74-year-old Teaga Esekia, a chief from the Tuvalu island of Vaitupu. Photo: RNZ / Jamie Tahana

For 74-year-old Teaga Esekia, a chief from the Tuvalu island of Vaitupu, the ocean is lifeblood.

“Tuvaluans, they have different types of months, not like January to December,” said the elderly but agile man, who still climbs coconut trees every day.

“They have their seasons according to fish and planting. We tell the time by fish.”

Mr Esekia was sitting at the edge of the lagoon on Tuvalu’s main island, Funafuti, where he had travelled for a medical appointment. As he sat beneath a tree, sheltering in the breeze from the harsh afternoon sun, he told of how that ocean has changed.

“Some of the common fish, they’re very hard to find now in Tuvalu. That’s a problem we’re facing nowadays.”

The changes seen by Mr Esekia were starkly highlighted last week in the latest report from the Intergovernmental Panel on Climate Change (IPCC).

The report, which was written by more than 100 scientists and experts – including several from New Zealand, Australia, and the Pacific – is based on more than 7000 scientific studies, providing one of the most comprehensive insights into the state of the oceans today.

It concluded that the oceans are heating at such a rate that their chemistry is being altered which, in turn, is threatening seafood supplies, fuelling more extreme cyclones and floods, and posing a profound threat to millions of people who live in low-lying areas.

For the Pacific Islands, it painted a grim picture.