Achieving the triple bottom line in the face of inherent trade-offs among social equity, economic return, and conservation
- aNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101;
- bCenter for Marine Assessment and Planning, University of California, Santa Barbara, CA 93106;
- cAustralian Research Council Centre of Excellence for Environmental Decisions, School of Biological Sciences, and
- dGlobal Change Institute, University of Queensland, St. Lucia, QLD 4072, Australia;
- eScience and Knowledge, Conservation International, Arlington, VA 22202;
- fIndonesia Marine Program, The Nature Conservancy, Sanur, Bali 80228, Indonesia;
- gNatural Capital Project, Stanford University, Stanford, CA 94305; and
- hBren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106
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Edited by Richard M. Cowling, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa, and approved January 7, 2013 (received for review October 11, 2012)

Abstract
Triple–bottom-line outcomes from resource management and conservation, where conservation goals and equity in social outcomes are maximized while overall costs are minimized, remain a highly sought-after ideal. However, despite widespread recognition of the importance that equitable distribution of benefits or costs across society can play in conservation success, little formal theory exists for how to explicitly incorporate equity into conservation planning and prioritization. Here, we develop that theory and implement it for three very different case studies in California (United States), Raja Ampat (Indonesia), and the wider Coral Triangle region (Southeast Asia). We show that equity tends to trade off nonlinearly with the potential to achieve conservation objectives, such that similar conservation outcomes can be possible with greater equity, to a point. However, these case studies also produce a range of trade-off typologies between equity and conservation, depending on how one defines and measures social equity, including direct (linear) and no trade-off. Important gaps remain in our understanding, most notably how equity influences probability of conservation success, in turn affecting the actual ability to achieve conservation objectives. Results here provide an important foundation for moving the science and practice of conservation planning—and broader spatial planning in general—toward more consistently achieving efficient, equitable, and effective outcomes.
- marine protected areas
- environmental justice
- marine spatial planning
- ecosystem-based management
- social-ecological systems
Footnotes
- ↵1To whom correspondence may be addressed. E-mail: halpern{at}nceas.ucsb.edu or c.klein{at}uq.edu.au.
Author contributions: B.S.H., C.J.K., C.J.B., M.B., H.S.G., M.R., V.J.T., C.W., and H.P.P. designed research; B.S.H., C.J.K., and C.J.B. performed research; B.S.H., C.J.K., C.J.B., and M.W. analyzed data; and B.S.H., C.J.K., C.J.B., M.B., H.S.G., S.M., M.R., V.J.T., C.W., and H.P.P. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1217689110/-/DCSupplemental.
Freely available online through the PNAS open access option.