant aquatic macroinvertebrate populations to Minnesota wetlands and shallow lakes. Recent research on larger more permanent wetlands in Minnesota indicates that there have been decreases in quality of wetlands of use by ducks. That research also describes a decline in abundance of amphipods, a shrimp-like Crustacean. Amphipods are important forage for ducks during spring migration because they are nutritious and can occur at very high densities. This research is focused on understanding what factors limit super abundance of amphipods in Minnesota wetlands. The work will examine limitations of amphipod dispersal and factors that reduce wetland quality (for example, invasive species, agricultural effects, pesticides, water quality). This study combines a large-scale observational study with laboratory toxicological experiments and a field experiment that involves stocking amphipods. This project began during January 2018 and is funded through 2021.