By Stephan Moonsammy, BSc, MSc
Published: June 5, 2021 • World Environment Day 2021
For every one kilometre of mangroves lost along the coast and corresponding coastal protection services, it will cost approximately US$10.9 million dollars to build the infrastructure to replace it.
Stephan Moonsammy ✉️, Department of Environmental Studies, Faculty of Earth and Environmental Sciences, University of Guyana
This essay is part of a series by the University of Guyana, Department of Environmental Studies on the United Nations Decade on Ecosystem Restoration 2021-2030. It was first published in the Guyana Chronicle on World Environment Day (June 5, 2021).
The connection between mangrove forests and the well-being of society has been precarious as evident in the literature with several studies showing the importance of mangroves to social well-being (Dev Roy, 2016; Hogarth, 2007; Vo et al., 2012) and others showing a social perception that mangroves are a barren wasteland (Hollis & Thompson, 2007; López-Angarita, 2016) and are being replaced by built infrastructure (Haslett, 2000). In recent years, a lot of traction has been given to the economic importance of mangroves predominantly based on the value of the proliferation of ecosystem services they provide to our society (Vo et al., 2021). The challenge that many researchers have in firmly establishing the value of mangroves to the wider society is that most of society cannot observe the revenue generation capability of mangroves, outside of a few subsistence activities such as fishing or bark harvesting, and few eco-tourism operators (Ostling et al., 2009). When compared to ecosystems such as forests or reefs for instance that can substantiate significant revenue and employment opportunities, mangroves do not have the same appeal.
Mangrove seedlings for regeneration planting. Source: NAREI, 2016.
For this reason, mangroves worth are often undervalued and misrepresented in the economic context of the aggregated value of nature to the economic well-being of a country (Queiroz et al., 2017). The true value of a mangrove is not from the revenue earning capacity, but the significance of the contribution of its regulating ecosystem services to communities. For instance, mangroves regulate hydrological flows from inland to the sea; protect coastlines from storm surges and coastal erosion; slow the intrusion of the sea inland providing a natural sea defense for low-lying countries; provide a habitat for a rich biodiversity of flora and fauna; and function as one of the most productive carbon sequestration systems among all other tree species (Estrada et al., 2014; Ostling et al., 2009). Whenever a stock of mangrove is lost due to pollution or land clearing, society loses the flow of ecosystem services associated with it. The value of the mangroves may then be understood when society has to bear the cost for this loss of these services that the mangroves were providing as a free public good. To give a rough estimate, one kilometre of mangrove reduces a storm surge height by 60% and slows the process of sea-level rise intruding inland. For every one kilometre of mangroves lost along the coast and corresponding coastal protection services, it will cost approximately US$10.9 million dollars to build the infrastructure to replace it (Moonsammy, 2020). According to Costanza et al. (2011), the value of all the ecosystem services provided by one hectare of mangroves annually is worth US$193,845.
Among the key economic considerations when exploring the policy decision for mangroves, is that an estimated value of the ecosystem services should be included into any project decision that will either remove or rehabilitate mangroves. As with any project or policy decision making process, cost benefit analysis capturing the social benefits and costs will yield socially optimal outcomes. The value and contribution of mangrove ecosystems is well documented. As such, rehabilitation efforts can readily justify the need for more project investments as the value of mangrove ecosystem services, which is self-evident, is understood by the wider society.
- Costanza, R., de Groot, R., Sutton, P., van der Ploeg, S., Anderson, S.J., Kubiszewski, I., Farber, S., & Turner K.R. (2011). Changes in the Global Value of Ecosystem Services. Global Environmental Change, 26, pp. 152-158.
- Dev Roy, A.K. (2016). Local community attitudes towards mangrove forest conservation: Lessons from Bangladesh. Marine Policy 74, pp. 186-194. https://doi.org/10.1016/j.marpol.2016.09.021.
- Estrada, G.C.D, Soares, M.L.G., Fernandez, V., & Moura de Almeida, P.M. (2013). The economic evaluation of carbon storage and sequestration as ecosystem services of mangroves: a case study from southeastern Brazil. International Journal of Biodiversity Science, Ecosystem Services & Management 11(1), pp. 29-35. https://doi.org/10.1080/21513732.2014.963676.
- Haslett, S. K. (2000). Coastal systems. London: Routledge.
- Hogarth, P. (2007). The Biology of Mangroves and Seagrasses. OUP: Oxford.
- Hollis, G.E. & Thompson, J.R. (2007). Hydrological Data for Wetland Management. Water and Environment Journal [online]. https://doi.org/10.1111/j.1747-6593.1998.tb00140.x.
- López-Angarita, J., Roberts, C.M., Tilley, A., Hawkins, J.P., & Cooke, R.G. (2016). Mangroves and people: Lessons from a history of use and abuse in four Latin American countries. Forest Ecology and Management 368, pp. 151-162. https://doi.org/10.1016/j.foreco.2016.03.020.
- Moonsammy, S. (2020). Rapid Economic Assessment of Mangrove Ecosystems in Guyana. Technical Report, Landell Mills International, Trowbridge:UK.
- Ostling, J.L., Butler, D.R., & Dixon, R.W. (2009). The Biogeomorphology of Mangroves and Their Role in Natural Hazards Mitigation. Geographic Compass [online], pp. 1607-1624. 10.1111/j.1749-8198.2009.00265.x.
- Queiroz, L.S, Rossi, S, Calvet-Mir, L., Ruiz-Mallén, I., García-Betorz, S., Salvà-Prat, J., & Meireles, A.J. (2017). Neglected ecosystem services: Highlighting the socio-cultural perception of mangroves in decision-making processes. Ecosystem Services 26, pp. 137-145. https://doi.org/10.1016/j.ecoser.2017.06.013.
- Vo, Q.T, Kuenzer, C., Vo, Q.M., Moder, F., & Oppelt, N. (2012). Review of valuation methods for mangrove ecosystem services. Ecological Indicators 23, pp. 431-446. https://doi.org/10.1016/j.ecolind.2012.04.022.
This essay is part of a University of Guyana series in observance of the United Nations Decade on Ecosystem Restoration 2021-2030.