Distribution map


JDS4 IAS Programme – Bulgaria


Alien CSI participants took part in the Joint Danube Survey 4 (JDS4) in 2019. Considering the importance of the invasive alien species (IAS) in terms of implementation of the EU Water Framework Directive 2000/60/EC, the International Commission for the Protection of the Danube River (ICPDR) had designed an individual IAS programme in the frame of JDS4, which was conducted at national levels. The updated smartphone application ‘Invasive Alien Species Europe’ has been tested during the survey by recording the IAS of Danube River basin (DRB) concern in Bulgaria, Serbia and Hungary.


In Bulgaria, the sampling was conducted in July – October 2019, during five expeditions, at 82 sites in the Danube River, the tributaries, and the adjacent standing water bodies (canals, lakes, marshes, and reservoirs). The samples were collected by various methods: a beach seine, dip net and gill nets for fish, dredging from a boat and from the shore for molluscs, and LiNi traps for crayfish.


Fourteen species (7 benthic invertebrates and 7 fish species) were identified as IAS of EU and DRB concern. The magnificent bryozoan Pectinatella magnificahas been recorded for the first time in the Bulgarian shoreline zone of the Danube River. In terms of species richness, the percentage of IAS reached up to 12% in benthic invertebrates and 16% in fish, but at certain sites the IAS dominated in number of species and in abundance. The integrated biocontamination by type of water bodies ranged from moderate, indicating ‘moderate’ ecological status, in the shoreline zone of the Danube River, from moderate to high in the canals and lakes adjacent to the Danube River, to severe (‘bad’ ecological status) in the Danube tributaries, and severe in the studied reservoirs.


A total of 56 records of 12 IAS, of which four species of EU concern and eight species of DRB concern, were recorded at 33 sites, using the ‘Invasive Alien Species Europe’ app.