Plastic Pollution in Wadis: Investigation at a Hotspot in Wadi Hoqain, Oman

Introduction Plastic pollution is now recognized as a global problem that must also be addressed at the local level. It is important to study not only the marine environment as the final sink but also the sources and pathways within the terrestrial environment. This report presents field investigations on macroplastics conducted in Wadi Hoqain, Oman. While the transport of plastics in perennial rivers has been extensively studied, there remains a lack of knowledge regarding the migration of plastics in ephemeral streams. Methods A popular tourist hotspot was chosen as the study site, where macroplastics were collected, classified, and counted at several downstream locations. An app was used to store data directly online during the fieldwork. Results Plastic caps and lids were the most frequently found items, followed by plastic food wrappers. The major categories showed a decreasing number of items per area in the downstream direction. Discussion The presented findings are examined in the context of the concept of transient storage zones, originally developed for perennial streams. This study demonstrates that the concept can be effectively adapted to explain the unique characteristics of plastic migration in wadis. Conclusion The results of our investigations downstream from the hotspot offer insights into the transport of plastic items along the flow path, which may be relevant to ephemeral streams more broadly.