Department of Environmental Management & Toxicology
Permanent URI for this collection
Browse
Browsing Department of Environmental Management & Toxicology by Author "Omoboye, Helen Yetunde"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- ItemAssessment of the Physico-chemical water quality of an Artificial Lake in Osun State, Nigeria, over time and space(International Science Community Association, 2022-04) Omoboye, Helen YetundeThis study investigated the variation in physico-chemical water quality of the Esa-Odo Reservoir over space and timefrom February 2017 to December 2018 at two months interval. To cover the whole reservoir zone, sampling points were chosen horizontally and vertically at marked out stations. Depth, transparency (using Secchi disc) and temperature (using mercuryin-glass bulb thermometer) were determined on field. Other physical and chemical parameters were evaluated using standard methods. The values obtainedrevealed Esa-Odo Reservoir as slightly buffered freshwater with cationic hierarchy of Na >Ca > Mg > K and anion hierarchy of HCO3-> Cl->SO42-. Investigated physical parameters varied the most and were significant for two parameters (True Color and Total suspended solid) spatially. While vertically highly significant variation were observed for four (Temperature, Turbidity, Total suspended solid, apparent and true color) parameters. Seasonally, five of the investigated physical parameters (Turbidity, Total solid, Total suspended solid, apparent and true color) showed very highly significant variation. However, in terms of the chemical parameters investigated, only the salinity parameters showed significant vertical (pH and TDS) and highly significant seasonal (TDS, Alkalinity and Hardness) variations. Moreover, seasonally, the nutrient parameters recorded highly significant variation as well as all ions assessed except potassium. All monitored physico-chemical parameters were within the guide level range as of the World Health Organisation (WHO) for drinking water, therefore Esa odo Reservoir water can be classified as fairly clean, alkaline freshwater. However based on the significant seasonal variations in its water quality, regular proper monitoring of the reservoir is recommended.
- ItemMacro-invertebrates as Indicator of Water Quality of Egbe Reservoir, Egbe-Ekiti, Nigeria(Nature and Science, 2016) Omoboye, Helen YetundeThe study of macro-invertebrate fauna and physico-chemical parameters of Egbe-Reservoir was conducted from May – July, 2009. Physico-chemical parameters of the water samples were determined using standard methods. Sampling of macro-invertebrates was done by Kick sampling method and the macro-invertebrates found were identified under light microscope using low power (10X) and scanning power (40X) magnifications. The Macro-invertebrates obtained from the reservoir composed; Melanoids tuberculata which has 53.3% by number of total macro-invertebrates, Biophalaria pfeifferi 6.7%, Lymnae natalensis 22.5%, Hirudinea 13.3%, oligochaetae with 2.5% and Odonata with 1.7% by number of total macro-invertebrates. The result showed variation in the physico-chemical parameters at different sampling stations in the reservoir. The physico-chemical parameters determined during the period of study fall within optimal limit for productive freshwater. Statistical analysis of the result showed that there were significant correlations (p≤0.05, r=0.555) between Biochemical Oxygen Demand and Dissolved Oxygen. Also, there was an inverse significant correlation (p≤0.05, r=-0.536) between Earthworm and pH. Based on the result recorded during the period of study, Egbe Reservoir was found to be fairly unpolluted and should be subjected to regular monitoring It must however be well treated before consumption. The significant relationship between physico-chemical parameters and macro-invertebrates of the reservoir showed that physicchemical parameters influenced the distribution of macro-invertebrates of the reservoir
- ItemPhysico-chemical analysis and identification of antibiotics resistant Enterobacteriaceae from groundwater sources in Ayobo, Lagos, Nigeria(International Research Journal of Environmental Sciences, 2023-10) Omoboye, Helen YetundeThis study aimed at evaluating the physico-chemical parameters and detection of Enterobacteriaceae of groundwater samples in Ayobo, Lagos State. The physico-chemical and bacteriological parameters were determined using standard methods. Twenty Groundwater samples were selectively collected over a period of 6 weeks from two groundwater stations which were Anchor University and Ayobo community. Groundwater temperature values from both well and borehole ranged from 23.9-27.5°C, with an average value of 24.9°C. Conductivity and TDS had their highest values (99.1μS and 49.3ppm) recorded in well 1 of station 1 while in station 2, the result of the selected physico-chemical water quality parameter revealed that the temperature of groundwater samples ranged from 25.1oC to 26.5oC. pH range from 5.0-7.0 with the highest value (7.0) recorded in sample BOK 1 and BOK 2. Conductivity recorded the highest value of 60.9μS while TDS had the highest value of 63.8ppm. Total mean counts for total viable count, faecal coliforms and total coliforms for Station 1 were as follow: 225.00±7.07CFU/ml, 167.00±4.25CFU/ml and 131per 100ml respectively; and for Station 2: 137.00±1.41CFU/ml, 102.00±1.41CFU/ml and 250 per 100ml respectively, which are all higher than the WHO standard limits. The result of the antibiotics susceptibility profiling revealed that the isolates were resistant to more than three antibiotics. In conclusion, this study showed that borehole water and well water around Ayobo are not safe for direct consumption due to high level of the quality indicator bacteria in them.
- ItemPrimary Productivity of Owalla Reservoir, Osun State, Southwest, Nigeria(New York Science Journal, 2017) Omoboye, Helen YetundeThis study investigated primary productivity of Owalla Reservoir, Osun State, Nigeria. This was with a view to providing relevant information on the primary productivity of the reservoir. Sampling period covered rainy and dry seasons. Seven Sampling stations were selected on the reservoir for this study (designated 1, 2, 2 3, 4, 5, 6 and 7). At Stations 1 and 3, only surface water samples were collected for primary productivity while water samples were collected from three levels of water column (surface, mid-depth and close to the bottom) of the reservoir at other stations (Stations 2, 4, 5, 6, and 7). Primary productivity was determined using Oxygen Method. The data obtained were subjected to appropriate statistical analysis. The gross primary productivity of Owalla Reservoir during the study period ranged from 17.28 to 126.72 KCal/M3/day. The respiration of Owalla Reservoir during the study period ranged from 1.73 to 103.68 KCal/M3/day while the net primary productivity of Owalla Reservoir during the study period was in the range of 4.90 - 45.22 KCal/M3/day. Net productivity accounted for 34.7% of the Gross Productivity. Respiration accounted for 65.3% of the Gross Productivity. The mean value of the net productivity of the reservoir decreased vertically from surface to the bottom. The mean respiration decreased towards the dam site while the vertical variation generally showed decrease vertically from the surface level to the bottom of the reservoir (P≤0.05). Gross primary productivity decreased down the reservoir column from the surface to the bottom and there was very highly significant difference (P≤0.001) in mean value at the three vertical depths. The reservoir can be classified as oligotrophic based on its primary productivity level. However, the lake should be subjected to regular proper monitoring
- ItemProductivity of Owalla Reservoir, Osun State, Southwest, Nigeria(New York Science Journal, 2017) Omoboye, Helen YetundeAbstract: This study investigated primary productivity of Owalla Reservoir, Osun State, Nigeria. This was with a view to providing relevant information on the primary productivity of the reservoir. Sampling period covered rainy and dry seasons. Seven Sampling stations were selected on the reservoir for this study (designated 1, 2, 2 3, 4, 5, 6 and 7). At Stations 1 and 3, only surface water samples were collected for primary productivity while water samples were collected from three levels of water column (surface, mid-depth and close to the bottom) of the reservoir at other stations (Stations 2, 4, 5, 6, and 7). Primary productivity was determined using Oxygen Method. The data obtained were subjected to appropriate statistical analysis. The gross primary productivity of Owalla Reservoir during the study period ranged from 17.28 to 126.72 KCal/M3/day. The respiration of Owalla Reservoir during the study period ranged from 1.73 to 103.68 KCal/M3/day while the net primary productivity of Owalla Reservoir during the study period was in the range of 4.90 - 45.22 KCal/M3/day. Net productivity accounted for 34.7% of the Gross Productivity. Respiration accounted for 65.3% of the Gross Productivity. The mean value of the net productivity of the reservoir decreased vertically from surface to the bottom. The mean respiration decreased towards the dam site while the vertical variation generally showed decrease vertically from the surface level to the bottom of the reservoir (P≤0.05). Gross primary productivity decreased down the reservoir column from the surface to the bottom and there was very highly significant difference (P≤0.001) in mean value at the three vertical depths. The reservoir can be classified as oligotrophic based on its primary productivity level. However, the lake should be subjected to regular proper monitoring.
- ItemWater quality and planktonic community of Owalla Reservoir, Osun State, Southwest Nigeria(Acta Limnologica Brasiliensia, 2022) Omoboye, Helen YetundeAim: Owalla Reservoir, one of the largest and oldest man-made lakes in Osun State supplies potable water to many towns in the state including the state capital, Osogbo. Active fshing activities also takes place in the lake. Inspite of the importance of the reservoir, information on the planktonic community and physico-chemical water quality are scarce. Terefore, this study investigated the water quality and plankton composition of Owalla Reservoir, Osun State, Nigeria, from October 2012 to November 2013 with a view to providing baseline information on limnology of the reservoir. Methods: Seven sampling stations (designated Stations 1-7) were established as representatives of the zones and regions of the reservoir and sampling was conducted quarterly. At Stations 1 and 3, only surface water samples were collected while water samples were collected from the surface, mid-depth and close to the bottom at other stations. Samples for total plankton and physico-chemical water quality were analyzed using standard methods. Results: Te result of the study showed that mean dissolved oxygen (P<0.001), biochemical oxygen demand, conductivity, pH (P<0.001), and alkalinity were higher at the surface of the reservoir. As regards seasonal variation, alkalinity, biochemical oxygen demand had the higher mean values during the rainy season. Also, acidity, dissolved oxygen, and pH showed signifcantly (P<0.001) higher values during the rainy season. One hundred and thirtyseven (137) taxa of phytoplankton and 39 taxa of zooplankton were recorded from the reservoir. Te horizontal pattern of variation showed an increase in the mean abundance of most of phytoplankton groups from inflow to the dam area while vertical variation showed a decrease in mean abundance from surface to the bottom of the reservoir. Most of the phytoplankton and zooplankton taxa were more abundant during the dry season than in the rainy season. Conclusions: Te study concluded that all the monitored physico-chemical water quality parameters were within the guide level range as of the World Health Organisation (WHO) for drinking water, Owalla Reservoir is qualitatively rich in both phytoplankton and zooplankton and the reservoir can support a viable aquatic community and sustainable fshery production
- ItemZooplanktonic Community Assessment over Space and Time: A biomonitoring Tool in an Artificial Lake(Asian Journal of Research in Zoology, 2022) Omoboye, Helen YetundeAims: The prime objective of this study is to determine the taxonomic composition of the zooplankton fauna of Esa-Odo Reservoir in Osun State and determine the spatial (horizontal and vertical) and seasonal variations in the composition, distribution abundance, and community structure of the zooplankton community in the reservoir. Study design: sampling stations were selected horizontally and vertically to cover the entire zones of the reservoir. Planktonic samples were collected at two months intervals for two years. Methodology: Samples were collected from the depth using an improvised Meyer’s water sampler. Net and Total plankton were sampled by filtration and sedimentation methods. Planktonic samples were preserved as 5% formalin and 1% Lugol’s solution. Measurement, enumeration, and scaled pictures of the recorded zooplankton were taken using a photomicrograph. The taxonomic composition of zooplankton biota was determined using identification keys. Data analysis was done using PAST Statistical Package. ANOVA was used to determine the spatio-temporal variations. Results: Fiftyty-three (53) pecies of total zooplankton recorded in this study belong to 4 groups: Rotifera, Cladocera, Copepoda, and Insecta. Rotifera was the most represented group (61.21%). Horizontally, 24 species with the highest mean abundance characterized the lacustrine; while 12 species and 10 species were unique to the transition and riverine zones, respectively. Vertically, most species had their mean abundance decreased from the surface to the bottom of the reservoir. Original Research ArticleOmoboye et al.; AJRIZ, 5(1): 31-47, 2022; Article no.AJRIZ.83773 32 A total of nine (9), two (2) and one (1) species were peculiar to the surface, bottom and mid-depth, respectively. Zooplankton organisms were most abundant during the dry season. Conclusion: Esa-Odo Reservoir comprised highly diversified zooplankton fauna with great potential to support rich aquatic community and fishery production. The reservoir can be classified as fairly clean based on the abundance of the rotifer group. However, the lake should be subjected to regular proper monitoring because of the presence of some pollution tolerant copepod species identified among the zooplankton fauna.