Elodea nuttallii in Bulgaria
Elodea nuttallii (Hydrocharitaceae: EPPO List of Invasive Alien Plants) is native to North America and has been introduced into the EPPO region as an ornamental species and has since been accidently released from aquariums into the natural environment. E. nuttallii is included in the List of invasive alien species of EU concern (EU Regulation 1143/2014). In Bulgaria, the species has been recorded as naturalised since 2002 and since then, the number of locations where the species is recorded has increased rapidly. In Bulgaria, it invades slow-flowing rivers, lakes, reservoirs, ponds and canals. The species can spread rapidly through vegetative reproduction and growth and can form monospecific stands. Once established the species is difficult to control as even small fragments can form viable populations. The species was first recorded in Bulgaria in the Topolovets River and has since been recorded on the Black Sea Coast and in North east Bulgaria, Sofia region, Vitosha region, Znepole region, West Frontier Mountains, Valley of the Riover Struma, Rhodopi Mountains and Thracian Lowlands. The authors highlight that the Danube River has been a major corridor for the spread of the species in Bulgaria.
Sources
Georgiev V, Tsoneva S, Kenderov L, Truchkova T, Todorov M, Vladimirov V (2019) Distribution of Elodea nuttallii, an invasive alien species of EU concern, in Bulgaria. Phytologia Balcanica 25, 417-423.