TY - JOUR
T1 - Pelagic niche shift by fishes following restorations of a eutrophic lake
AU - Berthelsen, Andreas S.
AU - Søndergaard, Martin
AU - Kiljunen, Mikko
AU - Eloranta, Antti P.
AU - Lauridsen, Torben L.
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2025/1
Y1 - 2025/1
N2 - 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.
AB - 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.
KW - Biomanipulation
KW - Energy mobilization
KW - Lake management
KW - Stable isotope analysis
KW - Top-down control
UR - http://www.scopus.com/inward/record.url?scp=85195135562&partnerID=8YFLogxK
U2 - 10.1007/s10750-024-05568-5
DO - 10.1007/s10750-024-05568-5
M3 - Journal article
AN - SCOPUS:85195135562
SN - 0018-8158
VL - 852
SP - 289
EP - 303
JO - Hydrobiologia
JF - Hydrobiologia
IS - 2
ER -