The Ação Lixo Marinho (ALIMAR) project aims to promote a greater awareness of the general public and school, about the problem and impact of garbage in the Ocean, in particular plastic, through citizen science actions and environmental civicism. Through the establishment of a National Network for the monitoring and collection of marine litter, as well as the implementation of citizen science actions, educational activities and community involvement, the intention is to raise awareness of the conservation of the marine environment and encourage responsible consumption habits. Main objectives include: (1) Increased awareness of the marine litter problem; (2) Active citizenship and mobilisation to reduce marine litter on our coastline; (3) The reduction in the use of disposable and single-use plastics; (4) Citizen science actions in situ on the presence of marine litter on our beaches; (5) Stimulating the transition to a circular economy with regard to the use of plastic, especially in fishing activity.