In the Ave River estuary, monitoring of Floating Macro-Litter (FML) was undertaken before (June 2021 - December 2023) and after the installation of the Bubble Barrier remediation technology in order to assess its effectiveness.

Evaluation of FML followed standard European guidelines (Hanke et al., 2013, 2023) and was conducted through visual monitoring to assess the diversity and relative abundance of debris in the area. Monitoring campaigns were carried out monthly from June 2021 to December 2024. FML observations were performed using binoculars (during ebb tide at three designated locations in the estuary—downstream, midstream, and upstream.

All three observation points were positioned at the same elevation along the estuary margin, approximately 2 meters above the water surface (mean sea level), ensuring a consistent viewing angle for reliable comparisons between locations. Although some FML objects may have been partially obscured by wind-generated ripples or small waves from passing boats, this impact was minimized as observations were conducted on calm days with high visibility.

More details on the methodology can be found in D5.4

More details on the results can be found in D2.4.