MAELSTROM Objective 1: Characterization of major sources of marine litter and macro-plastic, numerical modelling and field campaigns to support litter removal at the demo sites - archive
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.
Field campaigns in the Ave River basin (Portugal)
The MAELSTROM Project performed a literature survey includes existing databases on marine litter data on the water column, sea floor, estuaries, rivers and beaches. Specifically, the European/Regional Seas review is based on existing publications while the study areas review is based on existing publications and raw data, when available. The review intends to provide the knowledge-base on the characteristics, sources and pathways of marine litter in the two demo sites of the lagoon of Venice (Italy) and the Ave River estuary (Portugal). Specifically, the review aims at: ● improving the understanding of the amounts and types of marine litter occurring in Europe and in particular in the study areas; ● improving the understanding of the main sources and pathways of marine litter in Europe and in particular in the study areas; ● supporting the definition of the input data and assumptions related to marine litter to be used in numerical models of marine litter spatial distribution. To achieve this objective, we assume the following constraints: ● the main focus is on macro-litter; ● the review has a geographic scope focused on the study sites; ● marine litter literature has been analysed to indicate the most probable sources and amount. Here the results related to the Adriatic Sea subregion that is characterised by the presence of many sources of marine litter, including large rivers, big coastal cities, touristic facilities, heavy shipping traffic, intense commercial fisheries and mussel farming.
Major sources of marine litter and macro-plastic in the Adriatic Sea
An automated cable-robot on a platform that removes litter from the sea bed is being applied in demo sites near Venice (Italy) 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. The applied numerical tool consists of a three-dimensional hydrodynamic model that reproduces the water current evolution in the domain of the case study area. While the focus of the project is the Venice lagoon and the Gulf of Venice, the study covers the whole Adriatic Sea, including the sources of marine litter coming from the whole of the Adriatic coastline. The distribution of the marine litter in the Adriatic Sea was assessed by performing the numerical simulations, considering both the land based marine litter sources (rivers and cities), as well as marine sources (aquaculture) using the hydrodynamic model SHYFEM (for more information see the project deliverable D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites).
Bottom density of marine macro litter in the Adriatic Sea
The MAELSTROM Project performed a literature survey includes existing databases on marine litter data on the water column, sea floor, estuaries, rivers and beaches. Specifically, the European/Regional Seas review is based on existing publications while the study areas review is based on existing publications and raw data, when available. The review intends to provide the knowledge-base on the characteristics, sources and pathways of marine litter in the two demo sites of the lagoon of Venice (Italy) and the Ave River estuary (Portugal). Specifically, the review aims at: ● improving the understanding of the amounts and types of marine litter occurring in Europe and in particular in the study areas; ● improving the understanding of the main sources and pathways of marine litter in Europe and in particular in the study areas; ● supporting the definition of the input data and assumptions related to marine litter to be used in numerical models of marine litter spatial distribution. To achieve this objective, we assume the following constraints: ● the main focus is on macro-litter; ● the review has a geographic scope focused on the study sites; ● marine litter literature has been analysed to indicate the most probable sources and amount. Here the results related to the NW Portuguese coastal area.
Marine Litter on the NW Portuguese coast
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 hydrodynamic numerical model for the Ave estuary was implemented using D-Flow Flexible Mesh (D-Flow FM), which is the hydrodynamic module of the Delft3D Flexible Mesh Suite developed by Deltares (for more information see the project deliverable D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites).
Hydrological model results for the Ave River basin in Portugal
Hydrological model results for the Ave estuary in Portugal
n the framework of the MAELSTROM Project, the specific objective for the Portuguese demo site Ave estuary was to understand the flow dynamics in the estuary associated with river discharge and tides, in order to estimate the transport and fate of litter and to help the detailed design of the Bubble Barrier system. Since very limited observations and no flow velocity observations were available for the Ave estuary, Deltares carried out the following activities: - A bathymetric survey was carried out to obtain bed level in the entire estuary, needed for both the set-up of the hydrodynamic model and to prepare for the implementation of the Bubble Barrier system. - Flow velocity and density variation were measured during a tidal cycle (about 13 hours) at selected locations (short-term), during the summer and the winter. - For several weeks (long-term) flow velocity and density were monitored at two locations in the estuary. - In absence of observations, a hydrological model was set-up to obtain river discharge. - Finally, a hydrodynamic model was set-up to obtain flow velocity fields in the area of interest for different tidal and river discharge conditions. This dataset consists in a time series of daily discharge in the second tab. While, the first tab gives an overview of the location and Ave catchment in Portugal. The time series was obtained by running a hydrological model that was set-up for the catchment. Using European data like rainfall, the river discharge was calculated. For more details, see MAELSTROM deliverable 2.2.
Simulated discharge Ave river (Portugal)
Within the MAELSTROM project two complementary marine litter removal technologies are developed and tested. An automated seabed cleaning platform has been developed with a cable-robot able to remove marine litter from the seafloor at demo locations in the coastal area near Venice (Italy), and a Bubble Barrier system will be implemented to remove marine litter from the water column in the Ave estuary (Portugal). In order to select locations where the technologies can best be applied and to assess the impact of the litter removal on marine life, we have set-up and applied numerical models. Furthermore, results of field observations that were carried out in the framework of MAELSTROM are analysed and are put into context using the numerical modelling results.
MAELSTROM Objective 1: Characterization of major sources of marine litter and macro-plastic, numerical modelling and field campaigns to support litter removal at the demo sites
© MAELSTROM - Smart technology for MArinE Litter SusTainable RemOval and Management funded by the European Union, Programme H2020-EU.3.2.5.1. Grant agreement No 101000832. https://doi.org/10.3030/101000832.
Fantina Madricardo, Vanessa Moschino, ANTONIO PETRIZZO, Taha Lahami, and Valentina Grande. "MAELSTROM Objective 1: Characterization of major sources of marine litter and macro-plastic, numerical modelling and field campaigns to support litter removal at the demo sites - archive." ROHub. Mar 13 ,2025. https://doi.org/10.24424/dt8r-2q65.
Marine litter sources and numerical models
Environment/Natural resources/Water/Oceans
Within the MAELSTROM project two complementary marine litter removal technologies are developed and tested.
MAELSTROM Objective 1: Characterization of major sources of marine litter and macro-plastic, numerical modelling and field campaigns to support litter removal at the demo sites - archive.
An automated seabed cleaning platform has been developed with a cable-robot able to remove marine litter from the seafloor at demo locations in the coastal area near Venice (Italy), and a Bubble Barrier system will be implemented to remove marine litter from the water column in the Ave estuary (Portugal). In order to select locations where the technologies can best be applied and to assess the impact of the litter removal on marine life, we have set-up and applied numerical models.
Economy, business and finance/Economic sector/Chemicals/Synthetic and plastic chemicals
Ghezzo, M., MOSCHINO, V., Galvez, D., Mira Veiga, J., Bocci, M., Iglesias, I., Vieira, L., Sousa Pinto, I., Antunes, S. C., & Correia, A. M. (2021). D2.1 Report on the characterization of major sources of marine litter and macro-plastic in the demo sites. MAELSTROM Project. https://doi.org/10.5281/zenodo.14920205
D2.1 Report on the characterization of major sources of marine litter and macro-plastic in the demo sites
Buschman, F. A., Iglesias, I., Ghezzo, M., McKiver, W., De Pascalis, F., Zaggia, L., Boisgontier, H., & Tiessen, M. (2023). D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites. MAELSTROM Project. https://doi.org/10.5281/zenodo.14918765
D2.2 Numerical modelling and field campaigns to support litter removal at the demo sites