Potential for ecological effects and gene flow resulting from growth hormone transgenic Atlantic salmon (Salmo salar) interactions with wild conspecifics

• Main Author: Moreau, Darek T. R.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2011
• Subjects: Atlantic salmon; Salmo salar
• Online Access: https://research.library.mun.ca/11076/; https://research.library.mun.ca/11076/1/Moreau_DarekThomasRheal.pdf

Growth hormone (GH) transgenic Atlantic salmon (Salmo salar) exhibit tremendous growth rates under hatchery conditions. This phenotypic response has created interest within the aquaculture industry; however, possible escapee events have raised concerns regarding their potential ecological impacts. This thesis applied an eco-evolutionary approach to empirically assess the potential ecological effects of GH transgenic Atlantic salmon on non-transgenic intraspecific populations. Specifically, my goal was to explore the relative survival and reproductive success of GH transgenic and non-transgenic salmon under near-natural conditions. To accomplish this, key fitness-related traits were compared between GH transgenic and non-transgenic Atlantic salmon over periods of their life cycle when natural selection is typically intense. Specifically, this thesis focused on the young-of-the-year stream and the breeding periods. -- Two studies (Chapters 2 and 3) compared fitness-related traits between transgenic and non-transgenic Atlantic salmon during early life history. Chapter two explored the potential differences in developmental rate and respiratory metabolism between transgenic and non-transgenic siblings at three early stages of life; the eyed-embryo, alevin (larval) and first-feeding fry (juvenile) stages. Chapter three explored the foraging behaviour and the growth and survival of transgenic and non-transgenic first-feeding fry reared under low feed, stream-like conditions. Collectively, the result of these chapters suggest that there is an ontogenetic delay in the phenotypic response induced by the transgene, such that biologically significant differences in fitness-related traits between GH transgenic and non-transgenic Atlantic salmon are minimal during this critical early life history period. -- The final two studies (Chapters 4 and 5) compared fitness-related traits between transgenic and non-transgenic Atlantic salmon during the reproductive phase of the life cycle. The fourth chapter compared the breeding ...