Mysis diluviana are an ecologically important migratory macroinvertebrate found in the Laurentian Great Lakes and other deep lakes in north America. Several studies have been conducted to understand their ecology and acoustic sampling characteristics. However, these have often been on a scale more local than a whole lake or focused on just one lake rather than comparing between lakes. I was able to leverage collaborators’ monitoring data to increase the scale at which parameters for population dynamics and acoustic properties could be studied. This increases our confidence about results at larger, more generally applicable scales of time and space. In Chapter 1, I estimated abundance, growth rate, mortality, reproduction, and secondary production of mysids across all of Lake Michigan during four seasons in 2015. We found that abundance and mysid production were relatively low in Lake Michigan in 2015. In Chapter 2, compared abundance trends over time, growth rates, fecundity rates, and mortality rates between all five Laurentian Great Lakes. We found that lakes ranked consistently across all vital rates (highest in Erie, followed by lakes Ontario, Michigan, Huron, and Superior). We also found that across all the lakes abundances were positively related to two food indices (zooplankton and chlorophyll) up to some threshold level after which values remained stable, although some lakes had lower values (likely due to predation). In Chapter 3, I report the acoustic material properties of mysids. I then applied a ray-based theoretical acoustic scattering model for mysids to in situ measurements from the Finger Lakes using the new parameter values. In Chapter 4, I use a large data set of paired acoustic-net data to examine the relationship between backscattering intensity and mysid abundance and to partition variability in TS according to size, lake, and vessel. I found that the relationships are significant and match theory, but individual site values vary greatly around the mean. TS was significantly related to vessel and mean size of mysids but not to lake, and much variability remained unexplained.