Spatio-seasonal variation of phytoplankton composition and some physico-chemical parameters of the lower Taylor Creek, Bayelsa State, Nigeria

Phytoplankton communities play a crucial role in aquatic ecosystems, serving as primary producers and indicators of water quality. This study investigates spatio-seasonal variation of phytoplankton composition and some physico-chemical parameters of the lower Taylor Creek, Bayelsa State, Nigeria. Phytoplankton net of 55 µm mesh size was towed along the Creek, while various physico-chemical parameters, including temperature, pH, total dissolved solids, electrical conductivity, total suspended solids, chlorine, transparency, alkalinity, turbidity, dissolved oxygen, biological oxygen demand and some nutrients (phosphate, nitrate and ammonia) concentrations were analyzed once monthly from July-September 2024 (Wet season) and December - February 2025 (Dry season) following standard methods. A total of 690 phytoplankton made up of 36 species were recorded during the study period. The percentage composition of each phytoplankton group was as follows: Chlorophyta 11 species (36.81 %), Pyrrhophyta 8 species (28.11 %), Bacillariophyta 7 species (24.20 %), Chrysophyta 5 species (8.11 %), Cyanophyta species 3 (1.59 %), Euglenophyta 1 specie (0.57 %), Xanthophyta 1 specie (0.43 %) and Rhodophyta 1 specie (0.14 %). Physico-chemical parameters reveal Chlorine (1.21±0.3 mg/L), transparency (0.31±0.04 m), and turbidity (19.20±7.83 mg/L) while phosphate, nitrate and ammonia exceeded permissible limit. Wet season recorded high nitrate (0.19 mg/L). and phosphate (0.08 mg/L) given rise to indicator species like Navicular rostella, Nitzschia closterium Chlorolella sp, Pediastrum sp, Prorocentrum sp. Therefore, the study highlighted changes in species composition and effectively reflect variations in physico-chemical and nutrients parameters during wet season, reinforcing the importance of phytoplankton monitoring in environmental assessments will keep biological integrity.