Portugal reports 75% increase in invasive marine species

A scientific study has revealed that the number of invasive marine species in Portuguese waters has increased by 75% over the last decade. Researchers reported 231 non-indigenous species currently present, up from 133 recorded ten years ago.

The study, led by the Centre for Marine Sciences and the Environment (Mare) and the Aquatic Research Network (Arnet), was published in the journal Marine Pollution Bulletin. The findings include 159 species in mainland Portugal, 81 in the Azores, and 62 in Madeira.

Investigators identified maritime navigation as the primary cause of these introductions. Species are frequently transported through attachment to vessel hulls or via the discharge of ballast water tanks used to maintain ship stability during cargo transport.