Escaped aquaculture is a significant concern related to wild Atlantic salmon and their struggling population. Preventing escapes is crucial and fairly widely advocated for, but in order for it to be prioritized by larger companies, they need to be held accountable when escapes happen. Traceability of escaped aquaculture is essential in order for that to happen. The current standard for differentiating wild salmon and aquaculture salmon is usually genetic testing. This testing can be inefficient and expensive. By creating a simple way to quickly determine the origin of a fish, we can apply this method more frequently and consistently throughout Nova Scotia and beyond.
Determining the age of a fish through microscopic analysis of their scales is a commonly known and frequently used method in science today. Many fish (including salmon) go through known cycles in their life that increase or decrease their growth, adding what appear as differently spaced "rings" on their scales as they progress through their life cycle. This allows us to easily read scales for their age, similar to counting rings on a tree. For my project, I used the idea of growth patterns in fish scales and looked at it from another angle. Aquaculture fish and wild fish live vastly different lives, from the way they hunt, the weather they have to endure and other things that have to happen for them to survive. Aquaculture fish have easy lives in this sense, considering they do not have to do much to stay alive. This results in strongly contrasting DNA makeup, leading visibly different growth patterns. My hope is to refine a system outlining these differences that can be easily utilized by others and myself in order to determine the origin of a fish.