An LC-MS-Based Molecular Networking Proof-of-Concept for Revealing Ecological Functional Dynamics in Nylsvley Ramsar Wetland Waters.

Wetlands are unique ecological niches that support highly specialized ecosystems, yet their functioning is strongly influenced by surrounding human activities. Increasing settlement around Nylsvley, a Ramsar-designated wetland has resulted in observable ecological changes. This study presents a comprehensive chemical profiling of water from two sites; Jacana Hide Site (JHS) and Site 3 (S3) sampled during dry and wet seasons. Untargeted LC-MS combined with molecular networking revealed clear chemical differences between sites, with JHS showing greater chemical variability than S3. Many detected compounds could not be annotated due to current database limitations. Among the identified compounds, several anthropogenic contaminants were detected, including plastic-associated fatty acid amides (erucamide and oleamide), phthalates and a UV-filter 2-hydroxy-4-methoxybenzophenone, which may pose ecological risks to aquatic organisms. In addition, alkaloids commonly associated with tobacco and opium use were also observed, suggesting potential wastewater-derived inputs into the wetland system. Molecular networking also showed a notable shift in the chemical composition of the investigated sites before and after rainfall. Overall, this work serves as a proof of concept, providing an initial assessment of the chemical status of the Nylsvley wetland and highlighting potential toxicological risks associated with emerging contaminants.