The Role of Leeches in Assessing Biodiversity and Water Quality in Irrigated Ecosystems

Abstract

This study reviews the role of leeches (Hirudinea) in aquatic ecosystems and examines their distribution patterns in collector-drainage networks in relation to biodiversity conservation and water quality assessment in agricultural landscapes. Global agricultural intensification has significantly reduced natural wetlands while promoting the development of artificial aquatic habitats, including irrigation canals, reservoirs, and drainage systems. Although these artificial environments cannot fully replace natural wetlands, they provide alternative habitats for various aquatic organisms, including leeches. The research analyzes the main environmental factors influencing leech distribution, such as hydrological conditions, water physicochemical characteristics, mineralization levels, and anthropogenic impacts. Particular attention is given to the relationship between water mineralization and the species composition, abundance, and spatial distribution of leech populations. The findings indicate that increasing salinity levels significantly affect the occurrence and reproductive capacity of freshwater leech species. The study evaluates the ecological and economic impacts of leeches on livestock production and land reclamation systems in the Mughan Plain. The results show that uncontrolled leech populations may harm animal health and reduce the efficiency of drainage infrastructure. The study demonstrates that integrated management strategies combining hydraulic engineering solutions, preventive measures, and continuous ecological monitoring are more effective than individual control methods for sustainable leech management.