Drifting Nets as a Tool to Achieve Fish Management and Conservation Purposes in the Lower Danube River

Abstract Drift trammel netting is a traditional method for commercial fish catches in the Danube River, especially along the Bulgarian stretch. Potentially, non-commercial or endangered fish species may be caught as bycatch, but no official statistics exist. Recently, freshwater fish populations, including commercial species, have declined. In light of these facts, the study aims to examine recent quantitative fish catches from drift netting in the Lower Danube from a conservation point of view. During the early summer of 2024, 54 transects with drifting trammel nets were performed at two sampling sites on the Lower Danube (Bulgaria). The fishing gear and methodology used were similar to those in commercial fishing. 18 fish species were captured, including one sturgeon species. 9 are under protection in the NATURA 2000 network, and 15 are mentioned in at least one regulatory document. On this basis and for better assessment and conservation, bycatch and discards should be officially registered, and quotas should be considered. As additional output, the presence of Pontic shemaya was confirmed in a new NATURA 2000 site, BG0000530. Thus, it should be included in this site accordingly, since it is the most suitable for its monitoring.