BioBlitz on Invasive Alien Species along the Danube!
- sagnew3
- Jul 18
- 3 min read
For a second year DANUBE4all participated in a BioBlitz survey on invasive alien species (IAS) with the help of citizen science, intended for both professionals and amateurs, as part of Alien CSI BioBlitz initiative, organised at European level (read more here). The BioBlitz surveys in the Danube Region (Bulgaria, Croatia, Romania and Serbia) were conducted in the period 23.05.2025 – 08.06.2025. The survey results will contribute to the implementation of DANUBE4all objectives to improve the ecological status of the river environment and key species, and to empower inhabitants, communities and citizen science.
BioBlitz in Croatia
In Croatia, the BioBlitz event was organised as part of the International Biodiversity Day and National Nature Protection Day by the Nature Protection Agency in Osijek-Baranja County (full member of DANUBEPARKS Network) and was conducted at fishponds in Našička Breznica Village on 24th May, 2025. The findings of IAS (mostly plants) have been reported via the mobile application ‘Invasive Species in Croatia’ maintained by the Croatian Ministry of Environmental Protection and Green Transition. Further information about the BioBlitz event can be found on local social media pages here: Park prirode Kopački rit and Javna ustanova za zaštitu prirode Osječk.
BioBlitz in Bulgaria and Romania
Taking part in the the BioBlitz surveys on IAS in Bulgaria and Romania were volunteers including scientists, students, NGO activists, environmentalists, who joined either as individual participants or as part of a BioBlitz event guided by experts in the Yuzhen Park, Sofia on 8th June, 2025. The sightings of IAS have been recorded via the "iNaturalist" mobile phone application under the project ‘BioBlitz IAS Danube Region 2025’. In addition the ‘Invasive Alien Species in Europe’ app, developed by the EC Joint Research Centre, was used. After validation, the data from this app will be stored directly in EASIN – European Alien Species Information Network. This database supports the implementation of the EU Regulation 1143/2014 on invasive alien species. The citizen science data on aquatic IAS from this year will be also used for the Joint Danube Survey 5 (JDS5) ).
Observations of Invasive Alien Species
A total of 230 observations of 70 taxa were recorded by iNaturalist in the Danube River Basin in Bulgaria and Romania (see results here). Some 33 alien species (12 plants and 21 animals) have been reported, among them 6 IAS of Union concern and 6 aquatic IAS of Danube River Basin concern, including the fish IAS: black bullhead Ameiurus melas, Prussian carp Carassius gibelio, eastern mosquitofish Gambusia holbrooki, pumpkinseed Lepomis gibbosus, and translocated Bulgarian spined loach Cobitis strumicae and black-striped pipefish Syngnathus abaster.
