Marine Sciences-Scholarly Publications

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Browsing Marine Sciences-Scholarly Publications by Subject "Acute toxicity"

Now showing 1 - 6 of 6
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    Open Access
    Acute Toxicity and Histopathological Effects of Engine Oil on Sarotherodon melanotheron.
    (International Digital Organization for Scientific Information, 2012) Ayoola, S. O.; Alajabo, O.T
    The lethal effects of engine oil effluent on Sarotherodon melanotheron was investigated using pathologic lesions in the gill, kidney and muscle. Five concentrations of 0.035, 0.07, 0.14, 0.21 and0.28 ml/l for 96hrs were used for the experiment. The randomized ANOVA for toxicity of the extract against S. melanotheron showed that there were significant differences in the test. The lethal concentration LC that caused 50% 50 mortality was approximately 1.12mg/l of the engine oil. Lesion observed in the gill epithelium exposed to at the different concentrations of the engine oil were dose dependent with the highest effluent concentration inducing the highest damages which include mild congestion, severe congestion and calcification of the gill. The Kidney tissues of S. melanotheron exposed to the engine oil effluents showed severe congestion, inflammation, cytoplasmic vacuolations which may have been due to glycolysis leading to microsomal and mitochondrial dysfunction. While the muscle tissues were normal even after the exposure. The entire test organism in the control showed inappreciable or no histologic degradation while their staining patterns and cellular arrangement remain unaffected. The result obtained showed that engine oil effluents pose a serious damage to S. melanotheron and was observed that acute concentration of engine oil effluents have histopathological effects on aquatic organisms. It can be deduced that indiscriminate discharge of industrial effluents into water bodies can induce damage to the tissue and organ, which might make the fish vulnerable to diseases and eventually lead to death of prominent edible species of the aquatic environment, Therefore there is need for the adoption of proper effluent treatment technology which would ensure proper treatment of industrial effluent and check the recurrence of oil spillage. Indiscriminate exposure of aquatic organisms to engine oil effluent should be discouraged.
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    Open Access
    Acute toxicity and histopathology of Nile tilapia (Oreochromis niloticus) fingerlings exposed to aqueous and ethanolic extracts of Euphorbia poissonii leaves
    (New Clues in Science, 2011) Ayoola, S. O.
    The lethal effect of aqueous and ethanolic leaf extracts of Euphorbia poissonii on Nile Tilapia, Oreochromis niloticus were investigated. Five concentrations of each extract were tested. The concentrations for aqueous were; 20g/L, 40g/ L, 80g/L, 160g/L and 320g/L. The concentration for the ethanolic were; 0.01g/L,0.1g/L,1.0g/L,10.0g/L and 100g/L. The randomized ANOVA for toxicity of the extracts against Oreochromis niloticus showed that there were significant differences between all treatments (P< 0.05). The 96hours LC50 values of the aqueous and ethanolic leave extracts were 7.13g/L and 0.031g/L respectively. These results showed that the ethanolic extracts were more toxic than the aqueous extracts of Euphorbia poissonii. Histopathological effects were observed in the gill and muscle of Oreochromis niloticus in all concentrations of the aqueous and ethanolic extracts. Effects in the ethanolic extracts include generalized sub mucosal congestion and severe stunting of the secondary lamella in the gills and lesions on the muscles. The effect in the aqueous extracts includes degeneration of gills and necrosis on the muscle. It is also seen that aqueous and ethanolic extracts of Euphorbia poissonii have varying histopathological effects on Oreochromis niloticus fingerlings with increasing effects in higher concentration. The direct use of Euphorbia poissonii should be discouraged in a pond system except as a biological control to disinfect the pond from predators and it is to be used in low concentrations.
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    Open Access
    Acute toxicity of some nigerian crude oils on black jaw tilapia (Sarotherodon melanotheron) Juveniles
    (Fisheries Society of Nigeria, 2018) Omogoriola, H.O; Ayoola, S. O.
    Oil industry activities are sources of major contamination problems in Niger Delta. Pollutants from these activities have significant deleterious effects on aquatic organisms. The study investigated the LC50 values obtained from acute toxicity tests on Sarotherodon melanotheron using Oil- in-Water Dispersion (OWD) of the three selected Nigerian crude oils –Ebok, Meji and Erha. The acute toxicity concentrations of 0, 2, 4, 6 and 8ml/L, 0, 10, 15, 20, and 25ml/L and 0, 25, 37.5, 50 and 62.5ml/L were used to determine the 96h Lethal Concentration (LC50) of Ebok (heavy), Meji (light) and Erha (medium) crude oils respectively. The analysis of variance (ANOVA) showed that there were significant differences (p<0.05) in the quantal response of S. melanotheron to different concentrations of three crude oils at different hours of exposure. These results showed that 96LC50 values for OWD-Ebok, OWD-Meji and OWD-Erha crude oils on S. melanotheron were 0.56ml/L, 6.78ml/L and 24.82ml/L respectively. Based on the acute toxicity tests, Ebok with lower API (>22.30C) gravity was more toxic than other crudes on S. melanotheron. All crude oils were toxic to the fish; their discharge into the water bodies during crudes exploration and exploitation should be discouraged for a safety environment.
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    Open Access
    Acute Toxicity of Water Accommodated Fractions (WAFs) of three Nigerian Crude Oils to Clarias gariepinus (Burchell, 1822)
    (Department of Aquaculture and Fisheries Management, University of Ibadan, 2017) Omogoriola, H.O; Ayoola, S. O.
    Oil industry activities such as exploration, transportation, storage, use and disposal, as well as oil spills are sources of major contamination problems in Niger Delta, which have significant deleterious effects on aquatic organisms. The objective of this study was to report LC values 50 obtained from acute toxicity tests on the African Catfish, C. gariepinus exposed to Water Accommodated Fraction (WAF) –heavy (Ebok), light (Meji) and medium (Erha) crude oils. Acute toxicity concentrations of 0%, 2%, 4%, 6% and 8%, 0%, 15%, 20%, 25% and 30% and c 0%, 40%, 60%, 80% and 100% were used to determine the 96h Lethal Concentration (LC ) of 50 heavy, light and medium crude oils respectively. The analysis of variance (ANOVA) showed that there was a significant (p<0.05) difference in the quantal response of C. gariepinus to different concentrations of the various crude oil types at 24, 48, 72 and 96 hours exposure. These results showed that 96LC values for heavy, light and medium crude oils on C. 50 gariepinus were 0.028 mg TPH/l, 0.177 mg TPH/l and 0.742 mg TPH/l respectively. The 96LC of WAF showed that the heavy crude oil was six times more toxic than light and twenty 50 six times more toxic than medium and on toxicity categorization, the heavy, light and medium crude oils were very highly toxic, highly toxic and highly toxic on C. gariepinus. Based on the acute toxicity tests, heavy with lower API (<22.30C) gravity was more toxic than other crude oils on C. gariepinus. All crude oils are toxic to aquatic organisms especially the fish; their discharge into the water bodies during crude oil exploration, transportation, storage and even sabotage should be discouraged to protect the environment.
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    Open Access
    Comparative study of acute toxicity of three Nigerian crude oils using oil in water dispersion (OWD) method on Clarias gariepinus (African catfish)
    (University of Lagos, 2018) Omogoriola, H.O; Ayoola, S. O.; Otitoloju, A.A
    Oil industry activities such as exploration, transportation, storage, use and disposal, as well as oil spills are sources of major contamination problems in Niger Delta, which have significant deleterious effects on aquatic organisms. The study was to investigate LC50 values obtained from acute toxicity tests on C.gariepinus using Oil in Water Dispersion (OWD) of Ebok,Meji and Erha. The acute toxicity concentrations of Ebok(0, 4, 6, 8 and 10ml/l), Meji (0, 15, 20, 25, and 30 ml/l) andErha (37.5, 50, 62.5 and 75ml/l)were used to determine the 96h Lethal Concentration (LC50) respectively. The analysis of variance (ANOVA) showed that there was a significant difference (p<0.05) in the quantal response of C.gariepinus to different concentrations of Ebok, Meji and Erha crude oils at 24, 48, 72 and 96hours of exposure. These results showed that 96LC50 values for Ebok, Meji and Erha crude oils on C.gariepinus were 6.35 ml/l, 18.35 ml/l and 32.04ml respectively. These showed that Ebok was three times more toxic than Meji and five times more toxic than Erha while Meji crude oil was two times more toxic than Erha on C.gariepinus. Based on the acute toxicity tests, Ebok with lower API gravity is more toxic than other crude oils in C.gariepinus. All crude oils are toxic to aquatic organisms especially the fish; their discharge into the water bodies during crude oil exploration, transportation and storage should be discouraged for a safety environment.
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    Open Access
    Histopathological Effect of Cypermethrin on Juvenile African Catfish (Clarias gariepinus)
    (ISPROMS, 2008-11-15) Ayoola, S. O.; Ajani, E.K
    The acute toxicity of cypermethrin an insecticide, to juvenile African catfish, C. gariepinus was investigated with emphasis on histopathological effects. Clarias gariepinus (Burchell 1822) juvenile were exposed to 0, 1.9, 4.1, 9, 21, and 45mg/l of cypermethrin. The lethal concentration (LC50) value of cypermethrin was 0.063mg/l for 96h of exposure. The mean mortality percentages were 0, 0, 70, 90, 100 and 100, in the order of concentration of 0, 1.9, 4.1, 9, 21 and 45 mg/L respectively. Cypermethin concentration corresponding to the 96h LC50 value for juvenile C. gariepinus was used to study the effects of cypermethin exposures in inducing histopathological changes of gills, liver, kidney and brain. In the gills, filament cell proliferation, cellular infiltration, haemorrhage and epithelial lifting were observed. In the liver, there was vacuolation of hepatocytes and necrosis. In kidney there was exfoliation and swollen with pyknotic nuclei. The brain showed neuronal degeneration and spongiosis. These changes occurred predominantly in the 96h exposure. Respiratory stress, erratic swimming and instant death of fish were observed in exposed fish, which varies with the concentration of the toxicant and it’s showed that mortality increased with increase in concentration. Cypermethrin is highly toxic to juvenile fish.