An overview of the distribution and ecology of the alien cyanobacteria species Raphidiopsis raciborskii, Sphaerospermopsis aphanizomenoides and Chrysosporum bergii in Europe

Cyanobacteria can form blooms and pose a threat to the functioning of freshwater ecosystems. Cyanobacterial invasions are expected to increase due to climate change. Alien species cause a decline in biodiversity by displacing native species, lead to extinctions, affect food webs, and produce cyanotoxins which potentially impact the environment and human health. Three species, Raphidiopsis raciborskii, Sphaerospermospis aphanizomenoides and Chrysosporum bergii, are considered non-native to European waters. Recently, they have expanded their native habitats and become established in temperate lakes. In this article, we provide a detailed overview of the countries where they are distributed and the occurrence of the blooms in Europe. We discuss the biotic and abiotic environmental factors that influence their establishment, as well as the characteristics of the species that make them so adaptable in non-native habitats. Understanding the interplay of these factors will allow us to better recognise patterns of invasiveness and predict their future threats to ecosystems.