Genetics

Events such as the Big Bar Landslide can cause strong evolutionary shifts and affect the genetic diversity of affected populations. The selective pressure of these events may result in changes in the frequency of genetic variants that underlay adaptive phenotypes (e.g., run timing, swim performance). Widespread mortality and a decrease in population size following landslides can also lead to genetic bottlenecks and a subsequent reduction in the genetic diversity of salmon.

Current work

To assess whether specific genes are associated with the ability to successfully migrate past the Big Bar Landslide site, we have assembled an inventory of tissue samples from 2019 and 2020 radio-tagged Sockeye and Chinook salmon that both successed and failed to pass the Big Bar landslide. Following DNA extraction, the samples are currently being sequenced. We have identified key populations, from both above and below the Big Bar Landslide and from years unaffected (2016 - 2018, 2020) and affected (2019 - 2010) by the landslide, to assess how this event changed genetic diversity of Fraser salmon. We are currently acquiring these samples.