Browsing by Author "Gumbo, Jabulani R."

Now showing 1 - 5 of 5

Harmful algae in aquaculture systems in Ngerengere Catchment, Morogoro, Tanzania: Descriptive community structure and environmental concerns
(Elsevier Ltd, 2021-12) Offoro N. Kimambo, Offoro N.; Gumbo, Jabulani R.; Msagati, Titus A.M.; Chikoore, Hector
Climate variability, anthropogenic activities, and hydrological shifts are fueling the nuisance of harmful algal blooms in water bodies. Unfortunately, cyanobacterial harmful algal blooms (CyanoHABs) dynamics have not received much attention in Tanzania. The study aimed to identify and characterize common species of cyano bacteria and examine their possible change in composition and succession in the Ngerengere catchment, Morogoro, Tanzania. Water samples from the selected reservoirs were collected quarterly between October 2017 and September 2018 for physico-chemical parameters in situ and in the laboratory. A benchtop FlowCAM was used for the identification of cyanobacteria and compared with the literature and available online databases. Principal component analysis (PCA) was used to examine the association between the physico-chemical variables and meteorological patterns. The study found common CyanoHABs such as Microcystis, Cylindrospermopsis, Anabaena (Dolichospermum), Lyngbya as well as other species such as diatoms and Euglena which are also considered nuisance. Virtually, a colonial cyanobacteria species dominated the fishponds, while Mindu Dam was more of filamentous species. The study suggest that Mindu dam, based on Carlson’s Trophic State Index (TSI), falls under eutrophic while the fishponds were hypereutrophic. Associated physico-chemical conditions, heavy rainfall and prolonged dry conditions influenced cyanobacteria bloom dynamics. The hydrological connectivity between the fishponds and the Mindu Dam poses a threat to public health because a significant population in Morogoro depends on Mindu Dam for domestic water supply. There is a need for the development of a frame work for mitigative and adaptive measures in the catchment, especially during pre-and post-occurrence of blooms.
Harmful algae in aquaculture systems in Ngerengere Catchment, Morogoro, Tanzania: Descriptive community structure and environmental concerns
(Elsevier Ltd, 2022) Kimambo, Offoro N.; Gumbo, Jabulani R.; Msagati, Titus A.M.; Chikoore, Hector
Climate variability, anthropogenic activities, and hydrological shifts are fueling the nuisance of harmful algal blooms in water bodies. Unfortunately, cyanobacterial harmful algal blooms (CyanoHABs) dynamics have not received much attention in Tanzania. The study aimed to identify and characterize common species of cyano bacteria and examine their possible change in composition and succession in the Ngerengere catchment, Morogoro, Tanzania. Water samples from the selected reservoirs were collected quarterly between October 2017 and September 2018 for physico-chemical parameters in situ and in the laboratory. A benchtop FlowCAM was used for the identification of cyanobacteria and compared with the literature and available online databases. Principal component analysis (PCA) was used to examine the association between the physico-chemical variables and meteorological patterns. The study found common CyanoHABs such as Microcystis, Cylindrospermopsis, Anabaena (Dolichospermum), Lyngbya as well as other species such as diatoms and Euglena which are also considered nuisance. Virtually, a colonial cyanobacteria species dominated the fishponds, while Mindu Dam was more of filamentous species. The study suggest that Mindu dam, based on Carlson’s Trophic State Index (TSI), falls under eutrophic while the fishponds were hypereutrophic. Associated physico-chemical conditions, heavy rainfall and prolonged dry conditions influenced cyanobacteria bloom dynamics. The hydrological connectivity between the fishponds and the Mindu Dam poses a threat to public health because a significant population in Morogoro depends on Mindu Dam for domestic water supply. There is a need for the development of a frame work for mitigative and adaptive measures in the catchment, especially during pre-and post-occurrence of blooms.
The occurrence of cyanobacteria blooms in freshwater ecosystems and their link with hydro-meteorological and environmental variations in Tanzania
(Elsevier Ltd, 2019-03) Kimambo, Offoro N.; Gumbo, Jabulani R.; Chikoore, Hector
Cyanobacteria (blue-green algae) are photosynthetic bacteria that under favorable environmental conditions produce secondary metabolites (cyanotoxins) which are harmful to the environment, including humans. The mass proliferation of harmful cyanobacteria is termed CyanoHABs. CyanoHABs can adapt to different climatic fluctuations, therefore, understanding their dynamics in freshwater systems is crucial. Variation in climatic and hydrological processes, changing land use and economic growth all influence the occurrence and distribution of CyanoHABs. There have been inadequate CyanoHAB studies at local scales, therefore their occurrence and dynamics cannot be generalized. This study reviews and synthesizes cases of CysnoHAB occurrence, magnitude, and timing and how these are linked with climatic and hydrological variations in the United Republic of Tanzania. In this study, a scoping review approach was adopted. Research articles, reports, and databases were consulted. The most common species of toxin-producing cyanobacteria were identified in different water bodies in Tanzania, as well as the record of mass fatality of birds (Lesser Flamingo) in Lake Manyara, which in almost all cases occurred during dry years. While previous studies on CyanoHAB dynamics and their links to climate, hydrological, and environmental changes have not been undertaken in Tanzania, there are studies in Lake Victoria and Tanganyika. Therefore, there should be an immediate response from water users, managers, researchers, and water authorities to address and actively engage in monitoring and managing the risks associated with CyanoHABs in Tanzania.
Retrospective analysis of Chlorophyll-a and its correlation with climate and hydrological variations in Mindu Dam, Morogoro, Tanzania
(Elsevier Ltd, 2014-11-06) Kimambo, Offoro N.; Chikoore, Hector; Gumbo, Jabulani R.; Msagati, Titus A. M.
The measurement of Chlorophyll-a in aquatic systems has usually correlated to harmful algae in water bodies. Harmful algal blooms (HABs) are as a result of massive proliferation of blue-green algae (Cyanobacteria). Harmful algal blooms (HABs) pose threats to both the environment as well as human health, and despite this well-known fact, their monitoring and management are still challenging. Climate change, extreme weather events, and hy- drological changes are the main drivers and predicted to benefits HABs dynamics in most parts of the world. In Tanzania, studies of HABs proliferation and their possible correlation with variability in climate and hydrology still lag behind despite high demand for developing predicting tools and prevention of HABs proliferation. The present study reports on the retrospective analysis of HABs variation in Mindu Dam located in Morogoro, Tanzania using remote sensing techniques. In the present study comparison between in situ measurement and ocean color (OC2) Chlorophyll-a with the surface reflectance's (band and band combinations) of Landsat 7 and Landsat 8 Operational Land Imager (OLI), was performed. Another approach involved searching for patterns and trends, and teleconnection between Chlorophyll-a index (best band ration) and the climate and hydrological variations in the catchment. The findings demonstrated that minimum and maximum temperatures, solar radi- ation, Chlorophyll-a concentration registered significant increasing trends. Wind speed and directions, water levels for Mindu Dam showed a significant decreasing trend. On the other hand, rainfall showed no trend. The patterns suggest that there are link and causality between the HABs variations and meteorological parameters such as temperatures, solar radiations, and water levels. The study, therefore, contributes to the application of recent advances in remote sensing and retrospectively analysis of bloom dynamics and search for their link with climate and hydrological changes.
The unusual reddish-bloom appearance in a freshwater fishpond at Kingolwira National Fish Farming Center, Morogoro, Tanzania
(IJE, 2020-05) Kimambo, Offoro N.; Gumbo, Jabulani R.; Msagati, Titus A.M; Chikoore, Hector
The study aimed to examines a case of what constituted the uncommonly reddish-bloom appearance in the fishponds during the dry season (September 2018) at Kingolwira National Fish Farming Center located in Morogoro, Tanzania. The study used a benchtop FlowCAM® to investigate species' morphology. One-time assessment of physico-chemical characteristics during the event was performed from the reddish and non- reddish fishponds. Images were compared with the available literature, but also t-test statistics were performed to examine the difference between the fishponds. The results show that the fishponds were significantly (p<0.05) different from each other in terms of physico-chemical parameters except for water temperatures. Furthermore, Microcystis species dominated the non-reddish fishpond whereas Euglenophytes species were pervasive in the reddish fishpond. The two species have the potential to produce secondary metabolites (toxins) or to produce a hypoxia condition that is harmful to the fishery, aquatic ecology, and human. To confirm toxicity nature and dynamics further, future studies should consider extensive and regular diurnal and long-term monitoring.