Portugal ratified the Convention for the Protection of the Marine Environment of the North-East Atlantic, OSPAR Convention, in 1997, and participated in the Pilot Project for Monitoring of Marine Litter in the coastal zone which took place between 2000 and 2004.

The Convention for the Protection of the Marine Environment of the North-East Atlantic (the OSPAR Convention) is a mechanism by which 15 European entities cooperate to protect the marine environment of the North-East Atlantic.

The Contracting Parties to the OSPAR Convention are: Germany, Belgium, Denmark, Spain, Finland, France, Holland, Ireland, Iceland, Luxembourg, Norway, Portugal, United Kingdom, Sweden, Switzerland and the European Union.

The area covered by the OSPAR Convention comprises five regions: Region I - Arctic; Region II - North Sea Region III - Celtic Seas; Region IV - Bay of Biscay and the Iberian Coast and the Region V - Vast Atlantic. Continental Portugal is integrated into the Region IV and the Azores in the Region V.

Portugal ratified the OSPAR Convention by Decree-Law nº. 59/97 of 31 October. Currently, the national representation is ensured by the Directorate General of Natural Resources, Security and Maritime Services.

The Contracting Parties, in accordance with the provisions of the Convention, shall undertake to take all possible measures to prevent and eliminate pollution and shall take the necessary measures to protect the maritime area against the adverse effects of human activities so as to safeguard human health and to preserve ecosystems and, when practicable, restore marine areas which have been damaged. For this purpose, the Contracting Parties shall, individually and jointly, adopt programs and measures and harmonize their policies and strategies.

In 1999 the OSPAR Commission endorsed a proposal from one of its working groups for the implementation of a Pilot Project for Monitoring of Marine Litter on beaches. Portugal, through the Reference Laboratory of Environment, participated in this pilot project. For the implementation of this pilot project was selected the following beaches Barra (Aveiro), Carcavelos, Duquesa (Cascais), Meia Praia, Batata, Camilo, D. Ana (Lagos). Between 2001 and 2003 held several campaigns for identification and collection of materials on the beaches. In 2004 were also included the beaches: Cabedelo (Viana do Castelo) and Manta Rota. The result of these campaigns is compiled in the report of the Pilot Project of Marine Litter on beaches.

On the basis of this pilot study and in its conclusions, the OSPAR Convention has developed a guide for monitoring marine litter on beaches. This guide is intended to be a tool for obtaining data on marine litter according to a standardized methodology. The monitoring carried out in a uniform manner and harmonized enables an inter-regional interpretation of the situation of marine litter and comparison between regions. In 2010, the OSPAR Commission adopted "guidelines" for monitoring marine litter on beaches resulting from the pilot project:

The APA has resumed the monitoring of marine litter on beaches, in January 2013, for this purpose set out a Program for the Monitoring of Marine Litter on beaches along the national coastal zone that contemplated until 2016 nine beaches having been included in 2017 two more.

In 2013 the OSPAR Commission agreed to develop by 2014 a Regional Action Plan for the Marine Litter Being the sources of marine litter and by the fact that the dynamics of the oceanic transform a transboundary issue there is no doubt that only a collective action will solve the problem. So the OSPAR Convention examined the feasibility of developing a Regional Action Plan for the implementation of the commitments of the Strategy for the Environment in the Northeast Atlantic as well as coordinate actions that will achieve the Good Environmental Status for the descriptors of MSFD also contributing to the United Nations Environment Program and for the Global Partnership on Marine Litter.

This regional plan of actions is a flexible tool that comprises 84 shares distributed by 4 themes (A - combating the sources of marine litter at sea; B - Combating marine litter on earth; C - Removal of marine litter and D - Education and Dissemination) to address the problem of marine litter. Includes actions that require collective activities in the framework of the Conventions and others that may be included in national programs of measures even in the context of MSFD, there are still others whose competence falls within the field of international organizations and authorities. Portugal participates through the DGRM in several actions being a leader in action 49 which investigates the prevalence and impact of expanded polystirene (polystirene (EPS)) in the marine environment, and collaboration with industry to the development of proposals for alternative materials.

In the strategy to be followed between 2010-2020, the OSPAR Commission for the protection of the marine environment of the North-East Atlantic, the question of marine litter is addressed in conjunction with the strategies for biodiversity and for the dangerous substances. It is manifested the intention, moreover in line with the concept associated with Good Environmental Status, to substantially reduce marine litter in the OSPAR maritime area to levels at which the characteristics and quantities of marine litter do not adversely affect the coastal and marine environments.