MSc in Environmental Sciences thesis defence by Carissa Grove
Presenter: Carissa Grove
Location: AVC 205N
Date/time: December 9, 2024, 2:00 pm
Title: 鈥淧opulation Genetics and Return Migration Behaviour of Atlantic Salmon (Salmo Salar) In Prince Edward Island, Canada鈥�
Atlantic salmon (Salmo salar) are declining across their native range where many populations in eastern Canada are threatened or endangered. In order to facilitate population recovery, widespread stocking has occurred throughout the region with over 37 million Atlantic salmon being stocked in Prince Edward Island (PEI) rivers since 1880. There is now evidence that stocking may put local genetic integrity at risk and impacts local adaptation on a population scale. A previous study identified two genetic populations on PEI, one unique to PEI and the other similar to other Gulf of St. Lawrence populations. In Chapter 2 of this thesis, we evaluated 884 individuals from 20 rivers on PEI known to contain Atlantic salmon. A panel of six microsatellites and next-generation sequencing were used followed by Bayesian clustering methods to infer groupings of populations. Generally, we see three major groupings on PEI including northeastern, southern, and northwestern to central draining rivers. Stocking intensity was not a good predictor for genetic variation. There are multiple genetic stocks on PEI that may be reflective of post-glacial colonization and local adaption. Upstream migration varies among and within rivers due to local conditions and genotypic differences. In order to assess migration behaviour, Chapter 3 evaluated the upstream migration of adult Atlantic salmon in North Lake Creek (NLC). Returning Atlantic salmon were caught and tagged with passive integrated transponders (PIT). Arrays were set up on multiple locations on NLC as well as adjacent rivers. Other morphometrics were taken at time of capture and environmental variables measured to determine what other factors influence movement. Individual fish detection was significantly associated with increased flows and decreased temperature. Additionally, time spent in the river averaged (SEM,n) 27.6 days (7.18, 10), meaning they stay in the river for a short period of time to spawn and leave to over-winter in the estuary or back to the ocean. The upstream migration of returning Atlantic salmon is complex and still being evaluated and understood however, it is important to evaluate these variances in light of genetic differences since it has been shown to play a role in timing.
Everyone is welcome.
