Differing marine animal biomass shifts under 21st century climate change between Canada’s three oceans
Andrea Bryndum-Buchholz,
Faelan Prentice,
Derek P. Tittensor,
Julia L. Blanchard,
William W.L. Cheung,
Villy Christensen,
Eric D. Galbraith,
Olivier Maury,
Heike K. Lotze
Affiliations
Andrea Bryndum-Buchholz
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
Faelan Prentice
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
Derek P. Tittensor
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
Julia L. Blanchard
Institute for Marine and Antarctic Studies and Center for Marine Socioecology, University of Tasmania, 20 Castray Esplanade, Battery Point TAS 7004, Private Bag 129, Hobart, Tasmania 7001, Australia
William W.L. Cheung
Nippon Foundation-UBC Nereus Program and Changing Ocean Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
Villy Christensen
Institute for the Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
Eric D. Galbraith
Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain Department of Mathematics, Institut de Ciència i Tecnologia Ambientals (ICTA), Universitat Autonoma de Barcelona, 08193 Barcelona, Spain
Olivier Maury
Institut de Recherche pour le Développement (IRD), MARBEC (IRD, University of Montpellier, IFREMER, CNRS), 34203 Sète, France Department of Oceanography, Marine Research Institute, University of Cape Town, 7701 Rondebosch, South Africa
Heike K. Lotze
Department of Biology, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4R2, Canada
Under climate change, species composition and abundances in high-latitude waters are expected to substantially reconfigure with consequences for trophic relationships and ecosystem services. Outcomes are challenging to project at national scales, despite their importance for management decisions. Using an ensemble of six global marine ecosystem models we analyzed marine ecosystem responses to climate change from 1971 to 2099 in Canada’s Exclusive Economic Zone (EEZ) under four standardized emissions scenarios. By 2099, under business-as-usual emissions (RCP8.5) projected marine animal biomass declined by an average of −7.7% (±29.5%) within the Canadian EEZ, dominated by declines in the Pacific (−24% ± 24.5%) and Atlantic (−25.5% ± 9.5%) areas; these were partially compensated by increases in the Canadian Arctic (+26.2% ± 38.4%). Lower emissions scenarios projected successively smaller biomass changes, highlighting the benefits of stronger mitigation targets. Individual model projections were most consistent in the Atlantic and Pacific, but highly variable in the Arctic due to model uncertainties in polar regions. Different trajectories of future marine biomass changes will require regional-specific responses in conservation and management strategies, such as adaptive planning of marine protected areas and species-specific management plans, to enhance resilience and rebuilding of Canada’s marine ecosystems and commercial fish stocks.
