Zoology-Scholarly Publications

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Browsing Zoology-Scholarly Publications by Subject "Aquatic organisms"

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  • Item
    Open Access
    Sublethal concentrations of dichlorvos and paraquat induce genotoxic and histological effects in the Clarias gariepinus
    (The Korean Society of Environmental Health and Toxicology/Korea Society for Environmental Analysis, 2020-08) Oladokun, E.I.
    Non-target aquatic organisms such as fish may be impacted by agricultural activities through the run-off of pesticides from farms into aquatic ecosystems. In this study, the genotoxic (erythrocytic micronuclei) and histological effects of sublethal concentrations (1% and 10% of 96-h median lethal concentration (LC50) values) of two pesticides (dichlorvos and paraquat) were evaluated in Clarias gariepinus (the African Sharptooth Catfish) for 28 days. The 96-h LC50 of dichlorvos and paraquat against fingerlings of C. gariepinus was 730 μg/L and 50 μg/L, respectively. There was a significant dose-dependent increase (p<0.05) in micronuclei in the erythrocytes of exposed C. gariepinus (2.00±0.82 ‰ to 3.25±1.26 ‰ for dichlorvos and 2.25±0.96 ‰ to 4.75±0.96 ‰ for paraquat) compared to control (0.75±0.96 ‰) by day 28. Gill histological alterations such as mild to severe necrosis and blunting of secondary lamellae were observed in C. gariepinus exposed to higher sublethal concentrations of both pesticides. This study showed that non-target aquatic organisms like C. gariepinus may be at risk of adverse biological effects from exposure to pesticides from non-point sources. We recommend environmental monitoring and sensitization on responsible pesticide use to stakeholders. This will forestall potential adverse ecological effects in aquatic ecosystems.
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    Open Access
    Sustain Life Below Water, Save Livelihoods & Human Health: Evidence-Based Recommendations
    (University of Lagos, 2020-12-28) Sogbanmu, Temitope O.
    catch and adverse impacts on fisheries.The current environmental standards for Nigerian coastal waters do not include these priority and emerging pollutants. This has implications for sustainability of aquatic organisms (life below water – UN SDG 14) and ecosystem functioning.There is, therefore, an urgent need to develop contextual environmental guidelines for the priority and emerging p