Ecological Assessment of Phytoplankton Diversity in Crude Oil-Impacted Aquatic Ecosystems in Bayelsa State, Nigeria

This study assessed the diversity of phytoplankton in selected crude oil-impacted aquatic ecosystems in Bayelsa State, Nigeria. With petroleum exploration being a foundation of the region’s economy, oil pollution has severely affected aquatic life, including phytoplankton—the primary producers in aquatic food webs. Phytoplankton samples were collected during both dry and wet seasons from four water bodies: River Niger (Ayamasa and Okumbiri axes), Taylor Creek (Ikarama axis), and Kolo Creek (Ibelebiri axis) all from the three geographical districts of Bayelsa State. Diversity was analyzed using standard indices such as Simpson, Shannon-Wiener, and Margalef. Results showed significantly higher phytoplankton diversity and abundance during the dry season, particularly at Ayamasa, compared to the wet season. Chlorophyta and Bacillariophyta were the most abundant phyla, with Bacillariophyta showing a high tolerance to pollution. The presence of pollution-indicator species like Euglena sanguinea and Anabaena spiroides in impacted areas suggests ongoing environmental stress. Overall, crude oil pollution influenced phytoplankton community structure, with seasonal variations highlighting the dynamic nature of these aquatic ecosystems. The findings highlight the value of phytoplankton as bioindicators for monitoring water quality and ecological health in oil-impacted regions.