On 4th and 5th June 2021, Blue World Institute, one of ECOSS project partners, has held a workshop on topic of marine litter monitoring and integration of such monitoring programs into the Ecological Observatory System in the Adriatic (ECOAdS), developed by the ECOSS project. Participants from 14 organizations, including MPAs, NGOs, research institutes, public services and private sector, have gathered in Veli Lošinj to exchange experiences, practice various marine litter monitoring methods and discuss options for integrating data about marine litter with other oceanographic and ecological data through the ECOAdS. The first day was dedicated to presentations and discussions. During this day, the ECOAdS web portal and its underlying conceptual framework were presented in detail, exploring numerous links between marine litter data and other oceanographic and ecological parameters. On the second day, a clean-up action was conducted on a beach in Veli Lošinj, during which methodologies for collection of data about marine litter presence and effectiveness of its removal were demonstrated. After many months of online-only meetings and workshops, it was a real pleasure to have an opportunity for some hands-on experience exchange. We wish to thank everyone for their participation and Ocean Conservancy for providing support in organizing the clean-up.