Saving mangroves, one of the world’s most carbon rich habitats, requires evidence and market driven solutions

We launched the Social Sector Accelerator to seek out, design, and test market-driven and evidence-based solutions to the world’s most pressing social and environmental challenges. We’re excited to announce the launch of our Blue Forests Initiative, an effort to combine advances in behavioral science, innovative finance, and the conservation of one of the world’s most important habitats: mangroves. Here’s why:  

  1. Mangroves sequester carbon at a rate 4 to 5 times higher than tropical upland forests. They store some of this carbon in the vegetation, but most of it is stored in the soils in which they are rooted. Mangrove soil is inundated by tidal water that defines mangrove habitat, but if you reach down and pull out a handful of that soil, you find that it is more like a dense, black paste than like the clay or dirt you might find in your backyard. In healthy mangroves, you can literally feel the carbon in this soil, granular and elemental. Some mangroves in the Dominican Republic store over 1000 tons of carbon per hectare, equivalent to almost 4 tons of CO2.

  2. Mangroves also provide essential habitat for fish. For many species of fish - including those of interest to commercial and artisanal anglers, sport fishers, and scuba divers - mangroves are the “nurseries of the sea.” Mangroves provide protection from predation for young fish until they grow large enough for the journey to a coral reef or the deep sea. Even today, scientists working in mangroves continue to identify new, previously unidentified fish species. Local fishermen of course, are well aware of how important the mangroves are to their livelihood; in places where mangroves are being removed it is common to find conflict between fishermen and those doing the removing.

  3. Mangroves stand in the transitional zone between land and sea like mediators protecting the terrestrial from the aquatic, and vice versa. As rainwater carries sediment or chemical runoff from agriculture or other human activity towards the sea, much of it is filtered out as it passes through the mangroves before it reaches the water, protecting essential marine habitat for coral, fish, and human use. Mangroves could be considered the “kidneys of the coastal landscape” as they remove impurities and make life possible. Ever impartial, mangroves also protect the land and those living in coastal areas from storms. As storms surge, mangroves blunt their blow, limiting flooding and damage in coastal communities. And as sea levels rise, mangroves help to dramatically slow erosion, limiting the amount of land reclaimed by the sea.

So, this is what we know:

  • Mangroves sequester carbon at an astonishingly efficient rate.

  • They are essential for the health of fisheries that much of the world depends on for food.

  • And they help coastal communities to weather violent storms and rising sea levels.

Unfortunately, we also know this:

Around the world, mangroves are being lost at a higher rate than the Amazon and other upland forests. For all the well-placed concern about terrestrial deforestation, mangroves are being lost at a rate of approximately 2% a year while their upland counterparts are lost at much lower rates. As far as carbon impact goes, the deforestation of mangroves results not only in the loss of their sequestration abilities, but also results in the release of the carbon that has been stored in mangroves for perhaps centuries. Furthermore, as is the case with upland forests, the alternate uses of areas previously covered by mangroves such as shrimp and salt ponds and cattle grazing land tend to be sources of greenhouse gases. The net change can be enormous.

Our task then is to develop approaches to mangrove conservation that are replicable and cost-effective. We then need a business model that enables private investment, tapping into the vast sums of capital searching, with limited success, for worthy investments in conservation. And, given that well over half of the world’s mangroves have already been deforested, we must devise a similar approach for their restoration.

Uncovering these approaches requires experimentation. Current efforts have been characterized by a mix of educating landowners and communities about mangrove benefits, government regulation and the establishment of protected areas, and, in the case of restoration, replanting campaigns. Demonstrable impact is hard to come by though, in large part because these interventions rarely consider the motivations behind deforestation or effectively incentivize different behavior, and governments, in most of the countries with mangroves, lack the ability to enforce protections. Because mangrove ecosystems are resilient, their restoration should be relatively simple; unfortunately, replanting campaigns often fail to first reestablish the hydrology mangroves require and thousands of young plants end up dying. Furthermore, because these interventions lack a well-defined methodology, they are difficult to replicate.

As in all our work, our Blue Forests Initiative prioritizes cost-effective, measurably impactful approaches for several reasons:

  1. Evidence-based approaches are easier to scale. Evidence based approaches prioritize isolating the variables of success. By isolating the variables, the approaches tend to be more persuasive to policymakers who need something more than just good intentions to guide where they direct scarce resources. For this reason, we also tend to favor simple interventions where isolating variables is simpler, because we find that they tend to be easier for people in other places to scale.

  2. In a world where climate-change mitigation and adaptation are going to require far more resources than are currently available, we need to make every dollar count. We must implement approaches and activities that get the biggest bang for our buck. Isolating costs and determining the cost-effectiveness of an intervention is often overlooked but essential. For this reason, mangroves are ideal sites in which to work

  3. Sustainable conservation is complicated in a world where immediate human needs are often in tension with the need of future generations for healthy of ecosystems and livable climate. We need to approach our work with humility and curiosity, and in a way that allows us to experiment to learn what works best. This is especially true when we’re talking about interventions that rely on shaping human behavior. If we’re going to encourage landowners and communities to conserve and protect mangroves for both themselves and for future generations we must incentivize alternate behaviors and offset economic losses.

In partnership with the NAMA-Facility and the Government of the Dominican Republic, we are working toward the launch the world’s first Nationally Appropriate Mitigation Action (NAMA) that includes mangrove conservation and restoration at a national scale. To accomplish this, we will apply a decade of research into conservation approaches to assist the Dominican Republic to achieve their sustainability goals in a changing climate. We will accomplish this through conservation and restoration to achieve greenhouse gas emissions reductions while enhancing the sustainability and productivity of coastal communities and ecosystems.

In terms of conserving existing mangroves, we are experimenting with:

  1. Cash payments to landowners or local communities conditioned on their conservation of existing mangroves. As far as we know these payments have never been tested for mangroves before, but a similar approach used to protect upland forests in Uganda proved to be highly cost effective. In Ghana it was found that cutting deforestation rates in half and the resulting costs of delaying the release of that carbon amounted to payments of $0.46 per ton of CO2. Given their simplicity and relatively low cost, cash-based approaches are highly efficient, and are hard to outperform with more complex interventions.

  2. A more traditional, education-based approach. It is important that landowners and coastal communities living near mangroves understand the benefits mangroves provide, the long and short term impacts of their actions on mangroves and what they can do to conserve them. This is why, wherever possible, we work with high schools, universities, and other local actors to teach youth about mangrove ecology and give them hands-on experience with carbon sampling and monitoring.

  3. A combination of cash and education. Our bet is that cash payments can be effective for mangrove conservation because they provide landowners and communities with a tangible incentive to change their behavior and offsets the opportunity costs of mangrove destruction for shrimp farming or grazing land for cattle. However, we think that a simple, easy to replicate education protocol will provide an additional benefit at relatively low cost, while also making the work more sustainable long-term.

New black mangrove growth. Photo: H. O'Donnell

New black mangrove growth. Photo: H. O'Donnell

For its part, mangrove restoration may be more complicated than conservation. Finding a cost-effective solution is nonetheless critical for future generations of coastal residents, so we will be experimenting with a similar strategy of education and incentives for managing restored sites. Again, finding ways to minimize costs to ensure cost-effectiveness will be essential as we refine our approach and develop a financial model to ensure sustainability of impact. As we go, we’ll be working on a framework to help policy makers select the most cost-effective sites for restoration to maximize the return on their investment – whatever its form. 

Experimenting in this way will help us uncover what works and quantify our impact not just in terms of carbon, but for other ecosystem services such as fisheries and storm protection as well. Quantifying impact in this way can help us to monetize the resulting ecosystem services, and develop creative ways to support the scale-up of this work throughout tropical coastal ecosystems over the long-term. This can help countries and even communities participate in the global carbon markets of course, but it may unlock even more creative solutions as well. We will model the economic benefits of increased height, density, and coverage of mangroves as storm buffers for infrastructure such as hotels. This may create an opportunity to insure their conservation and even restoration, similar to what The Nature Conservancy and Swiss Re have done with coral reefs. We expect that demonstrating the impact on fisheries will present similar opportunities.

Our Blue Forests Initiative has started in Dominican Republic but are hungry for opportunities to expand to other places – particularly other Small Island Developing States (SIDS).

The Social Sector Accelerator was formed a bit more than two years ago by its parent organization, Counterpart International. Counterpart has worked with Dominican coastal communities, community based, national and international non-profit organizations, academic and government institutions for nearly 15 years, on everything from sustainable agriculture in the hills to coral gardening in the sea. In building on Counterpart's work, the Accelerator’s mission is to find new business-models to support conservation and sustainable development – business models that are themselves sustainable and do not rely on grants. We’re experimenting with impact bonds, pay for results approaches, and other financial mechanisms. Working at the intersection of science and development we prioritize quantifiable measures of social and environmental impact. If evidence of impact is important to you, we’d like to talk with you as well. We’re always interested in helping others think through their own experimental approaches and learning, and to hear their thoughts on ours.

We hope you’ll get in touch – Hugh O’Donnell, Associate Director: