Marine protected areas: Smart investments in ocean health

The report argues that expanding global networks of no-take marine protected areas (MPAs) is economically advisable, with benefits significantly outweighing costs across all analyzed scenarios. Using a cost-benefit analysis for the period 2015-2050, the study finds that expanding coverage to 30% can generate net benefits between US$490 billion and US$920 billion. The highest returns are associated with 'Protect to Preserve' scenarios that target high-biodiversity areas with low human impact. While MPAs enhance biodiversity, fisheries productivity through spillover, and carbon sequestration in mangroves, the report notes significant data gaps regarding the quantification of various ecosystem services and the specific impacts on high-seas and polar regions.

• Expanding no-take MPAs to 10% and 30% global coverage is economically advisable, with benefit-to-cost ratios ranging from 3.17 to 19.77.
• The net economic benefit of expanding MPAs to 30% coverage is estimated between US$490 billion and US$920 billion for the period 2015-2050.
• The economic rate of return for expanding MPA networks can reach as high as 24%, which is significantly above the 3% discount rate used in the analysis.
• Targeting areas with high biodiversity and low human impact ('Protect to Preserve') yields the highest economic returns, with a benefit-cost ratio of approximately 20:1 for 10% coverage.
• Total costs for achieving 10% MPA coverage are estimated at US$45-47 billion, while 30% coverage costs range from US$223-228 billion (2013 prices, present values).
• MPA expansion exhibits diminishing returns to scale; while absolute net benefits increase from 10% to 30% coverage, the benefit-cost ratio declines because high-value habitats are protected first and fisheries opportunity costs increase disproportionately.
• MPAs can increase fish biomass, density, and species richness, potentially benefiting fisheries through the 'spillover effect' where larvae and adults move beyond protected boundaries.
• Mangrove protection provides significant climate regulation benefits through carbon sequestration and the avoidance of emissions from degradation.
• The number of full-time jobs in MPA management is estimated to range between approximately 156,000 and 183,000 depending on the expansion scenario.
• The report identifies significant data gaps, noting that it likely underestimated benefits by excluding seamounts, seagrass, kelp forests, and non-use 'existence values' of biodiversity.

APA

Reuchlin-Hugenholtz, E., & McKenzie, E. (2015). Marine protected areas: Smart investments in ocean health. WWF International. https://www.worldwildlife.org/documents/731/8u8uxvczvw_Smart_Investments_in_Ocean_Health.pdf

Chicago

Reuchlin-Hugenholtz, Emilie, and Emily McKenzie. Marine protected areas: Smart investments in ocean health. WWF International, 2015. https://www.worldwildlife.org/documents/731/8u8uxvczvw_Smart_Investments_in_Ocean_Health.pdf.

Wikipedia

{{cite report |last1=Reuchlin-Hugenholtz |first1=Emilie |last2=McKenzie |first2=Emily |title=Marine protected areas: Smart investments in ocean health |publisher=WWF International |date=May 2015 |url=https://www.worldwildlife.org/documents/731/8u8uxvczvw_Smart_Investments_in_Ocean_Health.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{reuchlinhugenholtz2015marine, author = {Reuchlin-Hugenholtz, Emilie and McKenzie, Emily}, title = {{Marine protected areas: Smart investments in ocean health}}, institution = {WWF International}, year = {2015}, month = may, url = {https://www.worldwildlife.org/documents/731/8u8uxvczvw_Smart_Investments_in_Ocean_Health.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }