Habitat suitability modelling for predicting potential habitats of freshwater snail intermediate hosts in Omo-Gibe river basin, Southwest Ethiopia

In spite of considerable progress made in the prevention and control of schistosomiasis and other snail-borne diseases, transmission has intensified in some endemic areas as a result of land-use and climate changes. We used decision tree models and multivariate analysis to identify factors affecting the occurrence and abundance of medically important freshwater snail intermediate hosts in the Omo-Gibe river basin, Ethiopia. The models were based on a dataset of 140 samples collected from lakes, wetlands, rivers, dam reservoir shores and irrigation canals. A total of 1866 freshwater snails belonging to four genera and seven species were collected. Biomphalaria pfeifferi, Lymnaea natalensis and Bulinus globosus had fair to moderate predictive performance based on Kappa statistics (ĸ > 0.2), indicating that these species have clear environmental requirements within the habitat gradient studied. The most important variables influencing the abundance and occurrence of snail species were the presence of predator and competitor, canopy cover, type of water body, waste dumping and water pH. In conclusion, snail species occurred less frequently and in smaller numbers in water bodies with minimal human disturbances. Therefore, preventing human disturbance in water bodies may enhance aquatic biodiversity, thereby increasing the abundance of snail predators and competitors. Preventing the pollution of these ecosystems is essential to maintain their ecological integrity and sustain the ecosystem services they provide to local communities.