There is pressure on the UN Ocean Conference starting Monday in Nice to show that countries can unite and deliver more than just talk for the world's ailing and neglected seas.

- Plundered parks -

Several countries are expected to announce the creation of new marine conservation zones within their national waters, though how protected they really are will come under scrutiny.

Some countries impose next to no rules on what is forbidden or permitted in marine zones. France and other EU states, for example, allow bottom trawling, a damaging fishing practice, in protected waters.

This means just three percent of oceans are considered truly safe from exploitation, far short of a global target to place 30 percent under conservation by 2030.

- High seas -

Key to achieving this goal is enacting the high seas treaty, a landmark global pact signed in 2023 to protect marine life in the vast open waters beyond national control.

France had pinned success at Nice on delivering the 60 ratifications necessary to bring the treaty into force, saying the conference would be a failure without it.

But it could not get the required number, drumming up roughly half ahead of the summit. Those outstanding will be pushed to explain when they intend to do so.

- Uncharted waters -

France will be leading diplomatic efforts in Nice to rope more countries into supporting a moratorium on deep-sea mining, a contentious practice opposed by 33 nations so far.

Bolstering those numbers would send a rebuke to US President Donald Trump, who wants to allow seabed mining in international waters despite concerns over how little is understood about life at these depths.

But it would also carry weight ahead of a closely watched meeting in July of the International Seabed Authority, which is haggling over global rules to govern the nascent deep-sea mining sector.

- Actions not words -

At the summit's close, nations will adopt a pre-agreed political statement that recognises the crisis facing oceans, and the global need to better protect them.

Critics slammed the language in the eight-page document as weak or -- in the case of fossil fuels -- missing altogether, but others cautioned against reading into it too much.

"The end declaration from here isn't really the only output. It's much more important, actually, what governments commit to, and what they come here to say on an individual basis," said Peter Haugan, policy director at the Institute of Marine Research in Norway.

- Money matters -

The conference is not a COP summit or a UN treaty negotiation, and any decisions made between June 9 and 13 in Nice are voluntary and not legally binding.

But countries will still be expected to put money on the table in Nice to plug a massive shortfall in funding for ocean conservation, said Pauli Merriman at WWF International.

"What we lack -- what we still lack -- is the ambition, the financing and the delivery needed to close the gap," she told reporters.

"It's not enough for governments to show up to Nice with good intentions."