Projecting future changes in distributions of pelagic fish species of Northeast Pacific shelf seas William W.L. Cheung a,⇑ , Richard D. Brodeur b , Thomas A. Okey c,d , Daniel Pauly e a Nereus Program & Changing Ocean Research Unit, Fisheries Centre, The University of British Columbia, Vancouver V6T 1Z4, Canada b Northwest Fisheries Science Center, NOAA Fisheries, Hatfield Marine Science Center, 2030 Marine Science Drive, Newport, OR 97365, USA c School of Environmental Studies, University of Victoria, Victoria, BC V8W 2Y2, Canada d Ocean Integrity Research, C-70 Pilot Street, Victoria, BC V8V 2A4, Canada e Sea Around Us, Fisheries Centre, University of British Columbia, Vancouver V6T 1Z4, Canada article info Article history: Received 12 November 2013 Received in revised form 30 August 2014 Accepted 8 September 2014 Available online 18 September 2014 abstract Marine life is being affected by changes in ocean conditions resulting from changes in climate and chem- istry triggered by combustion of fossil fuels. Shifting spatial distributions of fish species is a major observed and predicted impact of these oceanographic changes, and such shifts may modify fish commu- nity structure considerably in particular locations and regions. We projected future range shifts of pelagic marine fishes of the Northeast Pacific shelf seas by 2050 relative to the present. We combined published data, expert knowledge, and pelagic fish survey data to predict current species distribution ranges of 28 fish species of the Northeast Pacific shelf seas that occur in the epipelagic zone and are well-represented in pelagic fish surveys. These represent a wide spectrum of sub-tropical to sub-polar species, with a wide range of life history characteristics. Using projected ocean condition changes from three different Earth System Models, we simulated changes in the spatial distribution of each species. We show that Northeast Pacific shelf seas may undergo considerable changes in the structure of its pelagic marine communities by mid-21st century. Ensembles of model projections suggest that the distribution centroids of the stud- ied species are expected to shift poleward at an average rate of 30.1 ± 2.34 (S.E.) km decade 1 under the SRES A2 scenario from 2000 to 2050. The projected species range shifts result in a high rate of range expansion of this group of species into the Gulf of Alaska and the Bering Sea. Rate of range contraction of these species is highest at the Aleutian Islands, and in the California Current Large Marine Ecosystem. We also predict increasing dominance of warmer water species in all regions. The projected changes in species assemblages may have large ecological and socio-economic implications through mismatches of co-evolved species, unexpected trophic effects, and shifts of fishing grounds. These results provide hypotheses of climate change impacts that can be tested using data collected by monitoring programmes in the region. Ó 2014 Elsevier Ltd. All rights reserved. Introduction Anthropogenic climate change is causing changes in ocean con- ditions that are much more rapid than previously known natural change (Brierley and Kingsford, 2009; Hoegh-Guldberg and Bruno, 2010). These include physical (e.g., temperature, ocean cur- rent patterns) and chemical (e.g., acidity, oxygen content) changes (Doney et al., 2012), which have in turn led to biological changes including effects on physiologies, spatial distributions, phenologies (timing), and species assemblages (e.g., Dulvy et al., 2008; Edwards and Richardson, 2004; Hiddink and Ter Hofstede, 2008; Nye et al., 2009; Perry et al., 2005; Pörtner, 2010). Poleward shifts in distributions are one of the most commonly observed changes in marine fishes and invertebrates, given that the physiology, repro- duction, and dispersal of marine species are strongly responsive to temperature and ocean current patterns (Poloczanska et al., 2013). Community-wide distribution shifts were recently observed on the Bering Sea continental shelf where the centres of distribution of 40 taxa of fishes and invertebrates shifted northward by an aver- age of 34 km from 1982 to 2006 (Mueter and Litzow, 2008). A meta-analysis of survey data from around North America shows that temperature change is a significant factor explaining the mag- nitude and direction of shifts in latitude and depth of more than 300 species or species groups (Pinsky et al., 2013). Such changes http://dx.doi.org/10.1016/j.pocean.2014.09.003 0079-6611/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Aquatic Ecosystems Research Laboratory, Fisheries Centre, 2202 Main Mall, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada. Tel.: +1 604 827 3756; fax: +1 604 822 8934. E-mail address: w.cheung@fisheries.ubc.ca (W.W.L. Cheung). Progress in Oceanography 130 (2015) 19–31 Contents lists available at ScienceDirect Progress in Oceanography journal homepage: www.elsevier.com/locate/pocean