Land-based sources of marine




litter and microplastics

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Evaluation and modelling of the




input from rivers and estuaries
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Implementation of prevention and



reduction strategies at the source

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THE PROJECT

Land-based sources of marine litter and microplastics. Evaluation and modelling of the input from rivers and estuaries and implementation of prevention and reduction strategies at the source

This research project lies at the interface among several disciplines, and is aimed at developing knowledge about land-based sources of marine litter, specially plastics and microplastics (MP), a problem of global concern with still many unknowns regarding the nature and extension of its impacts; identify and implement measures for reduction of litter production supported by the relevant stakeholders in the river basin. Therefore, and based on previous work on marine litter by our team, we want to investigate 3 contrasting rivers and estuaries regarding their load of floating plastic litter and MP, relating specific items to their sources and assess their contribution to the sea and the near shoreline, identify hotspots of accumulation and engage the relevant stakeholders to implement reduction and prevention measures in the river basin.

Data from the field campagns will be included in a transport model for the river and estuary and coupled with a coastal drift model to predict transport and target hot-spots from river to sea were accumulated plastic can be removed in quantities that will interest recycling businesses and contribute to circular economy. These models have the capability of backtracking transported items and, validated with field data, constitute a major asset in identifying probable sources of marine litter.

Stakeholders in the watershed producing specific types of litter, will be encouraged to network and build stakeholders platforms, contributing to improve literacy about litter production. These collaborative engagement processes are known to reduce possible conflicts and will make it easier to identify litter elements with the greatest impact. This methodology also improves the building of joint proposals and partnerships to support and implement strategies to reduce the litter produced. These may vary from simple low cost solutions (e.g., covering drains in plastic packaging industrial units to retain pellets) to complex and costly changes in the processes at STP (how to retain plastics from overflows or bypasses), including actions and hands-on activities to promote awareness and co-responsibility among the different sectors of society and the public to reduce at source the amounts of litter entering the oceans.

The overall impacts of the litter reduction measures will be evaluated with a multiple attribute decision making (MADM) tool used to help decision makers, when decisions include several options and when conflicting goals exist. A Handbook of Good Practice for the reduction of marine litter from land based sources will be produced and made available to the public and will stand as a guideline for future actions elsewhere.

THis proposal will contribute to the implementation of descriptor 10 of the Marine Strategy Framework Directive (MSFD) regarding observed tendencies in marine litter, and it is aligned with the european observation network for floating litter in rivers – project RIMMEL.

This Project was funded by the Fundação para a Ciência e Tecnologia, IP through grant reference PTDC/EAM-AMB/30726/2017.

MAIN TASKS

Characterization of litter transported by rivers to the sea

Modeling river litter transport to estuaries and output to the coast and backtracking to sources

Stakeholders Collaborative Engagement (SCE) for Litter reduction

Joint Action Field Work for implementation of mitigation measures

Expected results

  • Baselines:
    1. Quantities and types of litter, specially plastics and microplastics on the margins and carried by rivers and estuaries from watersheds with contrasting land-uses;
    2. Seasonal contribution of river and estuarine plastic litter to the near shoreline under influence of the mouth of the river
    3. Quantification of litter input from the river against regular inputs of marine litter already in the sea
  • Relation of river litter to land-based sources in the watershed

Expected results

  • Prediction of paths for litter transport and accumulation;
  • Identification of land-based sources of litter using backtracking;
  • Identification of hot-spots for litter accumulation to maximize removal from linear to circular economy;

Expected results

  • Building up and consolidate the social, intellectual and political capital in the form of networks and partnerships, emancipatory knowledge, autonomy and capacity building;
  • Increase awareness and co-responsibility among participants involved through the active collaborative development of jointly proposed measures;
  • Encourage the commitment to shared solutions thus strengthening its efficiency.

Expected results

  • Validation and implementation of the selected measures to reduce litter and the level of efficiency of these measures.
  • Assembling of the social, intellectual and political capital from the collaborative process.
  • Producing a Handbook of good pratices to reduce marine litter from land-based sources

MAIN TASKS

Characterization of litter transported by rivers to the sea

Expected results

  • Baselines:
    1. Quantities and types of litter, specially plastics and microplastics on the margins and carried by rivers and estuaries from watersheds with contrasting land-uses;
    2. Seasonal contribution of river and estuarine plastic litter to the near shoreline under influence of the mouth of the river
    3. Quantification of litter input from the river against regular inputs of marine litter already in the sea
  • Relation of river litter to land-based sources in the watershed

Modeling river litter transport to estuaries and output to the coast and backtracking to sources

Expected results

  • Prediction of paths for litter transport and accumulation;
  • Identification of land-based sources of litter using backtracking;
  • Identification of hot-spots for litter accumulation to maximize removal from linear to circular economy;

Stakeholders Collaborative Engagement (SCE) for Litter reduction

Expected results

  • Building up and consolidate the social, intellectual and political capital in the form of networks and partnerships, emancipatory knowledge, autonomy and capacity building;
  • Increase awareness and co-responsibility among participants involved through the active collaborative development of jointly proposed measures;
  • Encourage the commitment to shared solutions thus strengthening its efficiency.

Joint Action Field Work for implementation of mitigation measures

Expected results

  • Validation and implementation of the selected measures to reduce litter and the level of efficiency of these measures.
  • Assembling of the social, intellectual and political capital from the collaborative process.
  • Producing a Handbook of good pratices to reduce marine litter from land-based sources

RESULTS

The distribution of microplastics along the course of the Lis and Mondego rivers, as well as the type of microplastics found have been the RVERSEA object of study in different seasons. The sampling points were chosen considering the location of the plastics production, sale, and recycling industries. Three types of samples were collected: water, sediment and aqueous sediment at the various sampling points selected.

Several types of polymers were found in the Lis River, with PE being the most abundant polymer. The types of polymers found vary throughout the year. The results obtained in the field will contribute to the construction of a hydrodynamic and transport model that provides for the accumulation of marine litter and it will define hot spots that may be interesting in the collection of plastics for recycling, with the plastic being removed from the environment in a contribution to the transition from linear to circular economy.

Transition strategies are being studied and implemented in close collaboration with the project’s stakeholders, who have an awareness and willingness to change.

Publications

Pires A, Sobral P. Application of failure mode and effects analysis to reduce microplastic emissions. Waste Management & Research. March 2021. http://www.doi.org/10.1177/0734242X211003133

PARTNERS