Responses of ecological indicators to fishing pressure under environmental change: Exploring non-linearity and thresholds


Fu C., Xu Y., Grüss A., Bundy A., Shannon L., Heymans J. J. , ...More

ICES Journal of Marine Science, vol.77, no.4, pp.1516-1531, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 77 Issue: 4
  • Publication Date: 2020
  • Doi Number: 10.1093/icesjms/fsz182
  • Title of Journal : ICES Journal of Marine Science
  • Page Numbers: pp.1516-1531
  • Keywords: ecosystem-based fisheries management, generalized additive model, marine ecosystem model, non-linear response, primary productivity, SOUTHERN BENGUELA, REGIME-SHIFTS, ECOSYSTEM INDICATORS, MARINE ECOSYSTEM, CLIMATE-CHANGE, FISHERIES, SEA, IMPACTS, MODEL, SHELF

Abstract

© International Council for the Exploration of the Sea 2019. All rights reserved.Marine ecosystems are influenced by multiple stressors in both linear and non-linear ways. Using generalized additive models (GAMs) fitted to outputs from a multi-ecosystem, multi-model simulation experiment, we investigated 14 major ecological indicators across ten marine ecosystems about their responses to fishing pressure under: (i) three different fishing strategies (focusing on low-, high-, or all-trophic-level taxa); and (ii) four different scenarios of directional or random primary productivity change, a proxy for environmental change. From this work, we draw four major conclusions: (i) responses of indicators to fishing mortality in shapes, directions, and thresholds depend on the fishing strategies considered; (ii) most of the indicators demonstrate decreasing trends with increasing fishing mortality, with a few exceptions depending on the type of fishing strategy; (iii) most of the indicators respond to fishing mortality in a linear way, particularly for community and biomass-based indicators; and (iv) occurrence of threshold for non-linear-mixed type (i.e. non-linear with inflection points) is not prevalent within the fishing mortality rates explored. The conclusions drawn from the present study provide a knowledge base in indicators’ dynamics under different fishing and primary productivity levels, thereby facilitating the application of ecosystem-based fisheries management worldwide.