Civil society, business leaders and policymakers are meeting in Brest for the One Ocean Summit, where issues such as sea levels, plastic pollution, economic development and education will take centre stage. Several initiatives are expected to be unveiled during a meeting hosted by French President Emmanuel Macron, reports Radio France Internationale.
Covering more than 70 percent of the earth's surface, oceans provide not only nourishment but act as regulators in terms of the climate.
The summit, which runs till Saturday, will look at the effects of climate change, conservation, tourism, fishing, pollution and how coastal cities can tackle rising sea levels.
It comes as France settles in to its six-month presidency of the Council of the European Union.
With the support of the United Nations, the event is made up of more than 30 events (workshops, forums, roundtables and other initiatives), bringing together parties interested in the improved governance of the oceans.
Macron will host a small group of heads of State and Government and leaders of multilateral institutions on Friday.
"Facing climate change, the ocean acts as a shield upon which the future of our planet greatly depends," says Françoise Gaill, who's in charge of science with the Ocean and Climate Platform, an organisation hosting one of the forums.
"It is not sufficiently acknowledged that each day, the ocean absorbs a quarter of the CO2 produced by humankind. This is followed by a chemical modification of the sea water which results in the acidification of the ocean.
"Ocean acidity has increased by 30 percent over two and a half centuries and this phenomenon continues to amplify, thus directly threatening marine species."
The World Wide Fund for Nature (WWF) is one of the international organisations hoping to draw attention to its latest report on the impacts of plastic pollution on the oceans, biodiversity and marine ecosystems.
"The problem of plastic is everywhere, from the recesses of the largest oceans, the north and poles, to the most remote islands," the WWF said on Tuesday, referring to data from more than 2,000 separate scientific studies featured in the report.
The organisation estimates that between 19 and 23 million tonnes of plastic ends up in the planet's waterways each year, mostly in the sea.