Investigating changes in fish biodiversity in coastal villages of Zanzibar Island, Tanzania

Abstract

This study was conducted at the coastal villages of Zanzibar Island to investigate changes in fish biodiversity. The methodology mostly involved face-to-face interviews and structured questionnaires. Findings of this research paper revealed that there are twenty seven families of fish species of economically importance in the study area of which Scombridae is the most dominate species. This research study shows that there is no significant difference on the distribution of fish biodiversity in the coastal villages of Kizimkazki vs. Matemwe p>0.86; Matemwe vs. Nungwi p>0.09 and Nungwi vs Kizimkasi p>0.06. Findings of the research study revealed that out of twenty seven families of fish species of economic importance to the household’s income of the fishermen; ten families of those fish species were reported by the highly experienced fishermen to have been depleted over the last four decades. The most devastated fish species perceived by the senior fishermen includes Green hump head parrot fish, Javelin grunter, Rosy dwaft monocle bream, Twinspot red snapper, Green job fish and bicolour. T-test revealed that there is a significant difference on the perception of the fishermen on the changed in fish biodiversity between the three generation. Significant result were found between younger age vs middle age p<0.002; high significant results were found between middle age vs old age p<0.002 and high significant were found between old age vs younger age p<0.000. Findings of the research study revealed that the highly experienced fishermen perceived that the main reasons for the decline of fish biodiversity in the coastal villages of Zanzibar Island were (a) increasing number of fishermen, (b) the uses of destructive fishing gear has devastated marine ecosystem, (c) increasing development of tourism industry have created a new demand for fish market, (d) climate variability and seasonality has contributed negatively on the decline of fish biodiversity. The research study concluded that further decline on fish biodiversity are likely to increase in future unless appropriate enforcement of laws and regulation are established. Key words: Biodiversity, marine fisheries, perception of fishermen changed, fish species.