Publication Date
Fall 2023
Disciplines
Physical Sciences and Mathematics
Recommended Citation
Cross, Annamarie, "A not-so-stable environment: An assessment of stable isotopic niches of the non-native European flounder and native salmonids in the Westfjords, Iceland" (2023). Iceland: Climate Change and The Arctic. 7.
https://digitalcollections.sit.edu/icc2/7
Comments
Arctic amplification ratios and climate models indicate that warming in the Arctic has been more pronounced since the late 1970s than the rest of the globe. As ocean temperatures continue to increase, southern species are expanding their distributional ranges northward, invading sub-Arctic and Arctic marine ecosystems, resulting in local consequences for native fish population. Iceland is currently experiencing a shift in its fish populations. European flounder (Platichthys flesus) is a recent arrival into the country’s marine ecosystem, but minimal research has been dedicated towards studying their invasive potential. This study uses statistical analysis software packages to calculate isotopic niche width and niche overlap between potentially invasive European flounder and two native salmonids, Arctic charr and brown trout, sampled in 2017, 2021, and 2022 in Iceland. Niche overlap was highest (63.82%) for flounder 2021/2022 and salmonid 2017 scale samples, suggesting trophic niche divergence. Salmonid sampled from 2017, and 2021/2022 had the largest niche width (7.71 and 6.50) while flounder had the smallest niche width (3.28). This paper suggests a lack of competition between flounder and salmonids but proposes increased competition between salmonids as a result of flounder’s recent invasion. Variations between length and stable isotope values were also calculated, but only select samples were significant. Improved research and monitoring of European flounder is important for the future of Iceland’s marine ecosystem.