Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster E48

Behavioural differences among Icelandic stream salmonids: A brief overview

Höfundar / Authors: Stefán Ó. Steingrímsson (1), Benjamin I. Andrews (1,2), Tommi Linnansaari (2)

Starfsvettvangur / Affiliations: 1. Hólar University, 2. University of New Brunswick

Kynnir / Presenter: Stefán Óli Steingrímsson

Three salmonid species are native to Icelandic freshwater: Arctic charr, brown trout and Atlantic salmon. These species show clear differences in the habitat preference that shape their distribution within watersheds and at larger geographical scales. For example, within streams, Artic charr prefer slow-running waters, whereas brown trout and particularly Atlantic salmon use faster water currents. Similarly, at a larger scale, Arctic charr inhabit colder, less productive streams, than both brown trout and Atlantic salmon. To date, however, limited data are available on how individual behaviour shapes the distribution of these three fish species in space and time, and vice versa. In this presentation, we highlight recent findings on the foraging behaviour, territoriality and diel activity of these species in Icelandic streams. All three species feed mostly on invertebrates drifting in the water column. Arctic charr are more mobile while searching for prey than brown trout and Atlantic salmon, and use larger territories than brown trout. Moreover, temperature preferences of the three species are reflected in their diel activity patterns. Specifically, at 10°C Arctic charr spend a larger proportion of the 24h daily cycle feeding (89%) than both brown trout (17%) and Atlantic salmon (15%). We discuss how these behaviours give further insights into the distribution of salmonids in Icelandic streams.