Research ArticleAPPLIED ECOLOGY

Global ecosystem overfishing: Clear delineation within real limits to production

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Science Advances  26 Jun 2019:
Vol. 5, no. 6, eaav0474
DOI: 10.1126/sciadv.aav0474
  • Fig. 1 Schematic of stock and EOF.

    (A) Schematic of population overfishing. While a population is experiencing overfishing, the abundance and biomass (here as the number of fish icons) and fish size declines over time, along with many other facets related to population and fleet dynamics. (B) Schematic of EOF. Analogous to population overfishing, EOF is the result of continued fishing pressure on multiple populations, leading to sequential depletion across populations in an ecosystem over time.

  • Fig. 2 The three novel indicators of ecosystem overfishing for major latitudinal bands.

    Values of the potential measures to delineate EOF; the Ryther index (A), the Fogarty ratio index (B), and the Friedland ratio index (C) for all of the five latitudinal bands. The solid black line represents the proposed threshold (for the Friedland ratio; data are below the threshold for Ryther and Fogarty indices and thus is not shown). N Temp, northern temperate zone; S Temp, southern temperate zone.

  • Fig. 3 The three novel indicators of ecosystem overfishing, for example large marine ecosystems in the tropical, temperate, and polar regions.

    Values of the potential measures to delineate EOF; the Ryther index (A to C), the Fogarty ratio index (D to F), and the Friedland ratio index (G to H) for representative examples of the 65 LMEs that had an index above one of the noted threshold values (black lines) at some point during the time series. Not all of the 65 LMEs are shown. The solid black line represents the proposed threshold.

  • Fig. 4 Multiple characterizations of global fishing and fisheries catch demonstrating core criteria of EOF for different regions, with a particular demonstration of polar fishery stasis and increases in tropical fishing.

    (A) Total, global marine capture fisheries catch of all taxa over time. Total marine capture fisheries catch of all taxa over time, as integrated into major latitudinal bands; polar (B), temperate (C), and tropical (D). All latitudinal bands have data from both northern and southern hemispheres. (E) The width at each latitudinal band (four examples given) at which total average annual marine capture fisheries catch exceeded 60 t km−1. (F) Total fishing effort for exemplary latitudinal bands over time. (G) Total CPUE by latitudinal band over time. (H) The proportion of global fish catch in latitudinal bands over time. These are presented in approximate widths as degrees of longitude.

  • Fig. 5 Global patterns in total fisheries catches from over more than 50 years as seen in three example stanzas.

    Total average annual marine capture fisheries catch (including estimates of illegal unreported and discards) of all taxa for 1950–1959 (A), 1970–1979 (B), and 2010–2014 (C).

Supplementary Materials

  • Supplementary Materials

    This PDF file includes:

    • Fig. S1. The classical fishery yield curve showing catch and CPUE compared to effort.
    • Fig. S2. Fishery yield curves for all fish (total) catches for example LMEs.
    • References (56, 57)

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