Title: Evaluation of Pollution Status of Okamini Stream, Port Harcourt Using Palmer Algal Pollution Index and Water Variables
Authors: Anyiamuka
O.K.
Otene
B.B.
Dube
R.L.
Volume: 10
Issue: 6
Pages: 158-167
Publication Date: 2026/06/28
Abstract:
Pollution status of Okamini Stream, Port Harcourt using Palmer algal pollution index and water variables was studied between July and September, 2025. Surface water and plankton samples were collected monthly and analyzed with SPSS 26.0 and PAST 4.0. A total of 34 species and 1,081 individuals were recorded across five taxonomic groups, dominated by Bacillariophyceae (51.06%), followed by Chlorophyceae (25.44%), Cyanophyceae (10.45%), Euglenophyceae (9.16%), and Chrysophyceae (3.88%). Spatially, phytoplankton abundance peaked at Station 2 (523 individuals). Diversity indices showed moderate variation: Shannon-Wiener (2.837-3.396), Evenness (0.656-0.904), Menhinick (1.443-2.394), and Margalef (4.989-6.099). Palmer Pollution Index (PPI > 20) confirmed high organic pollution. Water variables ranged as follows: temperature, 27.8-30.50C with the mean 28.110C, pH,5.00-6.55(5.93), Dissolved Oxygen, 4.50-6.30 mg/L(5.40 mg/L). Nutrient concentrations ranged from 0.40-0.71 mg/L (PO?), 1.25-3.50 mg/L (SO?), and 3.20-5.80 mg/L (NO?). Phosphate exceeded the NESREA permissible limit (0.10 mg/L), while sulphate significantly varied spatially. The presence of Cyclotella species, Melosira monoliformis and Navicula distans and higher phosphate values are clear indications that pollution is eminent in the area. Generally, Okamini Stream exhibited organic enrichment linked to anthropogenic activities. Regulatory measures are urgently needed to mitigate pollution and protect aquatic biodiversity.