A slew of global leaders met in the south of France to discuss the future of the oceans. There was ‘momentum’ and ‘enthusiasm’, but there were critical voices too

The sea, the great unifier, is man’s only hope … and we are all in the same boat.” So said Jacques Cousteau, the French explorer, oceanographer and pioneering film-maker, who notably pivoted from merely sharing his underwater world to sounding the alarm over its destruction.

Half a century later, David Attenborough, a year shy of his 100th birthday, followed Cousteau’s trajectory. In the naturalist’s acclaimed new film, Ocean, which highlights the destructive fishing practice of bottom trawling, he says he has come to the realisation that the “most important place on Earth is not on land but at sea”.

This message, backed by undeniable indicators of poor ocean health, has boosted calls for more ocean governance and protection. The mood at this week’s UN ocean summit in Nice, which ended on Friday, was that if ever there was a defining “moment” for the ocean, it was happening here, in France’s Côte d’Azur.

But there was also a sense of this sentiment being shared in the wider world, where, partly thanks to the summit, many are finally waking up the reality of the serious decline of something that makes up more than 70% of the Earth’s surface.