Monitoring plankton biodiversity is a key tool for assessing the status of marine ecosystems, particularly in port areas subject to strong anthropogenic pressure and the introduction of non-indigenous species (NIS) through ballast water. In the Port of Genoa, the presence of the non-indigenous copepod Paracartia grani grani (Sars G.O., 1904) has been known since 1997.

In accordance with Descriptor 2 of the Marine Strategy Framework Directive (2008/56/EC), monitoring was conducted at Marina Fiera, Genoa, with two main objectives: (i) to assess the presence and seasonal variability of P. grani grani, and (ii) to test the effectiveness of a screening protocol based on optical imaging (ZooScan) for detecting NIS.

Zooplankton samples were collected on a monthly basis during the 2024–2025 period, along with the main physicochemical parameters of the water column. Samples were subsequently digitised, and taxonomic identification was performed using a semi-automated workflow combining artificial intelligence algorithms with expert visual validation.

Our results confirm the seasonal presence of P. grani grani from August to October period, in agreement with previous observations, while the species was absent during the rest of the year. This seasonal pattern suggests the possible presence of resting stages in the sediments, which represent a potential target for future studies.

The semi-automated approach allowed the analysis of the entire dataset, substantially reducing processing time compared with traditional methods and producing a permanent digital archive. These results highlight the potential of optical imaging and semi-automated classification as a rapid and efficient tools for monitoring NIS in port environments.