A1 Journal article (refereed)
Trophic ecology of piscivorous Arctic charr (Salvelinus alpinus (L.)) in subarctic lakes with contrasting food-web structures (2019)

Kahilainen, K.K., Hayden, B., & Eloranta, A. P. (2019). Trophic ecology of piscivorous Arctic charr (Salvelinus alpinus (L.)) in subarctic lakes with contrasting food-web structures. Hydrobiologia, 840(1), 227-243. https://doi.org/10.1007/s10750-018-3845-z

JYU authors or editors

Publication details

All authors or editors: Kahilainen, K. K., Thomas, S. M., Harrod, C.; Hayden, B.; Eloranta, A. P.

Journal or series: Hydrobiologia

ISSN: 0018-8158

eISSN: 1573-5117

Publication year: 2019

Volume: 840

Issue number: 1

Pages range: 227-243

Publisher: Springer

Publication country: Switzerland

Publication language: English

DOI: https://doi.org/10.1007/s10750-018-3845-z

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/66491

Abstract

The trophic ecology of piscivorous Arctic charr (Salvelinus alpinus (L.); charr) in the food webs of large subarctic lakes is not well understood. We assessed charr diets, parasites, growth, maturity, and stable isotope ratios in Fennoscandian subarctic lakes dominated by monomorphic or polymorphic whitefish (Coregonus lavaretus (L.)) populations. Charr density was low in all lakes, except in profundal habitats. Charr shifted to piscivory at small size (16–25 cm total length) and consumed a range of prey-fish sizes (2–25 cm). Cannibalism was observed in a few individuals from one monomorphic whitefish lake. Charr matured at 37–51 cm (5–8 years old), grew to 52–74 cm maximum observed length and 47–83 cm asymptotic length. Charr increased total area of convex hull and core stable isotopic diversity area of the fish community by 51–98% and 44–51% in monomorphic whitefish lakes, but only 8–11% and 7–10% in polymorphic whitefish lakes. The difference was due to increasing food-chain length in monomorphic whitefish lakes, whereas reliance on littoral carbon did not change. Charr were the top piscivores in monomorphic whitefish lakes, but played a less important role in polymorphic whitefish lakes, which contained a more diverse predator fauna.

Keywords: food chains; food webs; predation; arctic char; Coregonus lavaretus

Free keywords: diet; food-chain length; polymorphism; predation; stable isotopes, whitefish morphs

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 1