The structure and functioning of Arctic ecosystems have been drastically modified by global warming, with fish species potentially performing habitat shifts such as the northern expansion of generalist and warm-adapted species. The freshwater fish species Arctic charr (Salvelinus alpinus, hereafter charr) plays a key role in Arctic lake food webs, but sticklebacks (Gasterosteus aculeatus) may impact the trophic position (TP) of charr by affecting their habitat choice and food resources. In the present study, we used multiple regression analyses to examine the role of lake morphology (i.e., depth and area) and the influence of sticklebacks on the TP of charr (estimated from δ15N and δ13C) sampled in nine Arctic lakes in Western Greenland between 2011 and 2013. Results showed that charr populations exhibited larger TP values when co-occurring with sticklebacks. Specifically, for larger and deeper lakes, a significant positive effect on TP values was observed for medium-sized (25 to 35 cm) charr. Moreover, the TP of sticklebacks had a null effect on the TP values of the largest charr (> 40 cm), suggesting that the largest-sized charr individuals did not prey on sticklebacks. We conclude that charr undergoes flexible ontogenetic trophic trajectories depending on the species composition of the Arctic fish community structure (here presence or absence of sticklebacks) and abiotic lake features.
ecosystem size food webs polar regions predator-prey interactions salmonids
We thank Anne Mette Poulsen, Kathe Møgelvang and Tinna Christensen for manuscript assistance and layout and the technical staff at Aarhus University for valuable support. The work was supported by the “Global Climate Change Programme” (no. 9700195) and the MARS project (Managing Aquatic ecosystems and water Resources under multiple Stress) funded under the 7th EU Framework Programme, Theme 6 (Environment including Climate Change), Contract No.: 603378 (http://www.mars-project.eu). Funding for the 2012 expedition to Greenland was provided by the Carlsberg Foundation (Project 2013_01_0535) and the Arctic Research Centre, AU. During the writing phase, EJ and TAD were supported by the North Water Project (NOW), funded by the Velux Foundations and the Carlsberg Foundation, and TLL was supported by the Arctic Research Centre, AU. EJ was also supported by Tübitak BIDEB 2232 (project 118C250). NM was supported by SNI-Uruguay. RFM was supported by the Coordination for the Improvement of Higher Educational Personnel (CAPES) under the Brazilian Postdoctoral National Program (PNPD- Nº 2304/2011).
Birincil Dil | İngilizce |
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Bölüm | Araştırma Makalesi |
Yazarlar | |
Yayımlanma Tarihi | 26 Ağustos 2022 |
Yayımlandığı Sayı | Yıl 2022Cilt: 8 Sayı: 2 |