Environmental DNA signatures as a tool to trace the groundwater contamination mechanisms and its associated biodiversity; Applications, limitations and future directions

Environmental DNA (eDNA) signatures are indicative of various conditions in nature. Groundwater systems are vital for diverse ecosystems, presenting unique challenges and opportunities for environmental DNA (eDNA) applications. Ecosystem monitoring, conservation management, and biodiversity evaluation in groundwater-dependent ecosystems (GDEs) rely heavily on eDNA. Groundwater eDNA sources, including plant and animal life, are discussed in this article, along with their applications in determining salinity, water quality, and ecosystem dynamics. In groundwater ecosystems, eDNA is invaluable in detecting species that are otherwise difficult to monitor due to the subterranean nature of the habitat. Interpretation limitations (e.g. lack of reference databases) and technical challenges (e.g. contamination, extraction and detection techniques) are key concerns in GDE. The review also suggests numerous future possibilities, such as integrating eDNA with other techniques like aquifer matrix, hydrogeochemistry, isotopes, and hydrological modeling to improve our understanding of groundwater ecosystems.