This is from is for Lake Huron, but we can see why the Seneca strain is stocked in lake Ontario.
Lake trout from Seneca Lake, New York, were also included in the Lake Huron program in an attempt to
inject sea lamprey resistant strains into the system. Unlike their Great Lakes counterparts who quickly
succumbed to this parasite, lake trout in Seneca Lake have coexisted with sea lamprey for centuries.
Moreover, Seneca Lake strain fish had been successfully stocked in Lake Champlain, New York in the
early 1960s where they are reported to have survived and reproduced in the presence of sea lamprey. While
no details were provided, New York biologists attributed their survival to the possibility that either this
strain was less susceptible to attack or more resistant to sea lamprey predation.
http://www.fws.gov/midwest/alpena/docum ... -cwt05.pdf
Lake Trout Strain Program
Genetic strains - Historically, as many as 12 sub-populations or strains of lake trout stocks may have
inhabited Lake Huron, each reflecting various degrees of adaptation to their local environment. However,
with the exception of two remnant stocks in Georgian Bay, these variations have been lost forever.