ZOOPLANKTON

Zooplankton constitute a diverse assemblage in most freshwater habitats. A study on the assessment of physico-chemical Characteristics in relation to zooplankton communities in fresh water habitats in Oghara, Delta State was conducted from January – March 2021. Water and Zooplankton samples were collected at monthly and fortnightly respectively at three different sampling stations. Physicochemical parameter were determined using standard methods while Zooplankton Samples were preserved with 4% formaldehyde solution. Mean temperature ranged from (26.00 ±0.577 - 28.83 ± 1.589). Mean Value of Ph was slightly acidic to neutral, ranging from (6.76 – 6.05). Dissolved Oxygen was quite low typical of most eutrophic water bodies. BOD mean value was relatively high (5.80 – 8.40) owing to
increased organic decomposition by organisms during the study period. Nitrate ranged from (0.57 to 5.27) during the study period. The result of zooplankton composition indicated the presence of 33 species of Zooplanktons belonging to three major classes; Cladocera 1108 individual taxa (93.5%), Rotifera 5 individual taxa (0.43%) and Copepoda 72 individual taxa (6.07%). Cladocera were more diverse with 21 representative species, followed by Copepods and Rotifers with 9 and 3 species respectively

Lentic water bodies in Nigeria are often neglected in favour of flowing systems making them prone to pollution, nutrient enrichment and ecological degradation. This study assessed the zooplankton community structure, physical and chemical characteristics, and water quality of Obazuwa Lake, Edo State, Nigeria.Water and zooplankton samples were collected monthly from May to November, 2024 at three sampling stations. Temperature, pH, and dissolved oxygen (DO) were measured in situ, while other physicochemical parameters were analyzed in the laboratory using standard procedures. Zooplankton specimens were identified using recognized taxonomic keys. Data was analyzed using descriptive statistics, one-way Analysis of variance (ANOVA) to test for spatial variation and Pearson’s correlation to assess relationships between biotic and abiotic components. Water quality index (WQI) was computed to classify lake water quality. Multivariate analysis such as Canonical Correspondence Analysis (CCA), Principal component analysis (PCA) and Redundancy Analysis (RDA) was also used to identify community patterns.