Population Dynamics of Freshwater Snails in Relation to Physicochemical Parameters in Hayin Gada Stream of Dutsin-Ma, Katsina State, Nigeria

Abstract

Freshwater ecosystems are sensitive to variations in physicochemical parameters that influence the abundance and distribution of aquatic organisms, including freshwater snails, which are key bioindicators and intermediate hosts of schistosomes. This study assessed the physicochemical properties of Hayin Gada Stream, Dutsin-Ma LGA, Katsina State, Nigeria, and their relationship with snail abundance and distribution. Monthly sampling was conducted from March to May 2024 at four stations representing human contact and irrigation sites. Snails were collected by hand-picking and scooping, identified to species level, and quantified, while water samples were analysed for temperature, pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), turbidity, total dissolved solids (TDS), and conductivity following APHA (2012) standards. Results showed temperature (23.67–27.33 °C), pH (6.17–6.83), DO (7.00–8.33 mg/L), and BOD (1.50–2.00 mg/L) were within WHO permissible limits. Turbidity (20–48 NTU) and TDS (216–627 mg/L) indicated moderate organic and ionic content. Statistical analysis revealed significant spatial variation in temperature (p = 0.021), while other parameters showed no significant differences (p > 0.05). Three snail taxa, Melanoides, Bellamya, and Clams were identified, with Melanoides being dominant (41%), followed by Bellamya (31%) and Clams (28%). Snail abundance correlated negatively with temperature and pH, but positively with DO and BOD, suggesting physicochemical influences on population structure. The study concludes that Hayin Gada Stream sustains moderate biodiversity under favourable ecological conditions. Continuous monitoring of snail populations alongside water quality indices is recommended to detect early environmental degradation and manage schistosomiasis transmission risk.