Impact of seasonal changes in physicochemical water parameters on the morphometric and meristic characteristics and phytoplankton community structure associated with Nile tilapia [Oreochromis niloticus (Linnaeus, 1758)] in the Great Kwa River

• Authors: Inyang Paul Ekpo , Paul Bassey Ekpo , Precious Archibong Edem , Emmanuel Lekwa Ezikpe
• Languages of publication: EN

Abstracts

EN

This study investigates how physicochemical water parameters affect Nile tilapia (Oreochromis niloticus) morphometrics, meristics, and phytoplankton diversity in the Great Kwa River, with implications for environmental management and fisheries sustainability. Water quality variables temperature, pH, dissolved oxygen, conductivity, salinity, total dissolved solids, alkalinity, ammonia, biochemical oxygen demand, chemical oxygen demand, and total bicarbonate were systematically measured over four months (February, March, May, and June) encapsulating both dry and wet seasons. Concurrently, morphometric and meristic traits of Nile tilapia were recorded. Significant correlations (P < 0.05) emerged between water quality parameters and the fish’s physical characteristics. Notably, higher temperatures correlated negatively with standard length and dorsal fin measurements, suggesting thermal stress may hinder tilapia growth. Conversely, increased alkalinity showed positive relationships with head length and first dorsal fin size, indicating habitat chemistry influences anatomical development. Phytoplankton diversity indices also fluctuated in response to changing physicochemical conditions. Species richness varied between 5 and 10 taxa; the Shannon-Wiener diversity index ranged from 1.26 to 2.71, while Pielou’s evenness index fluctuated from 0.63 to 0.82. These variations reflect how environmental factors modulate phytoplankton community structure, affecting ecosystem productivity and fish food resources. The findings highlight complex interactions among physicochemical water conditions, Nile tilapia morphology, and phytoplankton diversity in the Great Kwa River. This underscores the critical need for ongoing water quality monitoring and proactive ecosystem management to preserve aquatic biodiversity and sustain Nile tilapia populations vital for local fisheries and livelihoods.

Keywords

EN

Nile tilapia; Oreochromis niloticus; Physicochemical parameters; morphometrics; phytoplankton diversity

Discipline

• FISHERIES: FISHERIES

• Publisher: Scientific Publishing House „DARWIN”
• Journal: World News of Natural Sciences
• Year: 2026
• Volume: 64
• Pages: 21-44

Contributors

author

Inyang Paul Ekpo

• Department of Fisheries and Aquaculture, Faculty of Agriculture, University of Calabar, Calabar, Cross River State, Nigeria

author

Paul Bassey Ekpo

• Department of Genetics and Biotechnology, Faculty of Biological Science, University of Calabar, Calabar, Cross River State, Nigeria

author

Precious Archibong Edem

• Department of Genetics and Biotechnology, Faculty of Biological Science, University of Calabar, Calabar, Cross River State, Nigeria

author

Emmanuel Lekwa Ezikpe

• Department of Genetics and Biotechnology, Faculty of Biological Science, University of Calabar, Calabar, Cross River State, Nigeria

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• Document Type: article