Qualitative and Quantitative Data on Macrobenthic Fauna of the Romanian Sector of the Danube River: 2023 Sampling Campaign (September - October) – PN 23 30 03 03, National Project

This study provides both qualitative and quantitative analyses of macrobenthic fauna, aiming to establish an annual monitoring network and evaluate the conservation status of selected sites. The research was conducted within the framework of the national project “Optimizing the sustainable management of natural resources, enhancing water security, and increasing the resilience of ecosystems in the Lower Danube Basin, impacted by climate change and anthropogenic interventions” (PN 23 30 03 03). In September–October 2023, physicochemical parameters were measured in multiple stations across the Lower Danube and associated branches using EXO multiparameter probes, as part of the annual benthic fauna monitoring program. Sampling covered sectors including Ceatal Izmail (M41–M52.5, Danube km 111.5–114.5), Reni (M63–M67), Gropeni (Danube km 186–196.5), Fermecatu (Danube km 317–325), and Turcescu (Danube km 339–347). Additional measurements were collected from selected stations on the Chilia, Tulcea, and main Danube channels, totaling over 90 stations. The collected data provide spatially detailed profiles of key physicochemical indicators, supporting environmental status assessments and long-term monitoring strategies for the Danube River.