A bubble Barrier that removes litter from rivers is being applied in the Ave estuary (Portugal) in the framework of the MAELSTROM Project. In order to identify the location where the technology could possibly best be applied and to assess the impact of the litter removal on marine life, MAELSTROM makes use of numerical models. Facing the limited field data and absence of available models, we carried out field campaigns, set-up a hydrological model for the Ave river basin and set-up a hydrodynamic model for the estuarine region. The field studies included a bathymetric survey, short-term (12.5 hours) and long-term (several weeks) campaigns. Aiming to understand the temporal and spatial variation of the flow velocity in the estuary, and particularly in the area where the Bubble Barrier system is planned to be implemented, we have analysed observations from a boat sailing across the estuary (short-term), we have analysed observations at selected locations (long-term) and we have set-up a 3-dimensional (3D) hydrodynamic model to give insight in the flow velocity distribution. Only during the short-term campaigns the river discharge is known, which was relatively low during these campaigns. Since the river discharge is an important condition for the hydrodynamic model, we have only obtained maximal flow velocity maps for low river discharge. For higher river discharge we show a maximal flow velocity observed during a long-term campaign and we estimate maximal flow velocity based on an extreme river discharge.

New solutions for the recovery of marine plastics and litter: The global marine plastic litter challenge comprises an estimated stock of 83 million tonnes of plastic waste accumulated in oceans. The recovery of plastic materials already in the ocean is an arduous and costly task. This is why innovations are urgently needed. The EU-funded MAELSTROM project is bringing together key stakeholders – from research centres and recycling companies to marine scientists and robotic experts – to leverage the integration of complementary technologies for the sustainable removal of marine litter in different European coastal ecosystems. The project will design, manufacture and integrate scalable, replicable and automated technologies, co-powered with renewable energy and second-generation fuel, to identify, remove, sort and recycle all types of collected marine litter into valuable raw materials. Objective: MAELSTROM strives to provide answers and diversified solutions to the complex question to the removal and sustainable treatment of marine litter legacy. MAELSTROM leverages on the integration of complementary technologies for marine litter removal in different European coastal ecosystems, compounded with full-fledged circular economy and societal oriented solutions. In particular, the project (i) sets out a reliable multidisciplinary and scientifically sound approach for the assessment of marine debris distribution and impact on marine life in highly valuable ecosystems and protected areas; (ii) designs and manufactures scalable, replicable and automated technologies, co-powered with renewable energy and second generation fuel, to identify, remove and sort marine litter; (iii) evaluates over time the effectiveness of marine litter removal devices along with their impact on local ecosystems; (iv) integrates different technologies to track, sort and recycle all types of collected marine litter into valuable raw materials for future marketisation; (v) assesses the economic and societal impact of the MAELSTROM solutions providing also a comprehensive life-cycle assessment of the technologies and products; (vi) enhances social awareness about the marine litter issue and engages citizens and stakeholders in MAELSTROM activities; (vii) interplays with similar projects to maximize innovation uptake for marine litter removal within and outside the EU. MAELSTROM is formally supported by a set of key stakeholders committed to sustain its core actions and its follow up activities. The consortium is a tight knit group made of research centers and foundations of excellence in marine life, biology and sustainable energy, AI and robotics, multinational /national recycling companies with certified industrial plants, a market consultancy company, a micro-enterprise and a plastic-focussed NGO.

One of the aim of the MAELSTROM project was to provide a new set of integrated and advanced solutions to identify the typology of marine litter and foremost its traceability from the collection to the treatment phase through innovative app and portal. The Project developed a software and hardware tracking platform for ML data mining and sharing to narrate the in-field organization and testing of marine litter tracking, monitoring and clean up activities. The campaign conducted by Venice Lagoon Plastic Free (VLPF) of marine litter monitoring in the lagoon of Venice in Italy was devised to provide guidance and the feedback required to instruct the technical team's work involved in framing, developing, and fine-tuning the marine litter monitoring service within the MAELSTROM app. The dataset represents the results of four beach litter surveys conducted in the area of the Venice Lagoon in 2021. Data report the number of items identified on the beaches in a 100 m long transect along the beach length. The typology of items is identified using the “G code”, as per the Guidelines and forms for gathering marine litter data: beach and seafloor trawling (Galgani et al., 2021). For more information about the survey see the project deliverable 6.1.

UNO is a underwater images dataset allowing deep-learning networks to localize non-natural objects within underwater images. The dataset consists in 279 videos, 5930 frames, and 10809 labels. UNO is a more consistent and balanced version of the TrashCan image dataset to evaluate models for detecting non-natural objects in the underwater environment. We propose a method to balance the number of annotations and images for cross-evaluation. We then compare the performance of a SOTA object detection model when using TrashCAN and UNO datasets. Additionally, we assess covariate shift by testing the model on an image dataset for real-world application. Experimental results show significantly better and more consistent performance using the UNO dataset.

Both the short-term and long-term campaigns were performed during summer and winter conditions, meaning respectively a low and high river discharge. For the long-term campaigns, instruments were deployed for several weeks: CTD and ADCP.

Both the short-term and long-term campaigns were performed during summer and winter conditions, meaning respectively a low and high river discharge. The short-term campaigns were carried out from a boat during spring tide, anticipating that normally at highest tidal range the highest flow velocities occur. Flow velocity was measured using an Acoustic Doppler Current Profiler (ADCP).

As part of the European MAELSTROM project, microplastic monitoring was carried out to assess the impact of marine cleaning operations. The study focused on two representative sites: Sacca Fisola, within the Venice Lagoon, characterised by high maritime traffic, and Mussel Farm, a coastal area near Cavallino-Jesolo, a former mussel farm. Both sites were monitored every six months and divided into before and after cleaning activities performed by the Seabed Robotic Cleaning Platform (autumn 2022 and spring 2023 for the Sacca Fisola site and spring 2023 for the Mussel Farm site). This innovative robotic system has been designed to remove macro-litter from the seabed. Among the different matrices analysed, particular attention was paid to the biota, with the study of fish species representative of the North Adriatic area, both lagoon and coastal. The species analysed included mullet (Liza sp.), sea bream (Sparus aurata), dauphin (Atherina boyeri) and sole (Solea solea). The main objective was to assess whether the removal of macro plastics from the seabed by the robot was correlated with a reduction in microplastics in the fish themselves, thus contributing to an understanding of the effectiveness of cleaning operations not only on visible debris, but also on the microscopic particles that can be accidentally ingested by these organisms.

As part of the European MAELSTROM project, microplastic monitoring was carried out to assess the impact of marine cleaning operations. The study focused on two representative sites: Sacca Fisola, within the Venice Lagoon, characterised by high maritime traffic, and Mussel Farm, a coastal area near Cavallino-Jesolo, a former mussel farm. Both sites were monitored every six months and divided into before and after cleaning activities performed by the Seabed Robotic Cleaning Platform (autumn 2022 and spring 2023 for the Sacca Fisola site and spring 2023 for the Mussel Farm site). This innovative robotic system has been designed to remove macro-litter from the seabed. Among the matrices analysed, particular attention was paid to bivalves, which are used as bio-indicators. Several species, including Mytilus galloprovincialis, Magallana gigas and Ostreola stentina, were sampled to monitor the accumulation of microplastics (MP) in them. The main objective of the study was to assess whether the removal of macrolitter resulted in a reduction of microplastics in the environment.

As part of the European MAELSTROM project, microplastic monitoring was carried out to assess the impact of marine cleaning operations. The study focused on two representative sites: Sacca Fisola, within the Venice Lagoon, characterised by high maritime traffic, and Mussel Farm, a coastal area near Cavallino-Jesolo, a former mussel farm. Both sites were monitored every six months and divided into before and after cleaning activities performed by the Seabed Robotic Cleaning Platform (autumn 2022 and spring 2023 for the Sacca Fisola site and spring 2023 for the Mussel Farm site). This innovative robotic system has been designed to remove macro-litter from the seabed. Among the different matrices analysed, particular attention was paid to the biota, with the study of fish species representative of the North Adriatic area, both lagoon and coastal. The species analysed included mullet (Liza sp.), sea bream (Sparus aurata), spiny dogfish (Squalus acanthias) and sole (Solea solea). The main objective was to assess whether the removal of macro plastics from the seabed by the robot was correlated with a reduction in microplastics in the fish themselves, thus contributing to an understanding of the effectiveness of cleaning operations not only on visible debris, but also on the microscopic particles that can be accidentally ingested by these organisms.

As part of the European MAELSTROM project, microplastic monitoring was carried out to assess the impact of marine cleaning operations. The study focused on two representative sites: Sacca Fisola, within the Venice Lagoon, characterised by high maritime traffic, and Mussel Farm, a coastal area near Cavallino-Jesolo, a former mussel farm. Both sites were monitored every six months and divided into before and after cleaning activities performed by the Seabed Robotic Cleaning Platform (autumn 2022 and spring 2023 for the Sacca Fisola site and spring 2023 for the Mussel Farm site). This innovative robotic system has been designed to remove macro-litter from the seabed. Among the matrices analysed, particular attention was paid to bivalves, which are used as bio-indicators. Several species, including Mytilus galloprovincialis, Magallana gigas and Ostreola stentina, were sampled to monitor the accumulation of microplastics (MPs) in them. The main objective of the study was to assess whether the removal of macrolitter resulted in a reduction of microplastics in the environment.