Ecosystem restoration: Mysis re-introduction
The freshwater shrimp, Mysis diluvania, occupies many deep, stratified inland lakes on the boreal shield. It is a glacial relict species, and widely considered to be a “keystone” ecological species with regards to it’s effects in shaping zooplankton communities and promoting growth rates in fishes. However, it is highly sensitive to ecosystem change. During the acidification of lake 223 at the IISD-Experimental Lakes Area, Mysis were extirpated and never recolonized the lake. Lake trout in the lake display slower growth, higher mercury concentrations, and smaller population sizes since the extirpation of Mysis. We will evaluate (a) the record of extirpation of Mysis from the sediments of lake 223, as a means of determining the historical presence of Mysis in boreal lakes, and (b) propose to reintroduce Mysis to lake 223 as an ecosystem restoration measure, to determine if this action helps recover the lake trout population in lake 223.