Observational studies Experimental studies Applied studies

67 participation of women in fishery activities in Nungwi village in Zanzibar Coleman, 1998. Richmond and Mganwa 1994 conducted a study on large pelagics at Matemwe. The study is based on the outcome of the donation of two engine powered sailing dhows by the Netherlands Embassy to two fishing cooperatives in the village. Prior to this the fishermen were using sail-powered outrigger canoes and simple fishing equipment. The most interesting aspect of this study was that, the fishermen themselves conducted the monitoring exercise by completing a daily log book provided by the scientists daily on their catches. The project is still continuing and several reports have been written Richmond and Mganwa, 1994, 1995, Richmond, 1999. Fewer than10 MSc and Phd studies have been conducted. The studies focussed on providing information on specific fishery topics. For example, the biological aspects of Siganids and their mariculture potential in Tanzania Mziray, 1983; the food and feeding habits of Indian mackerel from Zanzibar, Ndawula, 1985; the reproductive biology of the squid in the coastal waters of Zanzibar Mhitu, 1997; the dynamics of the trap fishery in the coastal waters of Zanzibar Mgimwa, 1998; and the population dynamics of the small pelagic fishery in the Zanzibar channel Jiddawi, 1999. In Southern Tanzania several studies have been conducted on fisheries resources in the area by FRONTIER. These studies provide information on fish species diversity in relation to the density and diversity of coral cover as well as providing a description of the main fishery activities in the area Darwall et al., 1995, 1996a, 1996b; Guard, 1999. Frame surveys on fishing units and fishermen have been conducted mainly in Zanzibar by Ngoile 1982, Carrara 1985, Hoekstra et al., 1989 and Lyimo et al. 1997. The surveys establish the status of fishing effort in terms of number and type of gears, number and type of vessels, fishermen on foot and those operating using vessels. The surveys thus establish the geographical concentration of the gears and vessels and also set up baseline information that could be used to compare current fishing effort with the past. This information is very useful in planning and setting up fisheries development and management strategies. Muhando and Ngoile 1995 conducted a study on the nursery potential of mangrove ecosystems in Zanzibar. Amir 1997 and Ongera 1997 have conducted similar studies. In addition to providing a list of fish species found in these areas, they have also conducted length-weight relationships of some of the most common commercial species.

3.3.2 Observational studies

Only 0.9 of the examined literature were of observational nature. These included under water visual surveys in Fumba Peninsula Horrill, et al., 1994. Observational studies also were conducted in seaweed growing sites on the East coast of Zanzibar to observe the distribution and abundance of inshore fish assemblages Svanson and Bergman, 1998. Other studies in Zanzibar included observing fish population structure with special reference to algal farms, Nilsen and Patterson, 1996 and a study of dema traps at Tumbatu. This study examined the placement of these traps on the different habitats and their impact on the environment. This study, however, was only of a short duration but it provided an insight on how the traps are used and what species of fish are caught, where and at which depth Horst, 1999.

3.3.3 Experimental studies

Experimental studies are more related to gear development and usage Losse, 1966, Mahika, 1992, and experiments related to aquaculture such as preferential settlement of oyster spat settlement on different substrates in Zanzibar Jiddawi, 1989, 1997. Another important aquaculture study is the integrated fish-farming model that was developed in Israel and tried at Makoba in Unguja Island by the Institute of Marine Sciences in collaboration with the Prison department. The model includes effluent treatment in order to minimise downstream effects. The study also included local fish feed formulation and trying this feed on fish in the laboratory Mmochi et al., 1996, 1999. Also, an experimental culture of rabbit fish in cages was attempted in the habour area of Zanzibar town Bwathondi, 1981a, 1981b. Experiments however, were very few and comprised only 2.4 of all the studies.

3.3.4 Applied studies

68 Applied studies are related to the experimental studies and these were also very few accounting for 2.7 of all the studies. Mostly they were related to aquaculture experiments such as the cage culture of Siganus spp. Bwathondi, 1981a, the aquaculture of rabbit fish and milkfish in ponds at Makoba Mmochi et al., 1996, 1999 and the experimental culture of oysters, Saccostrea cucccullata, in the habour area of Zanzibar Jiddawi, 1989. Talbot and Newell 1957 attempted the first study on fish aquaculture in marine ponds in Zanzibar. The fish cultured in the experiment was Tilapia, although Chanos chanos later invaded the ponds and became very successful as well. These studies have started to have a positive implication among the people in some areas of Tanzania that have shown great interest of establishing mariculture ponds.

3.3.5 Review studies