Tanzania National Report - Phase 1: Integrated Problem Analysis

Tanzania has a coastline of 800 km stretching from latitude 4o 49’S at the border with Kenya to the border with Mozambique at latitude 10o 28’S. The continental shelf is narrow with the 200km contour depth about 4 km offshore, except at the Zanzibar and Mafia Channels where the shelf extends for up to 80 km. The islands within the continental shelf include Unguja and Mafia, as well as a number of small islets and reefs. Pemba lies beyond the continental shelf and is therefore oceanic. The area of the shelf to the 200 m depth contour for both mainland and Zanzibar combined is about 30, 000 km. The shelf area is commonly used by the artisanal fishermen and due to the narrowness of the shelf, only a small percentage is trawlable.

Tanzania is renowned for the attractiveness of its coastal and marine environment, high marine biodiversity and rich marine and coastal resources The coastal and marine environment include, among others, major estuaries, mangrove forests, coral reefs, sandy beaches, cliffs, seagrass beds and muddy tidal flats. Sandy-muddy flats or rocky reef platforms are found in the intertidal zone, while the sub-littoral zone consists of extensive seagrass beds and coral reefs. Rivers include Pangani, Wami, Ruvu, Rufiji, Matandu, Mbemkuru, Lukuledi and Ruvuma which all flow to the Indian Ocean, influencing the coastal environment through creation of productive brackish water environments in estuaries, maintenance of deltas, tidal flats and shorelines, as well as nourishment of mangroves and seagrass beds. However, they cause breaks in the chain of coral patch reefs as a result of increased sedimentation.

These coastal ecosystems interact with each other and together sustain a tremendous diversity of marine life and are an important source of sustenance for most coastal communities. For instance, a wide range of important and valued species are found including: an estimated 127 species of coral in 13 families; 8,270 species of invertebrates; 5 species of marine turtles; 1,000 species of fish and breeding and sheltering areas for seabirds.

There are five administrative regions situated along the mainland coast: Tanga, Coast, Dar Es Salaam, Lindi and Mtwara. These regions are further subdivided into several districts. The five coastal regions cover about 15 percent of the country’s total land area and are the home of approximately 25 percent of the country’s population. The populations of these five coastal regions have increased to about eight million, with a growth rate ranging between two and six percent. At this rate, a doubling of the coastal population is expected in as short a period as twelve years.

According to the 1988 census, the estimated population of Tanzania was 23 million and this is projected to have risen to 32 million by the year 2000. Based on a land area of 883,749 km2 , the population density for the country is 36 persons/km2 , while for Dar Es Salaam region, the density is 17,450 persons/km2 . However, in other coastal regions such as Lindi it is less than 12 persons/km2 .

The coastal and marine environments are currently subject to a wide range of natural and anthropogenic disturbances at different intensities and with various combinations. The increasing anthropogenic disturbances are attributed to the growing coastal population, as well as unsustainable use of coastal resources.

This report is structured as follows: Section Two describes the Integrated Problem Analysis methodology used in this study, specifically, highlighting the four phases of the methodology. Priority hot spots, sensitive areas and priority issues are highlighted in Section Three. Section Four presents the results of analysis of environmental and socio-economic impacts of the four priority environmental issues. The results of causal chain analysis of the four priority issues are discussed in detail in Section Five, while Section Six focuses on information gaps, transboundary elements of the environmental causes and the future trends. The Section Seven proposes more specific recommendations to deal with the causes of environmental degradation identified.