Identified invasion pathways of aquatic invasive alien species of EU concern to Finland with a case study of pumpkinseed (Lepomis gibbosus)

Authors

• Miia Jauni Natural Resources Institute Finland
• Erja Huusela Natural Resources Institute Finland
• Terho Hyvönen Natural Resources Institute Finland
• Sanna Kuningas Natural Resources Institute Finland

Abstract

Invasive alien species (IAS) are a major threat to biodiversity globally. Recognition of invasion pathways is crucial for prohibiting the introduction and spread of IAS. We reviewed invasion pathways identified for the aquatic IAS of European Union (EU) concern to Finland. Of the 36 aquatic IAS of EU concern, four (Lepomis gibbosus, Pacifastacus leniusculus, Elodea nuttallii and Lysichiton americanus) have established into nature. Escape from confinement, especially from aquariums, was recognized as the most common invasion pathway. Contamination, stowaways and corridors were regarded mainly as potential invasion pathways but rarely detected in Finland. Intentional release has been a known invasion pathway for few IAS including pumpkinseed (L. gibbosus), which has extended its distribution in southwestern Finland during the last ten years. The first observations of pumpkinseed were conducted by citizens, underlining the importance of public awareness raising as a management measure for all aquatic IAS. In addition, effective monitoring of the distribution of aquatic IAS using both citizen science and systematic research should be ensured.