Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E107
Höfundar / Authors: Camille A. Leblanc (1), Agnes-Katharina Kreiling (2), Krista Veijonen (1), Ragnhildur Guðmundsdóttir (3), Leivur Janus Hansen (2), Kári H. Arnasson (1), Bjarni K. Kristjánsson (1)
Starfsvettvangur / Affiliations: (1) Hólar University, (2) Faroe Islands National Museum, (3) Icelandic Museum of Natural History
Kynnir / Presenter: Camille Leblanc
How cold water lakes respond to warming and anthropogenic changes is of primary importance to better manage and conserve aquatic diversity and ecosystems functioning. One way to characterize changes and associated responses is achieved by comparing contemporary data to historical data, while using similar methodology. Here we revisited three small lakes in the Faroe Islands and assess communities of fishes and their prey 20 years after the NORLAKE project. We focus on Brown trout (BT) and Arctic charr (AC), studying fish phenotypes, life history traits and diet, as well as invertebrate communities. Water parameters were collected at sampling and temperature depth profiles captured with dataloggers between summers 2022 and 2023. The invertebrate communities in the lakes have changed between 2000 and 2022, both in composition and densities, resulting in changes in the prey availability for fishes. We detected a shift to a less diverse diet in BT, but not in AC. The overall number of fishes was higher now than in 2000, but the ratio between AC and BT in Leynavatn (the only lake with AC) has changed, with BT now being more numerous than AC. This shift in species composition should be taken into account for the conservation of the only native AC population in the Faroes. Finally, we discuss the relevance and opportunities in resampling aquatic systems to assess temporal changes in fish and invertebrates communities while capturing seasonal and annual environmental changes.