Distribution map


Danube River expedition 2015


The 4th Danube River expedition


The 4th Danube River expedition on invasive alien species (IAS) was organised in the period from 31 August 2015 – 12 September 2015, within the ESENIAS-TOOLS project.


A total of 34 sites were sampled in the Bulgarian stretch of the Danube River from Vrav, 840 rkm, to Vetren, 395 rkm, of them 20 sites in the Danube River, 6 sites in the lower reaches of the Danube tributaries, and 8 sites in the adjacent standing water bodies. The field sampling was performed from the shore in the section from Vrav to Lom, and by boat from Lom to Vetren.


About 100 samples of epilithic diatoms, benthic macroinvertebrates, molluscs, crayfish, and fish were collected. A high percentage of the recorded species, in particular benthic macroinvertebrates, were alien, and some of them had very high abundance (e.g. Corbicula fluminea, Anodonta woodiana). Newly invaded sites of some alien species of fish (Ameiurus melas, Perccottus glenii) were found (see Species alert section).


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