Natural streams

wild fry
Wild Atlantic salmon juveniles

Examining competition with non-native salmonids in a controlled laboratory setting (see Semi-natural streams) is informative as a primary indication of competition effects that may happen in the wild. However, the outcome of competition should also be examined in natural streams.


This study will examine the performance of three populations exposed to natural streams of Lake Ontario. Juvenile performance will be measured directly as survival and indirectly using measures that are related to the survival of Atlantic salmon.

Duffins Creek
Two natural stream sites were selected from Duffins Creek. The sites were similar in habitat features, with the exception of the presence of non-native salmonids, mostly rainbow trout. A barrier, a dam, has prevented the upstream movement of the non-native salmonids to one of the sites.

Juveniles (fry) were released at the sites in the spring and surviving juveniles were recaptured using the method of electrofishing in the fall and the next spring. Recaptured juveniles were measured for length and mass and had a small fin clip removed for DNA family assignment. Fish were released back to the site. Any non-native salmonids encountered were counted and immediately returned to the site.

The traits measured during the experiment are:


Houde ALS, Smith AD, Wilson CC, Peres-Neto PR, Neff BD. 2015. Competitive effects between rainbow trout and Atlantic salmon in natural and artificial streams. Ecology of Freshwater Fish 25: 248260. |PDF|



Research Projects

Pacific salmon
gene expression

Lake Ontario
Atlantic salmon



Last updated Januray 2018
© Aimee Lee Houde