Levels, distribution and fate of pollutants in the coastal waters off Zanzibar town
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Date
2015
Authors
Journal Title
Journal ISSN
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Publisher
University of Dar es Salaam
Abstract
Biofiltration performances of native microorganisms concentrated on East African Doum Palm Fronds (EADPF), Hyphaene compressa (H. Windl. 1878) and Effective Microorganisms (EM) consortium were assessed. Triplicate polyculture tanks (1 m3) with Orechromis urolepis urolepis (Norman, 1922) and Mugil cephalus (Linnaeus, 1758) were used. Seawater treated EADPF (EADPF-F), untreated EADPF (EADPF-U), EM on Polyvinyl Chloride sheets (PVC-EM), EM consortium without media (EM) and Polyvinyl Chloride without EM (PVC) were used except in the control (CONTROL) tanks. PVC-EM, PVC, EADPF-F and EM systems had better ammonia biofiltration efficiency of 83.7 ± 3.13%, 80.9 ± 3.13%, 73.2 ± 5.36% and 66.7 ± 3.23% respectively while EADPF-U had the least (38.4 ± 7.09%). Total suspended solids levels were relatively little in PVC-EM, PVC and EM but high in EADPF-F and EADPF-U systems. Of the two finfish, O. urolepis urolepis had relatively higher specific growth rate (SGR) and survival rate (SR), with EM and EADPF-F systems providing the best SGR (3.41%) and SR (55.6 ± 9.0%) while the CONTROL and EADPF-U provided the least SGR (2.45±0.03%) and SR (27.9 ± 14.7%), respectively. The results showed that EM, PVC-EM and PVC were effective in enhancing both, the effluents biofiltration and growth of O. urolepis urolepis. Higher values in EM and PVC-EM were attributed to both the regenerative characteristics of EM consortium and ability to fix ammonia while excess heterotrophic activities explained the low values in EADPF-U. The EADPF-F, providing the best SR and run-up SGR of 3.17±06 similar to PVC-EM (3.17±04) was revealed as a potential biofilter media and enhancer of periphyton or bioflocs in mariculture system.
Description
Available in print form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF GC1421N92)
Keywords
Marine pollution, Pollutants, Water, Pollution, Coastal waters, ,Zanzibar town
Citation
Nyanda, F. (2015) Levels, distribution and fate of pollutants in the coastal waters off Zanzibar town, Master dissertation, University of Dar es Salaam, Dar es Salaam