Suspended sediment plays a crucial role in the transport of both essential and harmful chemical species throughout aquatic ecosystems, as well as influencing their geomorphology. Despite significant progress in remote and in situ sensing, there remains a lack of suitable on-site instruments to directly sample suspended sediment and associated chemical species. To address this gap in capability, we have developed the pumped active suspended sediment (PASS) sampler, designed for autonomous on-site suspended sediment sampling in a range of aquatic environments. The first prototype of the PASS sampler was presented at the 2017 SETAC Conference on the Gold Coast in Queensland, and this presentation serves as an update on progress in the development and evaluation of this technique. Specifically, we have optimised the PASS sampler to measure gully sediment discharge in Great Barrier Reef catchments, analyse catchment flow run-off, monitor sediment movement in estuarine seagrass beds, and assess the potential contribution of road run-off as a source of sediment and associated pollutants to vulnerable ecosystems.
The data collected from these PASS sampler applications underscore the importance of empirical measurements in addressing fundamental research questions. Notably, the PASS sampler has played a pivotal role in facilitating the development of preliminary sediment and nutrient budgets for experimental gully remediation projects within the catchments of the Great Barrier Reef. Furthermore, the sampler has proven invaluable in tracking sediment movement across landscapes and has been effectively deployed in remote and high-risk environments.
Our findings emphasize the necessity of employing direct measurement techniques to advance our understanding of suspended sediment dynamics and associated chemical processes. The PASS sampler represents a significant step forward in expanding the range of available tools for direct suspended sediment measurement and monitoring, contributing to a more comprehensive assessment of chemical transport within aquatic systems.