title: Reconciling fisheries catch and ocean productivity.
abstract: Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM). After removing a small number of lightly fished ecosystems, stark interregional differences in fish catch per unit area can be explained (r= 0.79) with an energy-based model that (i) considers dynamic interregional differences in benthic and pelagic energy pathways connecting phytoplankton and fish, (ii) depresses trophic transfer efficiencies in the tropics and, less critically, (iii) associates elevated trophic transfer efficiencies with benthic-predominant systems. Model catch estimates are generally within a factor of 2 of values spanning two orders of magnitude. Climate change projections show that the same macroecological patterns explaining dramatic regional catch differences in the contemporary ocean amplify catch trends, producing changes that may exceed 50% in some regions by the end of the 21st century under high-emissions scenarios. Models failing to resolve these trophodynamic patterns may significantly underestimate regional fisheries catch trends and hinder adaptation to climate change.
authors.affiliation: Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08540; charles.stock@noaa.gov.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Stock
authors.affiliation: Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08540.
authors.forename: Jasmin G
authors.identifier: 0000-0003-2696-277X
authors.initials: JG
authors.lastname: John
authors.affiliation: School of the Earth, Ocean, and Environment, University of South Carolina, Columbia, SC 29208.|Department of Biological Sciences, University of South Carolina, Columbia, SC 29208.
authors.forename: Ryan R
authors.identifier: 0000-0001-8893-872X
authors.initials: RR
authors.lastname: Rykaczewski
authors.affiliation: Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ 08544-0710.
authors.forename: Rebecca G
authors.initials: RG
authors.lastname: Asch
authors.affiliation: Nippon Foundation-Nereus Program, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
authors.forename: William W L
authors.initials: WW
authors.lastname: Cheung
authors.affiliation: Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ 08540.
authors.forename: John P
authors.initials: JP
authors.lastname: Dunne
authors.affiliation: National Marine Fisheries Service, Narragansett, RI 02882.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Friedland
authors.affiliation: Nippon Foundation-Nereus Program, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
authors.forename: Vicky W Y
authors.initials: VW
authors.lastname: Lam
authors.affiliation: Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ 08544-0710.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Sarmiento
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia.
authors.forename: Reg A
authors.initials: RA
authors.lastname: Watson
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D057231:Climate Change / Q000706:statistics & numerical data; D017753:Ecosystem; D005398:Fisheries / Q000706:statistics & numerical data*; D005399:Fishes / Q000502:physiology; D020387:Food Chain; D008954:Models, Biological; D009792:Oceans and Seas; D010933:Plankton / Q000502:physiology
keywords: climate change; fisheries catch; food webs; ocean productivity; primary production