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and Horrill, 1993. For coastal dwellers, fisheries are very important both as a source of food, supplying 90 of the animal protein they consume, and as a source of income, fishing often being their primary occupation. In
addition, coral reefs are one of the major tourist attractions. Coastal tourism brings foreign currency into the country and provides a livelihood for coastal people.
4.2 Type of datainformation gathered
Out of 189 references on coral reefs in Tanzania, approximately half are baseline studies which assess the condition of reefs. About one-quarter of them are review studies that give information on the importance,
utilisation, threats, degradation, and management of coral reefs or review baseline studies conducted by others. Some papers report observational studies other than baseline, e.g., concerning pollution, coral mining, or
ecotourism. Very few papers are based on experimental or applied studies.
4.2.1 Baseline Studies
Many years ago, a few baseline studies were conducted in Tanzania, which had limited geographical scope. The earliest studies were primarily taxonomic Ortmann, 1892; Werth, 1901; von Marenzeller, 1901; and Crossland
1902;1904, providing information about the presence of coral species in the area. Talbot 1965 described the coral structure and fish fauna of Tutia Reef, off Mafia Island. Hamilton 1975 and Hamilton and Brakel 1984
reported on the structure and coral species composition of four reefs near Kunduchi. i.e., Fungu Yasin which they incorrectly called Fungu Mkadya and the fringing reefs of Mbudya Island, Bongoyo Island and Ras Kankadya as
well as the fringing reefs of Ras Mbegani and the south-east side of Mafia Island.
Thereafter, there was a lull in such studies until recently when extensive baseline studies have been conducted by different groups in several locations. For example Frontier-Tanzania in Mafia Horrill and Ngoile, 1991, 1992;
Darwall and Choiseul, 1995, 1996, the Songo Songo Archipelago Darwall et al., 1994; Choiseul and Darwall, 1996; Darwall, 1996a,b; Darwall and Choiseul, 1996; Darwall et al., 1996a,b,c,d; Darwall et al., 1997; Hanaphy
and Muller, 1997 and Mtwara Guard, 1998; Guard et al., 1998a,b,c. These studies have provided substantial amounts of information on biological and resource use aspects of coral reefs as well as other marine resources.
In Tanga, recent baseline studies have been conducted under the Tanga Coastal Zone Conservation and Development Programme IUCN, 1993; Horrill and Kalombo, 1997a, b; Tanga Coastal Zone Conservation and
Development Programme, 1997.
In the Dar es Salaam area, Kamukuru 1997 conducted a baseline study on the fringing reefs of Bongoyo, Mbudya and Pangavini Islands. Ngowo 1999, Sekadende 1999, Wagner et al. 2000a and Wagner et al.
2000b reported information on habitat type percent cover of hard coral, soft coral, algae, seagrasses, rock, sand, etc., the coral genera present, and the abundance of fish and invertebrates on the landward and seaward sides of
Mbudya Island. In Zanzibar, baseline studies have been reported by Ngoile 1990, Horrill 1992, Horrill et al. 1994, Muhando 1998, Mbjije M.Sc. thesis, in preparation and Kuguru M.Sc. thesis, in preparation.
4.2.2 Other Observational Studies
Observational studies on the condition, health and biological status of coral reefs hard coral cover, live coral versus dead coral, etc., other than baseline studies are rare. A few other types of observation studies have been
conducted. Mohammed et al. 1993 assessed the effects of pollutants on coral reefs around Zanzibar. Johnstone and Suleiman 1998 reported on the interaction between pollution and nutrient dynamics on coral reefs around
Zanzibar. Comparisons were made, with respect to ammonium and phosphate levels, between Chapwani reef, which is in the mainstream of polluted currents from Zanzibar town, and Bawe reef, which is away from the
outflow of pollution. They related differences in these levels to differences in measurements on community metabolism on the two reefs.
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The coral mining industry was studied in Mafia by Dulvy and Darwall 1995 and Dulvy et al. 1996; in Mikindani Bay, Mtwara region, by Solandt and Ball 1999; and in Kigamboni near Dar es Salaam by Jambiya et
al .1996.
The potential for ecotourism in relation to coral reefs as well as other attractions was reported by Andersson 1998 for Zanzibar and by Hansen 1999, Wagner et al. 2000a, and Wagner et al.2000b for Kunduchi and
Mbweni, north of Dar es Salaam.
4.2.3 Experimental Studies
Most of the experimental studies have been related to the recruitment of corals, coral larval settlement and transplantation of corals.
Nzali et al. 1998 and Nzali 1999 studied various factors coral coverlevel of reef degradation, season, water temperature, rainfall, sedimentation, and orientation of surfaces, i.e., upward facing or downward facing affecting
hard coral recruitment on Taa Reef, a nearshore reef near the northern border of Tanzania. Clay tiles were placed on racks 20 cm above the seabed. After retrieving the tiles, they were examined for coral recruits and data were
recorded on the location of recruits on the upper or lower surfaces, their identification, diameter, and their number.
Ohman et al. 1999 determined the effect of coral bleaching on fish populations. This study was partly experimental, in that it began with the transplantation of corals, and partly observational, in that the 1998 coral bleaching event
occurred in the middle of the experiment. Before and after the bleaching event, they recorded data on live coral cover in the transplanted plots, reef structural complexity, fish abundance, and fish species composition.
Experimental studies that are still underway include a study by Muhando Ph.D. thesis, in preparation on techniques to enhance coral larval settlement and to transplant corals as means of promoting coral reef
rehabilitation or restoration in Tanzania. Franklin et al. 1998 experimented on the effect of coral fragment size on the success of culturing such fragments for potential subsequent use in aquaria or for reef rehabilitation.
Kuguru M.Sc., in preparation examines the competitive effect of Rhodactis spp. Cnidaria: Corallimorpharia on hard corals on selected reefs of Zanzibar.
4.2.4 Applied Studies
