Litter from mariculture contribute to the dispersal of invasive species in Europe


Monday, 30 April 2018

Aquaculture and 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.

Non-indigenous 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.

Useful links

Non-native species in the European Aquaculture

Marine litter helps the spread of invasive alien species