Spatial-Temporal Patterns of Mangrove Forest Change in Zanzibar: A Case Study of Magharibi ‘B’ and Kati Districts in Unguja, Tanzania

Abstract

Climate change and variability have been affecting marine biodiversity, including the mangroves, which have numerous advantages for the ocean and human life. For instance, the mangrove habitats at Magharibi B and Kati Unguja have been highly impacted by both human and climate factors. As such, the communities living in these areas need a thorough understanding of the importance of this habitat for their coastal life. The study was conducted to determine the spatial-temporal patterns of mangrove forest changes in Zanzibar, where mangrove forests in three villages, namely Kisakasaka, Fuoni Kibondeni, and Kibele, were investigated. The change detection approach using satellite images from different years was employed for analysis, and interviews and questionnaires were used for ground truthing. The study involved 373 household heads who were obtained using purposive and simple random sampling methods. The primary data-gathering approaches were employed. The results revealed that in the year 2000, dramatic changes in mangroves started to be observed. From 1990 to 2020, forest changes were further observed using satellite photos. As for the respondents' responses, the findings show that 73% of respondents believe that mangrove forests are declining. Also, the study revealed that more than 62.5% of all respondents experienced extreme changes in mangroves between 2000 and 2010. In addition, people's perceptions revealed that the mangrove forest was very large before 2000. Apart from the observed forest decline, the study showed that the main causes leading to changes in mangroves were overpopulation, lack of alternate sources of income, poor management, and widespread clearing of mangroves for charcoal, firewood, and construction materials. The study concludes that the community's reliance on the forest is in jeopardy and that the mangrove forest's transformation has had a significant impact on the community's livelihood. Hence, the study recommends revitalizing the forest, regeneration and rehabilitation, and establishing adequate structures. Also, mangrove preservation projects and departments should conduct extensive community mobilization on effective ways to have alternative socio-economic livelihoods as an adaptation mechanism towards relying on mangrove forests.