floating marine litter have been identified as introduction pathways for invasive alien species in Europe. More
specifically, aquaculture is the second most important pathway of marine alien
species introduction into European Seas contributing to about 17% of the introductions. On the other hand, the role of
marine litter has been overlooked in the past and is suspected as an important
pathways but currently is less studied.
The recent study
conducted by the University of Oviedo (Portugal), investigated the dispersal of alien invasive species on
anthropogenic litter from mariculture, in the Venetian
lagoon and the Portuguese Algarve region. By collecting fouled stranded
objects, researchers identified eight non-native, invasive species, most of them
originally distributed in the Indo Pacific Region. Most of the invasive alien
species detected, were known to be present in the two sampling areas but the
highly invasive Polychaeta Hydroides sanctaecrucis, native to the
Caribbean, was reported for the first time in the whole Mediterranean and
Eastern Atlantic region.
invasive species often use litter in the ocean as a platform for moving to new
territories. This is not a new phenomenon, as natural debris (dead wood, ash,
etc.) have enabled species to move for millions of years, but the movement of
alien species on litter items is potentially a new problem, because of the
proliferation of floating – mostly plastic – particles. The combination of anthropogenic
litter and mariculture activities is by far less studied, but is an important
dispersal mechanism for invasive alien species in Europe.
species in the European Aquaculture
Marine litter helps the spread of invasive