Blue carbon conservation in West Africa: a first assessment of feasibility

Abstract

The loss of blue carbon ecosystems results in significant levels of carbon emissions and decreased supply of other ecosystem services. West Africa contains approximately 14% of the world's mangrove area but despite 25% of coverage loss between 1980 and 2006, the region's mangroves have not been well studied. This study aims to provide a first step toward increasing the knowledge of the region's blue carbon stocks, with a focus on mangroves, and of their financial value based on their carbon storage benefit alone. The best available data suggest that the region contains 1.97 million hectares of mangroves storing 854 million metric tons of carbon in above-and below-ground biomass and the top meter of soil; 4.8 million hectares of seagrass storing 673 million metric tons of carbon; and 1.2 million hectares of salt marshes storing 303 million metric tons of carbon. Even without including values for other benefits of intact mangroves, the conservation of mangroves in the region appears viable. Specifically, the discounted value of 20-year emission reductions under a conservation scenario is estimated to be between $341.2-569.0 million at an 8% discount rate and carbon prices of $3 and $5 per metric ton respectively.

Integrating blue: How do we make nationally determined contributions work for both blue carbon and local coastal communities?

“…Theme 4: Land rights and tenure What tenure and land rights do we need to ensure local communities have ownership of blue carbon ecosystems? Inadequate or insecure tenure and property rights are recognised as a longstanding barrier to communitybased natural resource management (USAID 2006; Lockie 2013), especially for blue carbon programmes (Hejnowicz et al 2015;Beeston et al 2020;Bryan et al 2020). The allocation of tenure or property rights is often complicated on the coast, where ecosystems are typically common pool resources governed under different and overlapping sectors (Vanderklift et al 2019).…”

“…Experience with REDD ? has shown that changes in carbon rights can lead to land grabbing and the exclusion of traditional landowners (Bryan et al 2020). Hence, processes of formalisation should be founded on principles of deliberation, community partnership and co-production, and should avoid entrenching historical inequalities and setting-up Theme 5: Communication and dissemination How do we scale up local efforts and make it easier for communities to conserve and enhance blue carbon?…”

West African food system resilience

“…It has been suggested that the West African region contains 7.97 million hectares of mangroves, seagrass, and salt marshes, together storing over 1.8 billion tonnes of carbon, mainly located in seven West African countries. Therefore, securing private sector payments for blue carbon could be viable for some West African countries (Bryan et al 2020).…”

Valuation of coastal ecosystem services in the Large Marine Ecosystems of Africa

“…On the other hand, there is a lack of data on seagrass beds (Nordlund et al, 2018). The datasets present on Ocean Data Viewer are more likely to illustrate favorable distribution zones rather than existing contours (Bryan et al, 2020) even in the own view of some of their authors (Jayathilake and Costello, 2018). However, in the absence of suitable alternatives, our estimation of seagrass beds' surface area was based on UNEP's dataset (UNEP-WCMC and Short, 2017) made available through this platform.…”

“…The geographic scale is unprecedented, considering that none of the monetary assessments that have already been conducted in Africa does exceed the regional level (Interwies, 2011;Interwies andGörlitz, 2013 in UNEP andGRID-Arendal, 2016), or individual LME level (Chukwuone et al, 2009). Moreover, they focused on few topics such as fishery resources (Sumaila, 2016), West African marine protected areas (Binet et al, 2012) and carbon sequestration (Bryan et al, 2020). Our approach can be re-used for similar work at other spatial scales (regional, national and local), particularly within the framework of the implementation of the African strategy relating to the blue economy, within which the enhancement of coastal ecosystems is a central concern.…”