Gravity of human impacts mediates coral reef conservation gains

Joshua E. Cinner*, Eva Maire, Cindy Huchery, M. Aaron MacNeil, Nicholas A. J. Graham, Camilo Mora, Timothy R. McClanahan, Michele L. Barnes, John N. Kittinger, Christina C. Hicks, Stephanie D'Agata, Andrew S. Hoey, Georgina G. Gurney, David A. Feary, Ivor D. Williams, Michel Kulbicki, Laurent Vigliola, Laurent Wantiez, Graham J. Edgar, Rick D. Stuart-Smith & 17 others Stuart A. Sandin, Alison Green, Marah J. Hardt, Maria Beger, Alan M. Friedlander, Shaun K. Wilson, Eran Brokovich, Andrew J. Brooks, Juan J. Cruz-Motta, David J. Booth, Pascale Chabanet, Charlotte Gough, Mark Tupper, Sebastian C. A. Ferse, U. Rashid Sumaila, Shinta Pardede, David Mouillot

*Corresponding author for this work

Research output: Contribution to journalArticle

41 Citations (Scopus)
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Abstract

Coral reefs provide ecosystem goods and services for millions of people in the tropics, but reef conditions are declining worldwide. Effective solutions to the crisis facing coral reefs depend in part on understanding the context under which different types of conservation benefits can be maximized. Our global analysis of nearly 1,800 tropical reefs reveals how the intensity of human impacts in the surrounding seascape, measured as a function of human population size and accessibility to reefs ("gravity"), diminishes the effectiveness of marine reserves at sustaining reef fish biomass and the presence of top predators, even where compliance with reserve rules is high. Critically, fish biomass in high-compliance marine reserves located where human impacts were intensive tended to be less than a quarter that of reserves where human impacts were low. Similarly, the probability of encountering top predators on reefs with high human impacts was close to zero, even in high-compliance marine reserves. However, we find that the relative difference between openly fished sites and reserves (what we refer to as conservation gains) are highest for fish biomass (excluding predators) where human impacts are moderate and for top predators where human impacts are low. Our results illustrate critical ecological trade-offs in meeting key conservation objectives: reserves placed where there are moderate-to-high human impacts can provide substantial conservation gains for fish biomass, yet they are unlikely to support key ecosystem functions like higher-order predation, which is more prevalent in reserve locations with low human impacts.

Original languageEnglish
Pages (from-to)E6116-E6125
Number of pages10
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number27
DOIs
Publication statusPublished - 3 Jul 2018
Externally publishedYes

Keywords

  • marine reserves
  • fisheries
  • coral reefs
  • social-ecological
  • socioeconomic

Cite this

Cinner, J. E., Maire, E., Huchery, C., MacNeil, M. A., Graham, N. A. J., Mora, C., ... Mouillot, D. (2018). Gravity of human impacts mediates coral reef conservation gains. Proceedings of the National Academy of Sciences of the United States of America, 115(27), E6116-E6125. https://doi.org/10.1073/pnas.1708001115