Chapter 5 Discussion

In this study, methods for mapping fish landing sites and characterize them using spatial analysis in GIS in order to create fish landing sites according to the spatial pattern are shown. Mapping coastal fish landing sites and their characteristics is one approach to sustainable management of the fisheries sector as it helps to visualize the various patterns across large areas. Efforts to describe and map coastal fisheries have been hindered by the obstacles associated lack of resources directed toward data collection, the distant and dispersed nature of the fisheries, limited data availability, and a scarcity of spatial information (Sobo, 2007).

To date, fisheries assessment methods have been largely described using catch metrics and indices of fishing capacity. Catch statistics are far more readily available and do provide information on fishing activities. However, mapping and characterizing fish landing sites will serve as a more accurate basis for understanding the artisanal fisheries and the effects of fishing. In this study, efforts to map and characterize fish landing sites have highlighted the importance of mapping fisheries activity at the landing sites as a first step toward sustainable fisheries managemen. t Geographical locations of fish landing sites (Table 1) were used to represent geographical position of fish landing sites of the earth’s surface and their spatial distribution (Fig. 1) as well as the length of the their coastline (Fig. 2). Mapping of fish landing sites are significant to not only understanding their spatial distribution, but it help us gain a better perspective of various characteristics of those landing sites. For example, one of the main reasons that Custom, Msasani and Kunduchi are the major fish markets is because of their geographic makeup. Almost all these landing sites protected by lagoon, which protect them from wave action and also allow fishers to land their fishing vessels all the time.

Mapping also helped to determines the relationship between landing sites in the study area. Custom, Msasani and Kunduchi are located in town centers with good road network, fish markets with some storage and processing facilities and large numbers of people, which are the factors influencing fishers other landing sites to come and sell their daily catch because of the high fish demand and good fish price at the sites. These factors also affect the amount of fish landed, for example the fish statistics records were available for only three landing sites of Kunduchi, Msasani and Custom (Fig. 10, 11, 12), implying that fishers from other landing sites prefer to sell their daily catch to towns located landing sites. Conversely, Changwahela has different situation. As located far from fishing village in an exposed coastal area not protected, it’s not easily accessible by road all the time, making it not easily accessible by customers and difficult to transport fishing materials to the landing sites. it has been used as fishing camp rather than fish landing site.

Maps of fish landing sites based on recorded descriptions of the spatial extent of a fishery are likely to be a more accurate characterization of fisheries within an area. Furthermore, delineating the fishing effort into broad categories also provides information on the differential impacts among gear types; for example, beach seine gear has been documented to degrade benthic habitat, and gillnets, as highly non-selective gear, typically lead to high mortality of juvenile target and non-target species. There is empirical support for these gear characterizations. The percentage of gillnet was found to be particularly high in Custom suggesting that these landing site has the potential to exhibit high collateral effects in coastal fisheries. Other landing sites had high percentage of selective fishing gears such as handline and longline (Fig. 8), and when dominant fishing gears are mapped (Fig. 9), they provide useful information for characterizing the dominant fishery type at the fishing landing.

By mapping fishing vessel for different fish landing sites, spatially-explicit density of fishing vessels was determined across study area (Fig. 13). It was found that the length of coastline was significantly related to densities fishing vessels, which means fish landing sites with longer coastlines typically had lower densities across the area (Table 3) While the links between density of fishing vessels and coastline length are intuitive and may help provide a coarse characterization of fishing pressure at the landing site, they explained a small proportion of the variability in abundance of fishing vessel and do little to identify which vessel types are dominant at the landing sites.

The percentages of fishing vessels vary among landing sites (Fig. 6), in which some landing sites had high concentration of fishing vessels than others (Fig. 5). Comparison between fish landing sites was based on the similarity index. The index of similarity proposed by Clarke and Warwick (1994) was chosen for this study. This index measured the type and abundance of fishing vessels at the landing sites. The result is illustrated in (Fig. 12), where Kaole and Mbegani were similar landing sites at Bagamoyo district, Msasani and Mbweni were similar at Kinondoni district. Other landing sites were not similar to each other. This comparison is useful as it enable fisheries resource manager to understand the characteristic of the fish landing sites which do exist at a certain coastal area.

To appreciate better how much fishing village population depend on fishing and other fish related activities at fish landing sites, further analysis was carried out to establish the proportion of people relying solely on fisheries for their livelihood. The dependency of artisanal fishery varies from village to village. As illustrated in Figure 17, the percentage of people in fishing village depending on fishing was very low, however, Mlingotini fishing village appeared to depend heavily on fishing. This represents a relatively high percentage of fishermen which would suggest a high vulnerability to any negative change in fish exploitation regime. Although the proportion of fishing village depend on fishing was low in the study area, it is relatively high in Kaole, Pande, Dunda, Mbweni and Ununio. The dependence was found to be lowest in urban fishing village of Msasani and Kunduchi. Thus, the results suggest that the strongest level of dependence on artisanal fisheries in term of subsistence and income is found in the rural fishing village of Bagamoyo District (Table 6). However, it should be noted that most villagers depend on other combination of activities like agriculture, and small business.

Finally, one of the most significant findings of the research was that of the investment value of the fish landing sites, as measured by the value of fishing vessel. The most valued fish landing sites were found to have high higher proportion of expensive vessels whereas low valued landing sites were dominated with few and cheap fishing vessels (Fig. 15). The highest investment value at Kunduchi was striking (Fig. 16), contributed by the high percentage of boats (Fig. 6), which was the most expensive fishing vessel. Although Mlingotini was the second, its investment value was contributed by higher proportion of dhow, second most expensive fishing vessels recorded. Changwahela had the lowest investment value in the study area (Fig. 16), with total investment value of about 25.5 million (Table 5). The low investment value at Changwahela fish landing site was contributed with the dominance of dugout canoe, cheapest fishing vessel recorded in the area. Despite the figures of investment value presented here, it should be noted that value of the landing sites is not determined by fishing vessels only but by other factors that contribute to the total investment value of a particular landing site.