title: Temperature-associated habitat selection in a cold-water marine fish.
abstract: Habitat selection is a complex process, which involves behavioural decisions guided by the multiple needs and constraints faced by individuals. Climate-induced changes in environmental conditions may alter those trade-offs and resulting habitat use patterns. In this study, we investigated the effect of sea temperature on habitat selection and habitat use of acoustically tagged Atlantic cod (Gadus morhua) at the Norwegian Skagerrak coast. Significant relationships between ocean temperature and habitat selection and use were found. Under favourable sea temperature thresholds (<16 °C), cod selected vegetated habitats, such as eelgrass and macroalgae beds, available in shallow areas. Selection for those habitats was especially high at night, when cod tended to ascend to shallower areas, presumably to feed. Selection and use of those habitats decreased significantly as temperature rose. Under increased sea surface temperature conditions, cod were absent from vegetated shallow habitats, both during the day and night, and selected instead non-vegetated rocky bottoms and sand habitats, available in deeper, colder areas. This study shows the dynamic nature of habitat selection and strongly suggests that cod in this region have to trade off food availability against favourable temperature conditions. Future increases in ocean temperature are expected to further influence the spatial behaviour of marine fish, potentially affecting individual fitness and population dynamics.
authors.affiliation: Centre for Coastal Research (CCR), Department of Natural Sciences, University of Agder, Post Box 422, Kristiansand, 4604, Norway.|Institute of Marine Research, His, 4817, Norway.|Centre of Marine and Environmental Research of Madeira (CIIMAR-Madeira), Edif. Madeira Tecnopolo, Caminho da Penteada, Funchal, 9020-105, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Freitas
authors.affiliation: Centre for Coastal Research (CCR), Department of Natural Sciences, University of Agder, Post Box 422, Kristiansand, 4604, Norway.|Institute of Marine Research, His, 4817, Norway.|Centre for Ecological and Evolutionary Syntheses (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, Oslo, 0316, Norway.
authors.forename: Esben M
authors.initials: EM
authors.lastname: Olsen
authors.affiliation: Centre for Coastal Research (CCR), Department of Natural Sciences, University of Agder, Post Box 422, Kristiansand, 4604, Norway.|Institute of Marine Research, His, 4817, Norway.|Centre for Ecological and Evolutionary Syntheses (CEES), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, Oslo, 0316, Norway.
authors.forename: Halvor
authors.initials: H
authors.lastname: Knutsen
authors.affiliation: Institute of Marine Research, His, 4817, Norway.
authors.forename: Jon
authors.initials: J
authors.lastname: Albretsen
authors.affiliation: Centre for Coastal Research (CCR), Department of Natural Sciences, University of Agder, Post Box 422, Kristiansand, 4604, Norway.|Institute of Marine Research, His, 4817, Norway.
authors.forename: Even
authors.initials: E
authors.lastname: Moland
mesh_terms: D000818:Animals; D017753:Ecosystem; D048389:Gadus morhua / Q000502:physiology*; D009664:Norway; D009792:Oceans and Seas; D013696:Temperature
keywords: Norway; VPS; acoustic telemetry; location filtering; marine reserve; resource selection functions; vemco positioning system