## 4 Discussion  
This study aimed to detect and analyze the patterns and dynamics of mangroves in Zanzibar over a 47-year period, i.e., from 1973 to 2020, using a Landsat Earth observation dataset. Since the eighteenth century, mangroves and their products have been extensively exploited [55]. Mangrove wood was a valuable resource that the Sultan of Zanzibar harvested, utilized for construction, and transported to the Middle East, Europe, and America [55; 56]. During that time, mangroves were exploited without any binding management plans in place; therefore, they were severely degraded [55; 56]. This study found that the areal mangrove forest cover has been decreasing over the past 47 years, although the rates of change varied spatially and temporally, in both the Chwaka Bay and Menai Bay. In eastern Chwaka Bay, i.e., the Charawe, Chwaka, and Ukongoroni Villages, mangrove degradation is more severe compared to western Chwaka. The protected Jozani Forest in the southwest of Chwaka Bay may have promoted the conservation of mangrove forests in the area. Since Jozani was designated as a forest reserve in 1952, most of the island's wildlife is found here, as similar habitats elsewhere have been destroyed to make room for human habitation. Chwaka Bay and Jozani Forest were placed under a single management system in 1995 under the name Jozani-Chwaka Bay Conservation Project (JCBCP). In Menai Bay, the areas experiencing the most degradation of mangroves are those closest to villages such as Unguja Ukuu, Pete, and Uzi. Therefore, Menai's mangrove degradation is more prevalent in the western part than in the eastern part. Zanzibar's rate of mangrove degradation is alarming, despite the availability of the current policy and regulatory frameworks to check their degradation. The most affected mangrove species are _C. tagal, R. mucronata_, and _B. gymnorhiza_[57; 58; 59]. Like many other parts of the world, the loss of mangroves in Zanzibar is linked to human activities such as timber/pole cutting, firewood collection, charcoal burning, and crop cultivation [39]. This is due to rapid population growth coupled with poverty and a lack of  
Figure 10: The dynamics of mangrove forests along the coast of Menai Bay in Unguja, Zanzibar from 1973 to 2020.  
alternative livelihoods [20]. The majority of the population in rural Zanzibar are poor, and they rely on firewood for cooking [57; 60]. According to [PERSON] [61] and [PERSON] [62], residents in rural Zanzibar majorly depend on mangroves for their livelihood, resulting in massive mangrove destruction. Coastal communities have been relying on mangroves and their products due to a lack of diversification of livelihood opportunities [62]. According to the National Bureau of Statistics and the Zanzibar Bureau of Statistics, Unguja's population was, c., 250,000 in 1975, doubled to, c., 500,000 in 1996, and reached, c., 800,000 in 2009 [60]. The 2022 census shows that Zanzibar has 1,889,773 residents [63]. With an average population density of 712 people per km\({}^{2}\) and an annual growth rate of 3.1%, the island has one of the densest rural populations in the world. A total of 13.0% of homes cannot afford to eat three meals a day, and around half of the households struggle to meet their basic needs [64]. Therefore, forests in Zanzibar, including mangrove forests, have been cleared for their products and also to create more space for agricultural land, especially in the coastal areas, to meet the rising demand for food and the burgeoning urban centers [58]. The demand for mangrove wood products in Zanzibar was 66,702 m\({}^{3}\) in 1996 and was predicted to rise to about 940,630 m\({}^{3}\) by 2006 [35]. With the current population growth rate, the demand for mangrove was expected to be at, c., 3,240,934 m\({}^{3}\) in 2022. Some mangrove areas have been overexploited to an extent that without human intervention, natural regeneration would not occur and, therefore, they would not regain their ecological functions [59].