A1 Journal article (refereed)
Pelagic niche shift by fishes following restorations of a eutrophic lake (2024)

Berthelsen, A. S., Søndergaard, M., Kiljunen, M., Eloranta, A. P., & Lauridsen, T. L. (2024). Pelagic niche shift by fishes following restorations of a eutrophic lake. Hydrobiologia, Early online. https://doi.org/10.1007/s10750-024-05568-5

JYU authors or editors

Kiljunen, Mikko
Eloranta, Antti

Publication details

All authors or editors: Berthelsen, Andreas S.; Søndergaard, Martin; Kiljunen, Mikko; Eloranta, Antti P.; Lauridsen, Torben L.

Journal or series: Hydrobiologia

ISSN: 0018-8158

eISSN: 1573-5117

Publication year: 2024

Publication date: 30/05/2024

Volume: Early online

Publisher: Springer

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1007/s10750-024-05568-5

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/95473

Abstract

Lake restoration by biomanipulation or phosphorus fixation has been commonly applied methods to improve the ecological status of lakes. However, the effects of lake restoration on food-web dynamics are still poorly understood, especially when biomanipulation and nutrient fixation are used simultaneously. This study investigated the combined effects of a 70% fish removal (mainly roach (Rutilus rutilus Linnaeus, 1758) and bream (Abramis brama Linnaeus, 1758) and Phoslock® treatment on fish trophic ecology in Lyngsø (area: 9.6 ha, mean depth: 2.6 m), Denmark. The lake restoration resulted in decreased nutrient levels, increased water clarity, and increased coverage of more structurally complex submerged macrophytes. Following lake restoration, significant changes in diets of the dominant fish species were observed. Stomach content analyses of roach and perch (Perca fluviatilis Linnaeus, 1758) revealed significantly reduced detritus utilization and increased foraging on macrophytes and macrophyte living invertebrates. Results from stable isotope mixing models indicated a shift from littoral benthic to more pelagic food resources by the dominant fish species. Our findings provide further evidence that lake restorations can lead to substantial changes in lake food webs and fish communities, thereby potentially facilitating a shift toward an ecological state resembling the pristine reference state, less influenced by anthropogenic factors.

Keywords: biomanipulation; lakes; water systems; environmental rehabilitation; water quality; eutrophication; restoration of water systems