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Climate Capital: Assessing the hidden value of coastal ecosystems

Measuring the fiscal value of ecosystems

Ecosystems provide both direct and indirect services to the environment. Direct services are the ones we can essentially see, and are often given financial value. Many conservationists cite the direct and tangible economic value of the environment in their fight, but this is just one valuation of ecology. Oftentimes, the indirect services, or “hidden” values of the environment are the most significant and compelling reasons for prioritizing conservation. While economic arguments for conservation certainly have merit, the intrinsic functions of an ecosystem are often the most valued. The International Union for Conservation of Nature (IUCN) has called upon the global community to quantify the total value of an ecosystem by combining the values of both the direct and indirect services an ecosystem offers to highlight the importance of protected ecosystems.

Arguably, the most critical service an ecosystem provides is its inherent ability to capture and store carbon. As the world faces pressure to reduce CO2 and mitigate climate change, ascribing economic value to the critical indirect services of the ecosystem is important. Particularly as research has shown that the amount of carbon preserved ecosystems capture pays off in economic gains.

The Kyoto Protocol, a binding agreement set by the United Nations Framework Convention, put the Global Carbon Market into motion, which has lead to evaluations of hidden and indirect ecosystems services. This has created financial incentive for the conservation of valuable ecosystems by putting a price on greenhouse gas emissions and biologically storing units of carbon. However, at the moment it only applies to terrestrial areas. In the past, the science and modeling for marine systems has lagged behind its terrestrial counterpart, but new efforts by scientists to quantify the indirect values of marine ecosystem function have helped the issue gain momentum.

The High Economic Value of Coastal Ecosystems

Coastal ecosystems have proven to be some of the most productive and valuable ecological repositories on the planet. These ecosystems are renowned for their biodiversity as well as their economic value. Fisheries, aquaculture, recreation, and eco-tourism are just some of the ways individuals have made money from the health of coastal ecosystems. Though the health of coastal ecosystems can be profitable, it should come as no surprise that man-made forces are threatening the survival of these ecosystems, inevitably reducing their economic value.

Just one example of the ecosystems threatened by climate change is the iconic king crab fisheries in Alaska. Despite being valued at $100 million USD, ocean acidification threatens the survival of these fisheries. The acidification is the result of increases in atmospheric CO2, which cause ocean pH levels to drop, and decrease the molecules important to calcification. In this environment, shelled creatures, like king crabs, aren’t able to fully develop due to the effects of ocean acidification and thus face increased predation risk and stunted growth. This has an almost immediate impact on the size and quality of crabs caught. If Alaskan crab industry were to crash, people would lose their jobs and the local economy would suffer the consequences. In this scenario, the economic value of this habitat is tangible and direct, and the quoted value of $100 million USD is enough to attract attention.

While the economic value of crab fisheries in Alaska hold fiscal weight, there are many other hidden, or indirect, values of coastal ecosystems. For example, salt marshes help to buffer the impact of storms and flooding, and also filter runoff before it hits the aquatic system. While these benefits are recognized as important, their financial value is difficult to quantify, which creates challenges around building an economic argument for the indirect implications of healthy ecosystems. As a result, many policymakers and resource allocators are less inclined to prioritize sustaining coastal ecosystems that offer intangible benefits.

The increasing value of blue carbon

Indirect services may be hard to quantify, but their importance is starting to attract attention, specifically when it comes to blue carbon. Blue carbon, or the carbon capture by marine ecosystems, differs from the carbon captured by its terrestrial counterpart. In recent years, researchers like Murray and colleagues have started to study the role of blue carbon in combating climate change. Marine systems have high rates of capturing and storing CO2, making them the largest carbon sinks in the world. Coastal marine systems, such as salt marshes, seagrass meadows, coral reefs, and mangroves are active carbon sinks due to their high productivity. In these zones, there are high densities of both microscopic and macroscopic photosynthetic organisms that actively consume CO2 and can effectively store it. In another study, Nellemann and colleagues found that marine ecosystems could capture 55% of all atmospheric CO2. The ability to absorb and store CO2 is a hidden but incredibly valuable aspect of these ecosystems, especially in the face of exponential increases in anthropogenic CO2 as a human-induced factor climate change.

A model for costing marine ecosystems

In a May 2015 PLOS ONE paper, authors Tatiana Zarate-Barrera and Jorge Maldonado were able to adapt and reconfigure a model to help put a fiscal value on indirect value of coastal marine ecosystems specific to their local ecosystems.

Globally, many countries have made efforts to protect their marine ecosystems and resources, often by establishing marine protected areas (MPAs), areas in which biodiversity is protected from further human influence. However, it is often hard to get the funding and support to create more MPAs, and maintain MPAs that are already established. The researchers began to investigate both the carbon-storage ability and potential economic value of that storage within MPAs along the coast of Colombia, with the ultimate goal of providing solid economic evidence for conserving and expanding MPAs.

Total Economic Value (TEV) and its components applied to marine and coastal ecosystems. Figure courtesy of PLOS ONE " Valuing Blue Carbon: Carbon Sequestration Benefits Provided by the Marine Protected Areas in Colombia" (2015).
Total Economic Value (TEV) and its components applied to marine and coastal ecosystems. Figure courtesy of PLOS ONE ” Valuing Blue Carbon: Carbon Sequestration Benefits Provided by the Marine Protected Areas in Colombia” (2015).











The authors adapted a model proposed in a 2012 PLOS ONE paper to fit their local system. Part of the model takes into account the rate of carbon capture by an ecosystem and the dominant biota, the size of the ecosystem, how carbon storage can be divided by sediments and living material, and the depth of the seabed. This part of the model generates an annual amount of carbon uptake by a specific ecosystem based on the size and the biota present. The model then incorporates the price of carbon per unit on the Global Carbon Market to generate a monetary value for the carbon storage for a known amount of coast. Using this model, the researchers were able to estimate that increasing the size and range of MPAs would have a significant and positive economic impact. This new model indicates that the value of these ecosystems is about 16 to 33 million EUR per year, and for the first time puts a concrete monetary value on an indirect service.


Models such as the TEV model pioneered by Pendelton and colleagues are pivotal in global conservation efforts and necessary to help bridge the gap between science and economics. These models can also be adapted to show how much money a country could lose by destroying an ecosystem, conveying a powerful message to policymakers who may otherwise neglect coastal ecosystems.

As climate change tightens its grip, dealing with excess carbon and quelling the global effects are increasingly important. Developing a way to give economic incentive for preserving coastal ecosystems will not only help conservation, but will also help the scientific community address climate change.


Harley, Christopher DG, et al. “The impacts of climate change in coastal marine systems.” Ecology letters 9.2 (2006): 228-241.

IUCN, TNC, World Bank. How Much is an Ecosystem Worth? Assessing the Economic Value of Conservation. Washington, DC; 2004.

Murray BC, Pendleton L, Jenkins WA, Sifleet S. Green Payments for Blue Carbon Economic Incentives for Protecting Threatened Coastal Habitats. Durham, NC: Nicholas Institute for Environmental Policy Solutions; 2011.

Nellemann C, Corcoran E, Duarte C, Valdés L, De Young C, Fonseca L, et al. Blue Carbon. A Rapid Response Assessment. GRID-Arendal: United Nations Environment Programme; 2009.

Pendleton L, Donato DC, Murray BC, Crooks S, Jenkins WA, Sifleet S, et al. Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems. PLOS ONE 2012; 7(9): e43542. doi: 10.1371/journal.pone.0043542 PMID: 22962585

Welch, Craig. “Sea Change: Lucrative crab industry in Danger.” Seattle Times, September 11, 2013.

Zarate-Barrera TG, Maldonado JH (2015) Valuing Blue Carbon: Carbon Sequestration Benefits Provided by the Marine Protected Areas in Colombia. PLoS ONE 10(5): e0126627. doi:10.1371/journal.pone.0126627


Featured image: Le Nguyen throws a line to haul up a crab trap. The Alaskan King Crab industry has been threatened by increasing ocean acidification. Photo courtesy of the Seattle Times, 2013 (Steve Ringman).

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