CR2025_49 EMBRACE: Examination of Mangrove Biodiversity, Resilience, and Adaptation for Climate and Ecosystems in The Gambia

Lead Supervisor: Cai Ladd, Department of Geography, Swansea University

Email: C.J.T.Ladd@Swansea.ac.uk

Co-supervisors: Aisling Devine, Department of Biosciences, Swansea University; Graham Clarkson, Department of International Development, University of Reading; Jacqualine Rossette, Department of Geography, Swansea University

Sub-Saharan African countries face severe environmental and climate challenges directly impacting livelihoods and biodiversity. The Gambia, one of the most densely populated and poorest African nations yet has the third highest biodiversity per unit area in the world (Butler 2016). 

The Gambia River dissects the country into two regions, north and south of the river, creating the largest estuary in West Africa and includes extensive mangroves high in biodiversity. These mangrove systems provide critical services such as food security and flooding defence, and they capture more carbon per unit area than terrestrial forests, thereby offering huge potentials for ‘blue carbon’ and ‘biodiversity credit’ economic development. 

However, mangroves in The Gambia have suffered substantial degradation and dieback in recent years (Ceesay et al. 2017), potentially due to disease (Teas & McEwan 1982), illegal logging, poor management, and hydrological changes (Harou et al. 2023). The drivers of mangrove degradation are not fully understood, affecting the success of restoration programs and highlighting gaps in restoration ecology.

Mangrove degradation reduces the country’s climate resilience by increasing flooding risk, depleting carbon sinks, and diminishing protection against increasing sea level rise (Singh et al., 2019). It also threatens livelihoods through declining fish and shellfish stocks and salt intrusion, which degrades agricultural land and threatens food security.

These impacts disproportionately affect rural communities with limited resources to adapt. Yet, no detailed, rigorous socio-ecological or livelihood assessment has been conducted on the impacts of mangrove degradation and dieback. Conservation and restoration of these systems offer opportunities for the country to pursue new financial gains through “blue carbon” and “biodiversity credit” economies, while also enhancing climate resilience and safeguarding local livelihoods. This PhD aims to explore ecosystem-based approaches (EbA) to support mangrove restoration, maintain biodiversity, and help communities adapt to climate change, increasing resilience. The project will be split into three main themes (Fig. 1).

Mangrove Degradation Monitoring and Assessment

Mangrove degradation is not occurring uniformly but occurring in regionally specific areas. Moreover, mangrove restoration planting has been attempted with inconsistent and limited success. This spatial variation offers a chance to identify the main drivers of degradation and clarify the main ecological requirements needed for effective restoration

This theme will address the following question:

1. Can the major drivers of mangrove degradation and dieback be identified, and what key environmental requirements are needed for successful restoration?

This question will be addressed by examining vegetation indices from remote sensing to assess the regional extent of degradation and, in combination with environmental data, identify key drivers. Vegetation surveys will evaluate restoration efforts, identifying areas of successful establishment and seedling failure, and hydrological sensors, including the ’Mini Buoy’ developed at Swansea University (Balke et al., 2021), will monitor intertidal hydrodynamics to prioritize areas for targeted mangrove restoration

Socio-Ecological Consequences of Mangrove Habitat Failure

Mangrove habitat failure causes cascading impacts, including ecosystem collapse, salt intrusion, and contaminated agricultural land, making it unfit for farming. Mangrove degradation also disrupts fishing and oyster harvesting, as these habitats serve as crucial fish nurseries. Additionally, the loss of biodiversity services weakens livelihoods, reduces flood resilience, and undermines climate defences. This project will use participatory qualitative approaches to assess the socio-economic and ecological impacts on local livelihoods (Dayamba et al., 2018), addressing the following question.

1. What are the socio-ecological and economic impacts of mangrove degradation, and which adaptation strategies can improve local livelihoods and enhance climate resilience?

Nature Based Solutions for Mangrove Restoration for Climate Resilience and Poverty Alleviation

Integrating ecological knowledge from quantitative approaches with socio-ecological knowledge from qualitative approaches is essential for developing evidence-based conservation decisions. This integration aims to achieve ecological restoration and poverty alleviation, supporting long-term adaptation under uncertain climate change scenarios. This theme will address the following questions:

1. How can mangrove restoration priorities be established to support ‘blue carbon’ and ‘biodiversity credit’ economies that enhance local livelihoods?

This PhD will collaborate with an NGO partner in The Gambia, the GREAT Institute, focusing on environmental solutions and capacity building through the WACEM project (West Africa Continuous Environmental Monitoring), collecting data to support conservation and climate adaptation (Swansea University 2019).

Training opportunities:

The student will have the opportunity to work with a pre-existing collaboration between Swansea University with The Great Institute, an NGO in The Gambia, gaining firsthand experience in how research informs conservation planning and supports poverty alleviation efforts. Through these partnerships, the student will examine how evidence-based decision making can shape sustainable solutions. They will also be trained in essential skills valuable in academia and beyond, including remote sensing, bio-geomorphology monitoring, field methods, and rapid rural appraisal techniques. This comprehensive training will allow the student to understand and apply these methods to address global environmental challenges. 

Student profile: 

The student should have a background in environmental science, with an interest in international development. Core knowledge in ecosystem function and forest or coastal ecology will be important along with a good understanding of quantitative methods and statistical analyses. Additionally, the student should be open to learning new technical skills, particularly in remote sensing, which will be used for mapping and monitoring ecological changes. Familiarity or willingness to learn participatory approach techniques is also beneficial. A willingness to engage with interdisciplinary methods will be key to the project’s success.