Browsing by Author "Mbije, Nsajigwa E"

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Factors and ecological impacts of wildlife habitat destruction in the Serengeti ecosystem in Northern Tanzania
(2006-04) Kideghesho, Jafari R; Nyahongo, Julius W; Hassan, Shombe N; Tarimo, Thadeo C; Mbije, Nsajigwa E
Despite the considerable worldwide efforts to establish the wildlife protected areas - a strategy construed as the most feasible in maintaining the high quality habitats for healthy wildlife populations - destruction of wildlife habitats has remained the leading threat to biodiversity. This destruction, taking different forms (i.e. degradation, fragmentation or outright loss) is a function of the growing human activities - prompted mainly by such factors as poverty, demographic factors, land tenure systems, inadequate conservation status, development policies and economic incentives. This paper reviews these contributing factors and presents the associated ecological impacts – manifested by a decline of wildlife populations and local extinction of species. Provision of adequate conservation status to critical wildlife habitats, addressing the problem of human population growth, adoption of poverty reduction strategies that are conservation- friendly and discouraging the destructive development policies are recommended as the measures to mitigate the problem. Other measures entail genuine involvement of the local communities in conservation, provision of adequate economic incentives, relevant research and participatory land use planning. In conclusion, the paper argues that, given the nature of the problem, if a lasting solution is to be realized, habitat loss should be viewed as a multisectoral rather than a single sectoral issue. Therefore different stakeholders should play an active role in halting and pre-empting the problem. We propose criteria for selection of the relevant stakeholders
Seasonal fluctuations in photochemical efficiency of symbiodinium harbored by three reef-building corals that differ in bleaching susceptibility
(2015) Chauka, Leonard J.; Mbije, Nsajigwa E; Kangwe, Simon J
Coral reefs are amongst the most vulnerable ecosystems to climate change. This study was conducted to evaluate the fluxes in the adaptations of reef-building corals to climate change. In order to explore this, chlorophyll a fluorescence, Symbiodinium abundance and types were monitored in nursery-reared corals for two years in three species that differ in bleaching susceptibility. The species were Pocillopora verrucosa, Porites cylindrica and Acropora formosa. Internal transcribed spacer two (ITS-2) region of nuclear ribosomal DNA genes (rDNA) was used in monitoring the Symbiodinium types associated with the studied coral species. Pulse Amplitude Modulated (PAM) fluorometry was used to determine seasonal changes in chlorophyll a fluorescence. In this study, it was found that A. formosa, P. verrucosa and P. cylindrica maintained their Symbiodinium types; C3u, C1h, and C15 respectively throughout the seasons. A. formosa and P. verrucosa responded significantly to seasonal fluctuation in both solar radiation and sea surface temperature by regulating their Symbiodinium cell density and photochemical efficiency whereas P. cylindrica did not. However, such seasonal fluctuations in these environmental parameters are not accompanied by acquisition of foreign Symbiodinium types from the environmental pool. It is concluded that seasonal fluctuations in both solar radiations and sea surface temperatures are not intense enough to effect acquisition of foreign Symbiodinium types by reef building corals in Zanzibar waters