Vulnerability to predation could be mediated by:
Strain of brown trout
Stocking method
Time of stocking.
We chose to evaluate three strains of brown trout to determine whether there were
differences in post-stocking performance of these strains.
Later in the study we compared shoreline
stocking with offshore stocking.
During the course of the study, we learned that alewife abundance was
lowest in early spring and increased to peak levels as adult spawners entered
Thunder Bay in June.
Thus, the timing
of stocking during spring could effect subsequent survival.
For the study period, we stocked all
yearling brown trout during the June peak in alewife spawner abundance.
Pictured are mature Seeforellen (top) and Plymouth Rock (bottom) strain brown
trout at age 2.