What are the major threats to mangroves?

Mangrove deforestation and disturbance of rich organic soils can release more carbon dioxide (CO 2) per hectare than degradation of any other forest type [1]. Over 25% of original mangrove cover has already been lost since the late 19th century.

Mangrove decline occurs primarily due to changes in land and ocean use, as well as reclamation. The conversion of forests to produce commodities is the number one cause of mangrove loss. This is strongly driven by fish and shrimp aquaculture expansion, and rice farming. Expanding oil palm cultivation is also becoming significant [2]. It is estimated that between 2000 and 2016, 80% of global mangrove losses caused by human activities occurred in six Asian countries mainly linked to aquaculture operations to support economic development [3]. Aquaculture expansion is one answer to overfishing, but it has to be sustainably managed to avoid long-term negative effects such as toxic algal blooms and loss of mangroves, their carbon stores, and their services for people. Lastly, coastal erosion, sea level rise, hurricanes, and drought, which are exacerbated by climate change, are leading to die-off and loss of mangrove forests.

Protection and restoration of mangrove trees is a powerful tool, enhancing biodiversity and supporting local communities. You can learn how Only One approaches their projects to protect and revitalize mangroves on their Projects page.

1. Hamilton, S. E. & Casey, D. (2016). Creation of a high spatio-temporal resolution global database of continuous mangrove forest cover for the 21st century (CGMFC-21). Global Ecology and Biogeography, 25(6), 729-738. doi: 10.1111/geb.12449.
2. Spalding, M. D. & Leal, M. (eds.) (2021), The State of the World’s Mangroves 2021. Global Mangrove Alliance. Designed and produced by MSQ Sustain.
3. Goldberg, L., Lagomasino, D., Thomas, N., & Fatoyinbo, T. (2020). Global declines in human-driven mangrove loss. Glob Chang Biol, 26(10), 5844-5855. doi: 10.1111/gcb.15275.

About the author

Vasiliki I. Chalastani is a PhD candidate at the Laboratory of Harbour Works, National Technical University of Athens (NTUA), Greece. Her thesis, “Optimization Approaches for Marine Spatial Planning,” aims to develop tools for optimal use of the marine environment through reconciliation of human activities and conservation features. Previously, following her undergraduate studies as a civil engineer at NTUA, Chalastani pursued her MSc, “Water Air Pollution and Energy at Global and Regional Scales,” at École Polytechnique, Paris, France. While in France, she has completed an internship at the Laboratoire Océanographique de Villefranche and at École Normale Supérieure on ocean-based solutions. From 2018 to 2019, Chalastani acted as a consultant for the Alternate Minister of Maritime Affairs and Insular Policy of Greece, Nektarios Santorinios. In 2018, she worked for the Institute for Sustainable Development and International Relations (IDDRI), Paris, with Alexandre K. Magnan, on the issue of climate change adaptation. In 2019, Chalastani worked for the Saudi Red Sea Project, developing a preliminary marine spatial planning initiative, under the supervision of Carlos M. Duarte. She is a member of the National Chamber of Engineers and the United Nations Sustainable Development Solutions Network (UN SDSN), Greece.