Date of Award

Winter 2012

Project Type


Program or Major


Degree Name

Master of Science

First Advisor

W Huntting Howell


Opossum shrimp Mysis diluviana are an important trophic link in Lake Ontario, and in all of the lakes where they occur. Their temporal and spatial distributions are not well documented in the nearshore area (<30 m bottom depth), where alewives and other fish increasingly depend on them as a food source. This study describes their distributions over three years (2009 to 2011) from April through November using data collected from Tucker trawls and multi-frequency hydroacoustics; both deployed over incremental depths. Mysis was found to occur in the nearshore area in 69.6% of the trawl surveys. Maximum densities occurred in April and early May and were located in the deepest (30-m) contour. The density and frequency of occurrence of Mysis increased exponentially from shore. Hydroacoustic methods were effective in quantifying of Mysis density in 42% of the echograms when they were present in simultaneously obtained samples.