Temperature–growth patterns of individually tagged anadromous Arctic charr Salvelinus alpinusin Ungava and Labrador, Canada

• Published in: Ecology of Freshwater Fish
• Main Authors: Murdoch, Alyssa, Dempson, J. Brian, Martin, Francois, Power, Michael
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Arctic; Canada; Arctic charr
• Online Access: http://dx.doi.org/10.1111/eff.12133; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Feff.12133; https://onlinelibrary.wiley.com/doi/pdf/10.1111/eff.12133

Abstract Individual measurements of annual, or within‐season growth were determined from tag‐recaptured A rctic charr and examined in relation to summer sea surface temperatures and within‐season capture timing in the U ngava and L abrador regions of Eastern C anada. Differences between two years of growth (2010–2011) were significant for U ngava B ay A rctic charr, with growth being higher in the warmer year. Growth of L abrador A rctic charr did not vary significantly among years (1982–1985). Regional comparisons demonstrated that U ngava A rctic charr had significantly higher annual growth rates and experienced warmer temperatures than L abrador A rctic charr. The higher annual growth of U ngava B ay A rctic charr was attributed to the high sea surface temperatures experienced in 2010–2011 and the localised differences in nearshore productivity as compared to L abrador. Within‐season growth rates of L abrador A rctic charr peaked in J une, declined towards A ugust and were negatively correlated with the length of time spent at sea and mean experienced sea surface temperatures. A quadratic model relating growth rate to temperature best explained the pattern of within‐season growth. Collectively, results suggest that increases in water temperature may have profound consequences for Arctic charr growth in the C anadian sub‐ A rctic, depending on the responses of local marine productivity to those same temperature increases.