Browsing by Author "Rusekwa, Sadock Pili Boniface"

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    Macroalge Diversity, Levels of Physicochemical Parameters and Anthropogenic Activities at selected sites along the Dar es salaam Coast.
    (University of Dar es salaam, 2019) Rusekwa, Sadock Pili Boniface
    Anthropogenic activities have been reported to cause a change in macroacroalgae diversity. This study aimed at assessing microalgae diversity of microalgae in six sites along Dar es salaam coast; estimating abundance (cover) of selected microalgae species, determining the levels of selected physicochemical parameters as well as documenting human a ctivities in study sites. The study was conducted between June, 2016 and august, 2017. Opportunistic randomly sampling was done within the studied areas during spring low tide. Identification of all collected seaweed samples was done on site and in the laboratory. A total of one hundred and seven (107) species of macroalgae were recorded from all sites. The division Rhodophyta contributed 48%, Chloraphyta (25%), Ochrophyta (25%) and cynophyta(25%).. Common species in all sites were Boergesenia Forbesii, Ulva Fasciata, Ulva Reticulate, Gracilaria Salicornia, Jania Capillacea Cystoceira Myrica and Padina Boryana. Oyster Bay had highest species diversity wheas lowest diversity was recorded at Oceanroad. A total of 225 species (68%) previously collected at these study sites were currently missing. The highest number of missing species was noted at Osyters Bay and the lowest number was recorded at Mjimwema. The difference in species composition and diversity between studied sites is attributed to the nature of substrate, shore topography and human activities conducted at specific site. Increase temperature and destructive human activities are attributed to decrease of macroalgae diversity and altered composition n the study sites. Mean percentage cover was high in August (29.24) ± 5.85%). The mean biomass of. U. faciata was 4.42 ± 0.65 gdw/m2 and 3.90 ± 1.25 gdw/m2 for G. salicornia. The levels of physicochemical parameters recorded at Oyster Bay were as follows: mean temperature (27 ± 0.7oC ), salinity (34.3 ± 0.8‰), Ph( 8.06 ± 0.1), Nitrate (0.091 ± 0.003 mg/l and phosphorus (0.118 ± 0.010 mg/1. In water column and were optimal for macroalgae growth requirements. Nonetheless data obtained from TMA indicates a steady increase in temperature up to 34oC in DSM Region. Human activities such as illegal fishing, trampling, swimming, boating, tourism and harvesting of microalgae for various use, were observed taking place in these study sites. The results suggest that species composition and diversity in study sites is changing and disappearance of some species is a reality.