Arctic seals as tracers of environmental and ecological change

• Published in: Global Biogeochemical Cycles
• Main Authors: de la Vega, Camille, Mahaffey, Claire, Tuerena, Robyn E, Yurkowski, David J, Ferguson, Steven H, Stenson, Garry B, Nordøy, Erling S, Haug, Tore, Biuw, Martin, Smout, Sophie, Hopkins, Jo, Tagliabue, Alessandro, Jeffreys, Rachel M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2021
• Subjects: Arctic
• Online Access: https://livrepository.liverpool.ac.uk/3107242/; https://doi.org/10.1002/lol2.10176; https://livrepository.liverpool.ac.uk/3107242/1/lol2.10176.pdf

<jats:title>Abstract</jats:title><jats:p>Knowledge of species trophic position (TP) is an essential component of ecosystem management. Determining TP from stable nitrogen isotopes (δ<jats:sup>15</jats:sup>N) in predators requires understanding how these tracers vary across environments and how they relate to predator isotope composition. We used two seal species as a model for determining TP across large spatial scales in the Arctic. δ<jats:sup>15</jats:sup>N in seawater nitrate (δ<jats:sup>15</jats:sup>N<jats:sub>NO3</jats:sub>) and seal muscle amino acids (δ<jats:sup>15</jats:sup>N<jats:sub>AA</jats:sub>) were determined to independently characterize the base of the food web and the TP of harp and ringed seals, demonstrating a direct link between δ<jats:sup>15</jats:sup>N<jats:sub>NO3</jats:sub> and δ<jats:sup>15</jats:sup>N<jats:sub>AA</jats:sub>. Our results show that the spatial variation in δ<jats:sup>15</jats:sup>N<jats:sub>AA</jats:sub> in seals reflects the δ<jats:sup>15</jats:sup>N<jats:sub>NO3</jats:sub> end members in Pacific vs. Atlantic waters. This study provides a reference for best practice on accurate comparison of TP in predators and as such, provides a framework to assess the impact of environmental and human‐induced changes on ecosystems at pan‐Arctic scales.</jats:p>