An integrative framework for sustainable coral reef restoration

Abstract

Restoration of coral reef ecosystems as a management aid has accelerated globally in response to ever-degrading reef health under climate change. As of 2021, more than US$0.25 billion has been invested into reef restoration activities that are often established without the necessary sustained operational or financial strategies in place to meet their longer-term measurable ecological or social restoration goals. Here we consider that restoration programs must be structured as locally tailored, but globally applicable, social-ecological systems, and hence framed as social-ecological restoration. Such a step is arguably critical for restoration activities to define the economic flows and feedbacks needed for leveraging—and adapting to—diverse finance portfolios that underpin sustained operations. We propose a framework integrating scalability and financing of restoration with the social-ecological system using community-led restoration activity on the Great Barrier Reef. Developing such integrated frameworks must be prioritized to ensure effective reef restoration as global efforts accelerate. Restoration of coral reef ecosystems as a management aid has accelerated globally in response to ever-degrading reef health under climate change. As of 2021, more than US$0.25 billion has been invested into reef restoration activities that are often established without the necessary sustained operational or financial strategies in place to meet their longer-term measurable ecological or social restoration goals. Here we consider that restoration programs must be structured as locally tailored, but globally applicable, social-ecological systems, and hence framed as social-ecological restoration. Such a step is arguably critical for restoration activities to define the economic flows and feedbacks needed for leveraging—and adapting to—diverse finance portfolios that underpin sustained operations. We propose a framework integrating scalability and financing of restoration with the social-ecological system using community-led restoration activity on the Great Barrier Reef. Developing such integrated frameworks must be prioritized to ensure effective reef restoration as global efforts accelerate. Accelerating enthusiasm for ecosystem restoration is fast changing both the research and management landscape for coral reefs globally. Traditional management approaches spanning mitigation of catchment water quality and marine protected areas are proving insufficient to stem reef health declines from climate change and local stressors.1Hughes T.P. Anderson K.D. Connolly S.R. Heron S.F. Kerry J.T. Lough J.M. Baird A.H. Baum J.K. Berumen M.L. Bridge T.C. et al.Spatial and temporal patterns of mass bleaching of corals in the Anthropocene.Science. 2018; 359: 80-83https://doi.org/10.1126/science.aan8048Crossref PubMed Scopus (1151) Google Scholar,2Cramer K.L. Donovan M.K. Jackson J.B.C. Greenstein B.J. Korpanty C.A. Cook G.M. Pandolfi J.M. The transformation of Caribbean coral communities since humans.Ecol. Evol. 2021; 11: 10098-10118https://doi.org/10.1002/ece3.7808Crossref PubMed Scopus (11) Google Scholar Increasingly frequent and severe heat waves over the past three decades have driven repeat mass coral mortality events from “coral bleaching,”1Hughes T.P. Anderson K.D. Connolly S.R. Heron S.F. Kerry J.T. Lough J.M. Baird A.H. Baum J.K. Berumen M.L. Bridge T.C. et al.Spatial and temporal patterns of mass bleaching of corals in the Anthropocene.Science. 2018; 359: 80-83https://doi.org/10.1126/science.aan8048Crossref PubMed Scopus (1151) Google Scholar and 14% global coral cover has been lost between 2009 and 2018 alone.3Souter D. Planes S. Wicquart J. Logan M. Obura D. Staub F. The Sixth Status of Corals of the World.2021https://gcrmn.net/2020-report/Google Scholar Such declines in coral reef health—and hence the associated ecosystem service values (currently estimated globally at US$2.7 trillion3Souter D. Planes S. Wicquart J. Logan M. Obura D. Staub F. The Sixth Status of Corals of the World.2021https://gcrmn.net/2020-report/Google Scholar)—are predicted to continue in the short term even under the most optimistic emissions reduction scenarios,4IPCCMasson-Delmotte V. Zhai P. Pirani A. Connors S.L. Péan C. Berger S. Caud N. Chen Y. Goldfarb L. Gomis M.I. Huang M. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, 2021Google Scholar fueling demand to implement local-scale actions aimed at rebuilding—or “restoring”—ever-degrading reefs.5Kleypas J. Allemand D. Anthony K. Baker A.C. Beck M.W. Hale L.Z. Hilmi N. Hoegh-Guldberg O. Hughes T. Kaufman L. et al.Designing a blueprint for coral reef survival.Biol. Conserv. 2021; 257109107https://doi.org/10.1016/j.biocon.2021.109107Crossref Scopus (43) Google Scholar Indeed, reef restoration initiatives have now accelerated over the past decade to include national-scale research and development programs6National Academies of SciencesEngineering, and medicine.A Research Review of Interventions to Increase the Persistence and Resilience of Coral Reefs. The National Academies Press, Washington, DC2019https://doi.org/10.17226/25279Google Scholar,7Anthony K.R.N. Helmstedt K.J. Bay L.K. Fidelman P. Hussey K.E. Lundgren P. Mead D. McLeod I.M. Mumby P.J. Newlands M. et al.Interventions to help coral reefs under global change—a complex decision challenge.PLoS One. 2020; 15e0236399https://doi.org/10.1371/journal.pone.0236399Crossref Scopus (35) Google Scholar alongside local stakeholder-led community practices.8Boström-Einarsson L. Babcock R.C. Bayraktarov E. 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Lockie S. et al.Coral restoration and adaptation in Australia: the first five years.PLoS One. 2022; 17e0273325https://doi.org/10.1371/journal.pone.0273325Crossref Scopus (2) Google Scholar However, it is unclear how well such initiatives that are typically governed by small-scale, short-term operational capacity11Hein M.Y. Vardi T. Shaver E.C. Pioch S. Boström-Einarsson L. Ahmed M. Grimsditch G. McLeod I.M. Perspectives on the use of coral reef restoration as a strategy to support and improve reef ecosystem services.Front. Mar. Sci. 2021; 8618303https://doi.org/10.3389/fmars.2021.618303Crossref Scopus (23) Google Scholar,12Hein M.Y. Staub F. Mapping the global funding landscape for coral reef restoration.in: International Coral Reef Initiative. 2021: 23www.icriforum.orgGoogle Scholar will ultimately deliver tangible management aids,5Kleypas J. Allemand D. Anthony K. Baker A.C. Beck M.W. Hale L.Z. Hilmi N. Hoegh-Guldberg O. Hughes T. Kaufman L. et al.Designing a blueprint for coral reef survival.Biol. Conserv. 2021; 257109107https://doi.org/10.1016/j.biocon.2021.109107Crossref Scopus (43) Google Scholar given that restoration goals are geared to improve long-term socio-ecological outcomes. Understanding how reef restoration activities can sustain operations to effectively meet their goals thus poses a time-critical challenge as global interest for financing ecosystem restoration grows. In this perspective, we propose that a new paradigm for reef restoration is needed, whereby initiatives must be designed around a framework that integrates three factors central to restoration success: scalability, social connectivity, and economic stability.13McAfee D. Costanza R. Connell S.D. Valuing marine restoration beyond the ‘too small and too expensive.Trends Ecol. Evol. 2021; 36: 968-971https://doi.org/10.1016/j.tree.2021.08.002Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar Reef restoration success to date has largely treated these factors in isolation of one another (e.g., Hein et al.,11Hein M.Y. Vardi T. Shaver E.C. Pioch S. Boström-Einarsson L. Ahmed M. Grimsditch G. McLeod I.M. Perspectives on the use of coral reef restoration as a strategy to support and improve reef ecosystem services.Front. Mar. Sci. 2021; 8618303https://doi.org/10.3389/fmars.2021.618303Crossref Scopus (23) Google Scholar,14Bayraktarov E. Stewart-Sinclair P.J. Brisbane S. Boström-Einarsson L. Saunders M.I. Lovelock C.E. Possingham H.P. Mumby P.J. Wilson K.A. Motivations, success, and cost of coral reef restoration.Restor. Ecol. 2019; 27: 981-991https://doi.org/10.1111/rec.12977Crossref Scopus (64) Google Scholar Bayraktarov et al.11Hein M.Y. Vardi T. Shaver E.C. Pioch S. Boström-Einarsson L. Ahmed M. Grimsditch G. McLeod I.M. Perspectives on the use of coral reef restoration as a strategy to support and improve reef ecosystem services.Front. Mar. Sci. 2021; 8618303https://doi.org/10.3389/fmars.2021.618303Crossref Scopus (23) Google Scholar,14Bayraktarov E. Stewart-Sinclair P.J. Brisbane S. Boström-Einarsson L. Saunders M.I. Lovelock C.E. Possingham H.P. Mumby P.J. Wilson K.A. Motivations, success, and cost of coral reef restoration.Restor. Ecol. 2019; 27: 981-991https://doi.org/10.1111/rec.12977Crossref Scopus (64) Google Scholar) as opposed to interconnected nodes—built around their system-specific social-ecological contexts—where flows and feedbacks can influence operational sustainability. We first examine reef restoration activity and how it has been financed to date, arguing that scale and effectiveness of initiatives has reflected an over-reliance on specific funding mechanisms. We then canvas the diversity of financing mechanisms and tools available for restoration and discuss how they can align to initiatives at different stages of maturity needed for sustained activity. We next consider the need to precisely resolve the local social-ecological system—the complex interconnections between society and ecosystems15Sayles J.S. Mancilla Garcia M. Hamilton M. Alexander S.M. Baggio J.A. Fischer A.P. Ingold K. Meredith G.R. Pittman J. Social–ecological network analysis for sustainability sciences: a systematic review and innovative research agenda for the future.Environ. Res. Lett. 2019; 14: 1-18https://doi.org/10.1088/1748-9326/ab2619Crossref PubMed Scopus (60) Google Scholar,16Felipe-Lucia M.R. Guerrero A.M. Alexander S.M. Ashander J. Baggio J.A. Barnes M.L. Bodin Ö. Bonn A. Fortin M.J. Friedman R.S. et al.Conceptualizing ecosystem services using social–ecological networks.Trends Ecol. Evol. 2022; 37: 211-222https://doi.org/10.1016/j.tree.2021.11.012Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar—within which the restoration initiatives operate. We suggest that a fully developed social-ecological system (SES) is needed to capture reef ecosystem service values and priorities that frame restoration goals and thus the critical tool informing the underlying dynamic investment decision making. We finally present these steps as a propositional integrated framework applied to a case study from the Great Barrier Reef (GBR), which has suffered catastrophic declines in coral cover from recent mass bleaching events.1Hughes T.P. Anderson K.D. Connolly S.R. Heron S.F. Kerry J.T. Lough J.M. Baird A.H. Baum J.K. Berumen M.L. Bridge T.C. et al.Spatial and temporal patterns of mass bleaching of corals in the Anthropocene.Science. 2018; 359: 80-83https://doi.org/10.1126/science.aan8048Crossref PubMed Scopus (1151) Google Scholar Tourism underpins >90% of the GBR’s economic value17Deloitte Access EconomicsAt what Price? the Economic, Social and Icon Value of the Great Barrier Reef.2017https://www2.deloitte.com/content/dam/Deloitte/au/Documents/Economics/deloitte-au-economics-great-barrier-reef-230617.pdfGoogle Scholar and the GBR tourism industry quickly adopted targeted reef restoration to advance stewardship-based management in direct response to catastrophic coral losses in 2016–2017.10McLeod I.M. Hein M.Y. Babcock R. Bay L. Bourne D.G. Cook N. Doropoulos C. Gibbs M. Harrison P. Lockie S. et al.Coral restoration and adaptation in Australia: the first five years.PLoS One. 2022; 17e0273325https://doi.org/10.1371/journal.pone.0273325Crossref Scopus (2) Google Scholar,18Howlett L. Camp E.F. Edmondson J. Edmondson J. Agius T. Hosp R. Coulthard P. Edmondson S. Suggett D.J. Adoption of coral propagation and out-planting via the tourism industry to advance site stewardship on the northern Great Barrier Reef.Ocean Coast Manag. 2022; 225106199https://doi.org/10.1016/j.ocecoaman.2022.106199Crossref Scopus (3) Google Scholar,19Howlett L. Camp E.F. Edmondson J. Hosp R. Taylor B. Coulthard P. Suggett D.J. Active coral propagation outcomes on coral communities at high-value Great Barrier Reef tourism sites.Biol. Conserv. 2023; 279109930https://doi.org/10.1016/j.biocon.2023.109930Crossref Scopus (0) Google Scholar Our case study demonstrates how considering the SES—and hence taking a social-ecological restoration (sensu Kibler et al.20Kibler K.M. Cook G.S. Chambers L.G. Donnelly M. Hawthorne T.L. Rivera F.I. Walters L. Integrating sense of place into ecosystem restoration: a novel approach to achieve synergistic social-ecological impact.Ecol. Soc. 2018; 23: 25https://doi.org/10.5751/ES-10542-230425Crossref Scopus (25) Google Scholar) lens—has been critical to building scale and investment opportunity, and therefore provides a template for other restoration programs. We emphasize that reef restoration is fast becoming implemented into stratified reef management via stakeholder-led activity, so initiatives must urgently develop such integrated, and therefore more sustainable, strategies as restoration financing markets grow.