Traditionally, siting and sizing decisions for parks and reserves reflected ecological characteristics but typically failed to consider ecological costs created from displaced resource collection, welfare costs on nearby rural people, and enforcement costs.

This paper explores the impact of the re-introduction of access restrictions to forests in Tanzania, through participatory forest management (PFM), that have excluded villagers from forests to which they have traditionally, albeit illegally, had access to collect non-timber forest products (NTFPs). Motivated by our fieldwork, and using a spatial–temporal model, we focus on the paths of forest degradation and regeneration and villagers' utility before and after an access restriction is introduced.

Mafia island and Tanzania fishery ground is rich in variety of vertebrates and fish stock. Because of diversity and variety of these marine resources it is experiencing an increase in fishing effort particularly fishermen, fishing vessel and various fishing gear. This resulted from increase in indigenous and migrant’s fishermen and forces raise complexity in management.