Marine protected areas (MPAs) are increasingly being used globally to conserve marine resources. However, whether many MPAs are being effectively and equitably managed, and how MPA management influences substantive outcomes remain unknown. We developed a global database of management and fish population data (433 and 218 MPAs, respectively) to assess: MPA management processes; the effects of MPAs on fish populations; and relationships between management processes and ecological effects. Here we report that many MPAs failed to meet thresholds for effective and equitable management processes, with widespread shortfalls in staff and financial resources. Although 71% of MPAs positively influenced fish populations, these conservation impacts were highly variable. Staff and budget capacity were the strongest predictors of conservation impact: MPAs with adequate staff capacity had ecological effects 2.9 times greater than MPAs with inadequate capacity. Thus, continued global expansion of MPAs without adequate investment in human and financial capacity is likely to lead to sub-optimal conservation outcomes.

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This research was supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1052875, as part of the working group: Solving the Mystery of Marine Protected Area (MPA) Performance: Linking Governance, Conservation, Ecosystem Services and Human Well Being. D.A.G. was jointly supported by postdoctoral fellowships from the Luc Hoffmann Institute and SESYNC. We thank the following data providers: Atlantic Gulf Rapid Reef Assessment (AGRRA) contributors and data managers, Conservation International, Healthy Reefs Initiative, I. Williams (NOAA Coral Reef Ecosystem Program), NOAA Coral Reef Conservation Program, K. Knights (Global Database for Protected Area Management Effectiveness), G. Edgar and R. Stuart-Smith (Reef Life Surveys), The Nature Conservancy, Wildlife Conservation Society, and the World Conservation Monitoring Centre. We also thank other members of the SESYNC MPA Pursuit team: A. Agrawal, G. Cid, A. Henshaw, I. Nur Hidayat, W. Liang, P. McConney, M. Nenadovic, J. E. Parks, B. Pomeroy, C. Strasser and M. Webster, and P. Marchand of SESYNC for scientific support. We acknowledge GEF, USAID, and the many other funders who supported authors’ time and data collection. This is contribution no. 9 of the research initiative Solving the Mystery of MPA Performance.

Author information

Author notes

    • David A. Gill

    Present addresses: Moore Center for Science, Conservation International, Arlington, Virginia 22202, USA; George Mason University, Fairfax, Virginia 22030, USA.


  1. National Socio-Environmental Synthesis Center (SESYNC), Annapolis, Maryland 21401, USA

    • David A. Gill
  2. Luc Hoffmann Institute, World Wildlife Fund International, 1196 Gland, Switzerland

    • David A. Gill
  3. Moore Center for Science, Conservation International, Arlington, Virginia 22202, USA

    • Michael B. Mascia
  4. World Wildlife Fund US, Washington DC 20037, USA

    • Gabby N. Ahmadia
    • , Louise Glew
    •  & Helen E. Fox
  5. Department of Geography, Florida State University, Florida 32306, USA

    • Sarah E. Lester
  6. Centre for Biodiversity and Conservation Science, University of Queensland, St Lucia Campus, Brisbane, Queensland 4072, Australia

    • Megan Barnes
  7. Department of Natural Resources and Environmental Management, University of Hawaii, Honolulu HI 96822, USA

    • Megan Barnes
  8. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia

    • Ian Craigie
  9. Wildlife Conservation Society, Bronx, New York 10460, USA

    • Emily S. Darling
  10. Department of Marine & Coastal Sciences, Rutgers University, New Brunswick, New Jersey 08901, USA

    • Christopher M. Free
    •  & Olaf P. Jensen
  11. Conservation Science Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK

    • Jonas Geldmann
  12. Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen E, Denmark

    • Jonas Geldmann
  13. NOAA Coral Reef Conservation Program, Silver Spring, Maryland 20910, USA

    • Susie Holst
  14. Indo-Pacific Division, The Nature Conservancy, Honolulu, Hawaii 96817, USA

    • Alan T. White
  15. Nicholas School of the Environment, Duke University, Beaufort, North Carolina 28516, USA

    • Xavier Basurto
  16. Environmental Change Institute, University of Oxford, South Parks Road, Oxford OX1 3QY, UK

    • Lauren Coad
  17. Centre for International Forestry Research, Bogor (Barat) 16115, Indonesia

    • Lauren Coad
  18. Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Hawaii 96744, USA

    • Ruth D. Gates
  19. The Natural Capital Project, Stanford University, 371 Serra Mall, Stanford, California 94305-5020, USA

    • Greg Guannel
  20. Marine Spatial Ecology Lab, School of Biological Sciences and ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia Campus, Brisbane, Queensland 4072, Australia

    • Peter J. Mumby
  21. UNEP – World Conservation Monitoring Centre, Cambridge CB3 0DL, UK

    • Hannah Thomas
  22. CBER – University College London, London WC1E 6BT, UK

    • Sarah Whitmee
  23. WCPA-SSC Joint Task Force on Biodiversity and Protected Areas, International Union for the Conservation of Nature (IUCN), Quebec J9B 1T3, Canada

    • Stephen Woodley
  24. National Geographic Society, Washington DC 20036, USA

    • Helen E. Fox


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H.E.F. and M.B.M. conceived the study. D.A.G. led the analysis and data compilation with the assistance of H.E.F., M.B.M., G.N.A., L.G., S.E.L., M.B., I.C., E.S.D., C.M.F., J.G., S.H., O.P.J., L.C., G.G., P.J.M, H.T., S.W. and S.W. C.M.F. prepared the maps. D.A.G., H.E.F., M.B.M., G.N.A., L.G. and S.E.L. wrote the manuscript with the input of all the other authors.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to David A. Gill.

Reviewer Information Nature thanks A. Rosenberg, B. Worm and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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    Supplementary Information

    This file contains Supplementary Methods, Supplementary Tables 1-10 and additional references.This file was replaced on 29 March 2017 to add a reference.

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    Supplementary Data 1

    This file contains the MPA management assessment data, a subset of which was used in the analysis.

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    Supplementary Data 2

    This file contains the MPA fish biomass response ratio data, a subset of which was used in the analysis.

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