Spatiotemporal Changes in Ghana's Mangrove Ecosystems and Pathways for Restoration Action

The protection and restoration of mangrove ecosystems are recognized as one of the nature-based solutions to a changing climate. They are, however, threatened by anthropogenic and natural stresses. Efforts undertaken in the past years to develop global-scale mangrove extent maps either do not provide up-to-date maps or end up missing mangrove extents at local scales. This study aims to assess the spatiotemporal changes of Ghana's mangrove extent and evaluate the key factors causing these potential changes at the country's regional level. The random forest (RF) classifier was used to develop 2015, 2021 and 2024 mangrove extent maps for Ghana and compared them with each other at the country and regional levels to assess the changes over time. With Kappa coefficients higher than 0.8, the results indicate that Ghana's mangrove extent had declined by 15.4% from 2015 (68.41 km²) to 2024 (57.87 km²), with the country's Western, Central and Greater Accra regions experiencing a decline in their mangrove extents. Only the Volta region experienced an increase in its mangrove extent. These significant mangrove extent changes in Ghana at the three regions, as derived from a comprehensive literature review on Ghana's mangroves, are mainly attributable to urban expansion, indiscriminate waste disposal, wildfires, uncontrolled sand and salt mining, among others. This study highlights the need for countries to have national mangrove extent maps. This will help countries to effectively achieve the Global Mangrove Alliance's goals of halting loss, doubling protection and restoring half of the world's mangroves by 2030.