Three invasive alien freshwater mussel species of concern to the Danube River basin (DRB) are found in Bulgaria.

The Asian clam Corbicula fluminea originates in Central and Southeast Asia. In Bulgaria, the first specimens were recorded in 2001 in the Danube River, and in 2004, in the Iskar River. Currently, the species is found along the entire Bulgarian section of the Danube River, and has been rapidly spreading upstream of the Danube tributaries. It has also been found in some reservoirs in the Danube River and Aegean Sea basins, reaching an altitude from 0 to 525 m a.s.l. Characterised by a plankton larval stage.

The native range of the Chinese pond mussel Sinanodonta woodiana includes Southeast Asia. The species was first recorded in Bulgaria in 2005 in the Danube River. Currently, it is found in the entire stretch ofthe Danube River, and has spread upstream of its tributaries from 0 to more than 100 m a.s.l. It has also been reported from several reservoirs. The larvae are parasitic – glochidia, using different fish species as hosts.

The quagga mussel Dreissena bugensis originates in the Dnieper-Bug Liman. In Bulgaria, the first specimens were found in 2005 in the Danube River. Currently, it is found along the entire Bulgarian stretch of the river, and in the reservoirs Ogosta and Asparuhov Val, from 0 to 200 m a.s.l. Characterised by planktonic larvae and attached adult forms. The mussels attach to hard substrates with the aid of byssal threads.

Information about the invasive alien species diagnostic features, biological and ecological traits, distribution, pathways of introduction and spread and impact in Bulgaria can be found in:

Hubenov Z., Trichkova T. 2012. Freshwater mussels in Bulgaria. Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 12 pp. (In Bulgarian and English)

Хубенов З., Тричкова Т. 2012. Сладководните миди на България. Институт по биоразнообразие и екосистемни изследвания, Българска академия на науките, 12 стр. (на български и английски език)

Further information about the mussel species of the genus Dreissena can be found on the website: http://dreissena.info/

Sightings of the three invasive alien freshwater mussels to Bulgaria can be recorded with the ‘Invasive Alien Species Europe’ app updated for the Danube River basin  >>>