Bloomberg Philanthropies announced the commitment June 23 at the Earthshot Prize Impact Assembly during London Climate Action Week, that it targets the High Seas Treaty, the agreement that for the first time allows protected zones in international waters, which cover nearly half the planet's surface.

Governments have promised to protect 30% of the oceans by 2030. With four years left, about 10% is protected.

Bloomberg is worth about $109 billion, according to Forbes, ranking him among the 20 wealthiest people in the world. Much of that fortune comes from the company's Bloomberg Terminal, the trading-floor data service whose subscriptions run about $32,000 a year.

Bloomberg Philanthropies says the pledged money will help identify, establish and police the first marine reserves under the treaty. The pledge takes its total ocean spending to $635 million.

"The High Seas Treaty shows that the world has the will to protect the ocean," Bloomberg, who built his fortune through the financial-data company Bloomberg LP, told Sky News. "This investment will help ensure we have the way."