Considerable progress has been made at the international level to address individual categories of coastal and marine pollution, including Persistent Organic Pollutants (POPs) and mercury. And an "international legally binding instrument on plastic pollution" has been negotiated under the aegis of the United Nations Environmental Assembly since 2022. However, there are many other, more diffuse and routine sources of land-based pollution, which receive less attention from the international community. This Note provides a presentation of these main pollutants and their associated impacts on the marine environment, describes and assesses the international initiatives aimed at combating them, and provides some recommendations to strengthen efforts.

IDDRI acknowledges the Oceano Azul Foundation for the initiative to develop this Note and its associated Issue Brief, and for its financial support. These documents are of the full responsibility of the co-authors above identified and their organizations. Their content will be discussed in dedicated meetings and workshops over the coming months, and a final version will be published by the end of 2024.

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Notwithstanding a labyrinth of national, regional and international instruments devoted to the prevention of individual categories of coastal and marine pollution, the overall results, in terms of environmental improvement, are mixed. Some sources of pollution, such as agricultural discharges and urban wastewater, have not been significantly reduced. Moreover, in the absence of a holistic approach, the cumulative impact of pollutants—the “cocktail effect”—is barely addressed by policies: solving one pollution source category does not necessarily mean the marine environment is free from pollution. On a global scale the degradation of coastal and marine ecosystems has therefore continued and in many places has intensified. Yet, high-level declarations on the state of the ocean, as well as some recent intergovernmental agreements, place the issue at the heart of priorities. [...] In 2025, the international community will commemorate the 30th anniversary of the Washington Declaration and the inception of the GPA. This significant milestone coincides with the organization of the 3rd United Nations Ocean Conference, scheduled to convene in Nice (France). This juncture offers a timely opportunity for the global community to initiate a new phase in combating land-based pollution.

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