title: Juvenile Atlantic cod behavior appears robust to near-future CO2 levels.
abstract: BACKGROUND
  Ocean acidification caused by the anthropogenic release of CO2 is considered a major threat to marine ecosystems. One unexpected impact of elevated water CO2 levels is that behavioral alterations may occur in tropical reef fish and certain temperate fish species. These effects appear to alter many different types of sensory and cognitive functions; if widespread and persistent, they have the potential to cause ecosystem changes.
  
  
  METHODS
  We investigated whether economically and ecologically important Atlantic cod also display behavioral abnormalities by exposing 52 juvenile cod to control conditions (500 μatm, duplicate tanks) or an end-of-the-century ocean acidification scenario (1000 μatm, duplicate tanks) for one month, during which time the fish were examined for a range of behaviors that have been reported to be affected by elevated CO2 in other fish. The behaviors were swimming activity, as measured by number of lines crossed per minute, the emergence from shelter, determined by how long it took the fish to exit a shelter after a disturbance, relative lateralization (a measure of behavioral turning side preference), and absolute lateralization (the strength of behavioral symmetry).
  
  
  RESULTS
  We found no effect of CO2 treatment on any of the four behaviors tested: activity (F = 1.61, p = 0.33), emergence from shelter (F = 0.13, p = 0.76), relative lateralization (F = 2.82, p = 0.50), and absolute lateralization (F = 0.80, p = 0.26).
  
  
  CONCLUSIONS
  Our results indicate that the behavior of Atlantic cod could be resilient to the impacts of near-future levels of water CO2.
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, SE-405 30 Göteborg, Sweden ; The Lovén Centre Kristineberg, Kristineberg 566, SE-451 78 Fiskebäckskil, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Jutfelt
authors.affiliation: Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 463, SE-405 30 Göteborg, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Hedgärde
keywords: Behavior; Boldness; Carbon dioxide; Climate change; Gadus morhua; Lateralization; Ocean acidification; Teleost