Browsing by Author "Dzoga Mumini"

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    Characterisation of Artisanal Catches in Selected Fishing Areas of The Lower Tana Delta and Malindi-Ungwana Bay, Kenya
    (Western Indian Ocean Journal of Marine Science, 2020-10-29) Dzoga Mumini; Simatele Danny; Munga Cosmas
    Shore-based assessment of fisheries resources in Ngomeni, Kipini and Ozi fishing areas of Malindi-Ungwana Bay and the Lower Tana Delta on the north coast of Kenya was conducted from January to December 2017 to establish catch composition, species richness, and fishing effort (catch-rate, number and types of fishing gears and crafts) in the marine, estuarine and riverine habitats. Distinct catch composition (R = 0.27, P < 0.05) was observed across the three habitats. Catch composition differed significantly spatially and seasonally across the three fishing areas, and between the north east (NE) and south east (SE) monsoon seasons (R = 0.332, P < 0.05). The wolf herring, Chirocentrus dorab, was the most abundant fish species in Ngomeni, centrally located in Malindi-Ungwana Bay, while the catfishes, Arius africanus and Clarias gariepinus, were the most abundant species in Kipini and Ozi, respectively. Gillnets operated from dhows (mashua) and fibre-reinforced plastic (FRP) boats in Ngomeni (marine), and canoes using-basket traps in Ozi (riverine), landed significantly larger Spanish mackerel, Scomberomorus commerson, and sea catfish, Arius africanus (Kruskal Wallis test: Df = 2; F = 197.141; p < 0.001; Df = 2, F = 490, p < 0.001), respectively. Species diversity by area in combination with habitat and type of fishing craft showed higher diversity for Ngomeni in the marine habitat with mashua fishing crafts than in Kipini. Significantly different catch rates (Df = 2, F = 10.43, p<0.001; Df = 1, F = 5.897, p < 0.021) were observed in the three (3) fishing areas and during the NE monsoon and the SE monsoon, respectively. Canoes were the most common fishing craft used, especially in Ngomeni, accounting for 37.1%, and 97.5% in Ozi, while mashua crafts accounted for 44.5% of the total fishing craft in Kipini. Monofilament nets were most common in Ngomeni (34.0%) while basket traps dominated the Ozi site at 63.6%. The Kipini area was dominated by handlines (28.8%). It is therefore evident that the three (3) fishing areas of the Malindi-Ungwana Bay and Lower Tana Delta showed significant differences in catch composition and size of fish caught, attributed partly to the variation in habitat types and fishing methods between the sites. Overall, the Ngomeni area was characterized by more advanced fishing craft with the majority powered by engines, including mashua and FRP boats, compared to Kipini and Ozi fishing areas where canoes were dominant.
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    Publication
    Effect of Selected Environmental factors on Microalgae Diversity and Abundance in Gazi Bay, South Coast Kenya
    (Journal Of Sea Research, 2022-06) Swaleh Miriam; Abubakar Laila; Mwaguni Saeed; Munga Daniel; Okuku Erik; Dzoga Mumini; Fulanda Alexander
    Abstract Microalgal community structure of Gazi Bay, Kenya and association with environmental factors was studied between February, June 2019 and October 2020. Non-Metric Multidimensional Scaling (NMDS) and the Rarefaction curves were used for the analysis of community structure; while Principal Component Analysis (PCA) was used to determine correlation between environmental factors with abundance and species diversity of microalgae. A total of 79 microalgae species belonging to 10 classes were recorded, with diatoms dominating in all the sampling sites. The three most abundant species of microalgae observed were Scripssiela sp, Peridinium quinqeucorne, and Striatella sp. There was temporal and spatial distribution of microalgae in the study area. Microalgae abundance ranged from 942 cells/L to 14,990 cells/L, with the highest mean abundance recorded in February during the dry season. Western creek indicated the highest abundance and species diversity compared to other stations at the bay with a significant difference in sample compositions (R = 0.236, P = 0.002). Pearson correlation coefficient showed that the environmental parameters; Total Dissolved Substances (0.61) and salinity (0.59) had a positive correlation with microalgae abundance. This relationship was significant at p < 0.05 for N = 12. In addition, these parameters had a strong influence on microalgae composition and abundance in the Western creek at Gazi Bay. While the microalgae in Mapononi and Doa were influenced by nitrate levels and pH respectively. Gazi Bay is recognized as an important breeding site for fisheries in the south coast of Kenya. Therefore, our findings may be useful in identifying areas within the bay that may be conserved in order to sustain the coastal community livelihood, and justify effective management of hinterland activities to minimize eutrophication.
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    Publication
    Effect of Selected Environmental Factors on Microalgae Diversity And Abundance In Gazi Bay, South Coast Kenya
    (Journal of Sea Research, 2022-06) Swaleh Mariam; Abubakar Laila; Mwanguni Saeed; Munga Daniel; Okuku Eric; Dzoga Mumini; Fulanda Alexander
    Microalgal community structure of Gazi Bay, Kenya and association with environmental factors was studied between February, June 2019 and October 2020. Non-Metric Multidimensional Scaling (NMDS) and the Rarefaction curves were used for the analysis of community structure; while Principal Component Analysis (PCA) was used to determine correlation between environmental factors with abundance and species diversity of microalgae. A total of 79 microalgae species belonging to 10 classes were recorded, with diatoms dominating in all the sampling sites. The three most abundant species of microalgae observed were Scripssiela sp, Peridinium quinqeucorne, and Striatella sp. There was temporal and spatial distribution of microalgae in the study area. Microalgae abundance ranged from 942 cells/L to 14,990 cells/L, with the highest mean abundance recorded in February during the dry season. Western creek indicated the highest abundance and species diversity compared to other stations at the bay with a significant difference in sample compositions (R = 0.236, P = 0.002). Pearson correlation coefficient showed that the environmental parameters; Total Dissolved Substances (0.61) and salinity (0.59) had a positive correlation with microalgae abundance. This relationship was significant at p < 0.05 for N = 12. In addition, these parameters had a strong influence on microalgae composition and abundance in the Western creek at Gazi Bay. While the microalgae in Mapononi and Doa were influenced by nitrate levels and pH respectively. Gazi Bay is recognized as an important breeding site for fisheries in the south coast of Kenya. Therefore, our findings may be useful in identifying areas within the bay that may be conserved in order to sustain the coastal community livelihood, and justify effective management of hinterland activities to minimize eutrophication.