Pathways of introduction of marine alien species in Europe and the Mediterranean – a possible undermined role of marine litter

Floating marine litter is a potentially important pathway/vector of primary introduction or of further (secondary) spread of alien species. The current knowledge on the pathways of introduction of alien marine species in Europe was reviewed, focusing specifically in the Mediterranean, and the potential role of floating marine litter as a primary or secondary pathway was investigated. The trend of new introductions of alien species in Europe, and in the Mediterranean Sea in particular, has been increasing, reaching ~200 new species introductions per decade. Shipping and corridors are the most important pathways in Europe and the Mediterranean Sea (shipping is the most important overall in Europe but the Suez Canal is the most important in the Mediterranean). The impact of floating marine litter on biological invasions is difficult to measure and compare with other sources such as shipping or transportation on natural motile hosts. However, the availability of floating litter, mostly plastics, has become huge, offering substantial rafting opportunities for encrusting fauna and flora. We found that 81% of the species having been reported to be introduced in the Mediterranean Sea by a different pathway, might have been introduced by marine litter or could use litter for further expanding their range.

KATSANEVAKIS Stylianos Marios;  CROCETTA Fabio; 

2017-04-06

CIESM

JRC90466