“We are getting more and more alarming signals of dramatic changes in the oceans. The recovery from the changes we’re making will probably take a million years.”

The report found the most affected areas included those responsible for half the world’s fish catch.

A slowing of ocean currents as a result of climate change may over the next 100 years interrupt the transport of nutrients to the most valuable coastal fishing zones, and the flushing away of pollution.

In other impacts, Nellemann said he expected more than 50 percent of coral reefs to die by 2050 as a result of rising temperatures, with resulting impacts on tourism.

Carbon emissions from burning fossil fuels create an acid when dissolved in water, and could over the coming decades make the sea more acidic than at any time in the past 65 million years, and by 2100 could prevent mollusks in some seas from forming shells.