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.