Evidence for Three Morphs of Arctic Char (Salvelinus alpinus) Present in the Marine Environment Off the Coast of Ulukhaktok, Northwest Territories, Canada

Standing

Undergraduate

Type of Proposal

Oral Research Presentation

Faculty

Faculty of Science

Faculty Sponsor

Dr. Nigel Hussey

Proposal

Alternative resource use and responses to environmental conditions can lead to phenotypic diversity and distinct morphotypes within many anadromous salmonids, including arctic char. Arctic char is a culturally and economically important subsistence resource in the Inuvialuit Settlement Region (ISR).The current study examined char’s morphological plasticity during their summer marine migration where local harvesters have noticed a decrease in small sized individuals, but where limited knowledge exists on char morphology and population mixing in the area. Morphometric analysis was conducted using digital photographs taken of live arctic char collected during marine migration-residency along the Ulukhaktok coast. Twenty-three landmarks were placed on digital images of 103 fish and used to investigate the presence of different morphotypes, followed by PCA and K-means analyses. The results categorized fish into three clusters based on distinctions in head and body shape; slender body and slim head (n=31), small and short head with a small mouth (n=46), elongated head shape with large mouth (n=26). These three morphs likely represent adaptation to specific feeding—movement behaviours, correlated with unique origin lakes. This study represents the first to identify arctic char morphs in the marine environment and identifies overlap in their habitat use during the marine phase with implications for differential resource extraction. The derived information can inform fisheries management in the ISR and Ulukhaktok on likelihood of overfishing specific phenotypes that could potentially reduce stock diversity, ensuring long term sustainability of the fishery.

Availability

March 30 (1-3pm), March 31 (1-3pm), April 1 (12-3pm)

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Evidence for Three Morphs of Arctic Char (Salvelinus alpinus) Present in the Marine Environment Off the Coast of Ulukhaktok, Northwest Territories, Canada

Alternative resource use and responses to environmental conditions can lead to phenotypic diversity and distinct morphotypes within many anadromous salmonids, including arctic char. Arctic char is a culturally and economically important subsistence resource in the Inuvialuit Settlement Region (ISR).The current study examined char’s morphological plasticity during their summer marine migration where local harvesters have noticed a decrease in small sized individuals, but where limited knowledge exists on char morphology and population mixing in the area. Morphometric analysis was conducted using digital photographs taken of live arctic char collected during marine migration-residency along the Ulukhaktok coast. Twenty-three landmarks were placed on digital images of 103 fish and used to investigate the presence of different morphotypes, followed by PCA and K-means analyses. The results categorized fish into three clusters based on distinctions in head and body shape; slender body and slim head (n=31), small and short head with a small mouth (n=46), elongated head shape with large mouth (n=26). These three morphs likely represent adaptation to specific feeding—movement behaviours, correlated with unique origin lakes. This study represents the first to identify arctic char morphs in the marine environment and identifies overlap in their habitat use during the marine phase with implications for differential resource extraction. The derived information can inform fisheries management in the ISR and Ulukhaktok on likelihood of overfishing specific phenotypes that could potentially reduce stock diversity, ensuring long term sustainability of the fishery.