Map of the 16 ports and marinas surveyed during the first INVASIONS field campaign (4-24 April 2026).

From 4 to 24 April 2026, the INVASIONS research team successfully completed its first large-scale field survey across 16 ports and marinas covering the Greek Ionian Sea.

The campaign expanded beyond the initially planned coverage and included sites in Zakynthos, Corfu, Igoumenitsa, Lefkada, Mytikas, Astakos, Mesolongi, Itea, Patra, Kylini, Katakolo, Pylos, Kalamata, Xylokastro, Kiato and Corinth. This broad spatial coverage allowed the project to investigate key introduction hotspots for marine non-indigenous species across the wider Ionian region.

At each port or marina, the team carried out Rapid Assessment Surveys (RAS) at 10 selected sampling points. These surveys focused on the visual assessment of target habitats and the collection of biological material for further investigation.

In parallel, the field campaign included:

• collection of specimens for species identification and the development of a DNA barcode reference library;
• collection and filtration of more than 2,000 litres of seawater for eDNA metabarcoding; and
• collection of bulk samples from different surface types for bulk DNA metabarcoding.

These combined approaches will support the detection of marine non-indigenous species through both conventional and molecular methods, while also improving knowledge of species’ distributions and strengthening future monitoring capacity in the region.

Among the key goals of this first campaign are the documentation of new records of non-indigenous species and the update of the alien biodiversity inventory for the Greek Ionian Sea.

The fieldwork was conducted by PhD candidates Ioannis Rallis and Markos Digenis, Dr. Eirini Gratsia, and Principal Investigator Professor Vasilis Gerovasileiou.

This first field campaign marks an important milestone for the project and provides the basis for the next stages of laboratory analysis, data integration, and the development of a standardised monitoring framework for marine non-indigenous species in hotspot areas of the Ionian Sea.

Main picture: Map of the 16 ports and marinas surveyed during the first INVASIONS field campaign (4-24 April 2026).