Lake Ontario Atlantic salmon
Theory suggests that to restore an extirpated population (a local population that no longer exists but other source populations of the species still exist in other areas), a source population that is genetically similar (ancestry match) has a higher success at restoration. However, another approach for the selection of a source population is to match the local environments between the extirpated and source populations (environment match). Environment matching may be particularly important when the environment of the extirpated population has changed substantially from the historical environment.
Lake Ontario Atlantic salmon (Salmo salar), a population extirpated by 1900, presents an ideal system to examine the performance of source populations that differ in the degree of ancestry matching and environment matching to important components of the altered environment. Important environment changes to Lake Ontario that are impediments to Atlantic salmon restoration include competition with non-native salmonids and a current diet of hihg thiaminase-containing prey fishes. Here, I will compare the performance of three populations of Atlantic salmon in experiments examining the effects of competition and thiaminase.
For more information on the Restoration Program and volunteering see:
source population selection
Restoration efforts can draw on several source populations using the following criteria:
Environment matching may be particularly effective when the environment of the extirpated population has changed substantially from the historical environment. Conceivably in such cases, environment matching (to the new conditions) will be more important than ancestry matching. Little, however, is known about the relative importance of ancestry versus environment matching in population restoration.
The source Atlantic salmon populations for reintroduction to Lake Ontario are:
Table 1: Summary of the Atlantic salmon source populations
Note: Competition and thiamine deficiency have been identified as impediments to the restoration of Atlantic salmon into Lake Ontario. Sebago Lake information is for fish stocked into Lake Champlain.
For more information on the choice of source populations see:
Houde ALS, Garner SR, Neff BD. 2015. Restoring species through reintroductions: strategies for source population selection. Restoration Ecology 23: 746-753.
Moritz C. 1999. Conservation units and translocations: strategies for conserving evolutionary processes. Hereditas 130: 217-228. doi: 10.1111/j.1601-5223.1999.00217.x.
Last updated January 2018
© Aimee Lee Houde