Recognizing the importance of ecosystem services (ES) for peoples' livelihoods and well-being is important for decision-making processes on conservation. Mangrove ecosystems in Tanzania are protected by law, but they continue to be exposed to degradation and loss, and there is still limited information about the awareness, preferences, status and trends of the ES they provide. This thesis aims to explore the link between mangrove ecosystem services (MES) and community livelihoods, changes in MES and associated drivers of change, adaptation options and their management in Tanzania, using the Rufiji Delta and Pangani Estuary as case studies. A mixed framework of methods including focus group discussions, key informant interviews, household surveys, direct observations, and literature reviews was used to gather data. Provisioning services were the most commonly identified MES, and they were more often reported to be deteriorating than regulating, cultural, and supporting services. Proximity to mangrove forest and residence time were positively associated with communities' awareness of all identified MES. Poles for building, firewood for cooking, coastal protection, and fisheries habitats were perceived as the most important MES for sustaining local livelihoods, though perceptions varied between sites. Reliance on mangrove resources was significantly predicted by household residence time, household main occupation, household size, and the cost of alternative resources to substitute mangrove wood as a source of domestic fuel. Illegal harvesting of mangrove poles, rice cultivation, climate change and inadequate governance and conservation measures were identified as the most critical drivers of mangrove degradation, but differed significantly from place to place. Fishing was perceived as the most impacted livelihood occupation compared to the other groups of occupations. Potential ways to adapt to environmental changes in the study areas included reliance on MES for ecosystem-based adaptation (EbA), switching of occupation, diversifying crops, offshore fishing, and migrating to other areas. This thesis argues that the linkage between MES and human well-being is site-specific, and drivers impacting on mangroves and their associated services vary spatially and is greatly accelerated by anthropogenic disturbances. Raising more awareness about the multifunctionality of mangroves and committing to participatory forest management that involves local people, as well as reforming the current forest policy by incorporating clear legal mechanisms for engaging communities around mangrove management and diversifying livelihood options are re-emphasized as appropriate ways to improve mangrove conservation. Furthermore, investment by providing adequate funding for conservation in long run rather than relying on short-term international donor-funded projects are recommended to government institutions as a basis for sustainable management of mangrove forests in Tanzania.