Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021

Erindi/veggspjald / Talk/poster V33

Mapping and describing the Large benthic charr spawning sites of Thingvallavatn.

Höfundar / Authors: Helena Gylfadóttir, Quentin Horta-Lacueva, Sigríður Rut Franzdóttir, Kalina Kapralova

Starfsvettvangur / Affiliations: Háskóli Íslands

Kynnir / Presenter: Helena Gylfadóttir

The large benthic charr (LB) is one of the four morphs of Arctic charr (Salvelinus alpinus) endemic to Lake Thingvallavatn. The LB charr is believed to have evolved by utilizing cold water springs for spawning, which has been observed and described at only one location in the lake, thereby generating high conservation concerns. Yet, we have information from local fishermen and researchers about LB charr spawning in other areas of the lake. In this study, we plan to locate and confirm suspected spawning sites and describe their physical characteristics (notably considering the presence of cold-water springs). First, we will gather knowledge on potential spawning sites by interviewing stakeholders. Next, we will produce areal footage of the suspected site using drones to locate redds (i.e. Arctic charr nests appearing as spots cleared from algaes). Meanwhile, we will conduct snorkelling explorations to gather direct observation of LB charr, collect embryos and record physical data (temperature and depth). Then, we will test for the presence of spawning LB charr at the sampled sites through embryo staging (the LB charr suposedly spawning earlier than the other morphs) and genotyping. Finally, we will establish the distribution of LB charr spawning grounds across the lake by mapping the location of confirmed sites together with the collected physical data.