The Sea that Gives. The Tide that Takes.

“The sea keeps us alive, but at the same time,
it slowly devours us.”

Grace Maile, Climate Activist from Tuvalu

For generations, the sea has fed the Pacific communities.
Today, the Pacific sits at the frontline of two seemingly unrelated crises: climate change and one of the world’s highest burdens of obesity, diabetes and heart disease. But could one be fuelling the other?

As you scroll: hover or tap highlighted words for quick definitions, use the buttons to switch what is shown on charts and drag sliders to explore future scenarios.

The NCD Capital of the World

The Pacific Islands have been widely described as the non-communicable disease (NCD) capital of the world,¹ with around 75% of all deaths in the region being attributed to NCDs.²

Globally, the Pacific Islands accounted for:

The top 10 countries by obesity prevalence in 2024³
6 of the top 10 countries by deaths due to cardiovascular disease (age-standardised) in 2021⁴
The top 10 countries by diabetes prevalence in 2014 (measured as raised fasting blood glucose; age-standardised)⁵

Obesity (2024) Cardiovascular disease (2021) Diabetes (2014)

Pacific islands and territories Rest of world

Raised fasting glucose defined as >=7.0 mmol/L. Datasets: World Health Organization Global Health Observatory, with processing by Our World in Data.³^,⁴^,⁵

The Nutrition Transition

The primary driver of the Pacific NCD epidemic is an ongoing nutrition transition from locally grown whole goods to imported staples and highly processed foods.⁶

For generations, Pacific communities didn’t need a supermarket. The sea, reef and garden were the food system: fresh fish, taro, breadfruit, coconut and locally grown crops made up the bulk of the diet, supplemented by pigs and chickens raised close to home.⁷

The sea doesn’t just surround the islands. It feeds them. Fish, in particular, has long supplied the majority of the region’s animal protein, accounting for 38.7% of total animal protein intake, more than double the world average of 16.1% (data circa early 2000s).⁸

However, there has been a transition towards imported, often highly processed foods such as white rice, flour, instant noodles, canned foods, fatty low-grade meats and high-sugar soft drinks.⁷ Fish remains a staple, but several studies have shown a decline in fresh fish consumption, particularly in urban populations.⁹ Increasing dominance of imported foods has been identified a key driver of the NCD epidemic.⁶

This shift can clearly be seen in the net import/export from the region, which has crossed the line from net export in 1995 to net import in 2022.¹⁰

To reverse this trend and increase the reliance on traditional, healthier food sources will need robust local food production. But the nutrition the sea provides is at risk…

A woven basket holding a fish, a coconut, a breadfruit and a root vegetable

The same basket now filled entirely with fish

The same basket now holding a packet of instant noodles, a tin, a bottle of sauce, a packaged loaf, and a bottle of soft drink

Net import/export to and from the Pacific Islands and Territories calculated using inclusion/exclusion criteria used by Brewer et al.¹⁰ Dataset: Pacific Data Hub, Pacific Food and Beverage Trade - The Pacific Food Trade Database.¹¹

The Changing Ocean

Sea levels are rising.

Sea temperatures are rising.

Today, the ocean is changing.

This can be seen in clear increases in sea surface temperature and sea level anomalies.

Pacific region sea surface temperature anomalies

1850–2025, relative to 1971–2000 baseline

Annual mean anomaly is the average mean monthly sea surface temperature for each exclusive economic zone, relative to the baseline period 1971–2000. The regional figure is the unweighted mean of all 21 Pacific Island countries and territories in the dataset, so each is given equal weight regardless of ocean area; source values are reported to 0.1 °C. All 21 territories warmed between 1900–1929 and 2016–2025. Dataset: SPC Pacific Data Hub, Climate Change Indicators - sea surface temperature anomaly.¹²

Pacific region sea level anomalies

1993–2023, relative to 1993–2012 baseline

Sea level anomaly is defined as the difference between observed sea surface height and the 1993–2012 long-term reference baseline, expressed in metres. The regional figure is the unweighted mean of all 21 Pacific Island countries and territories in the dataset, so each is given equal weight regardless of ocean area; source values are reported to 0.1 m, so the regional mean is more precise than any single territory’s figure. All 21 territories rose between 1993–1997 and 2019–2023. Dataset: SPC Pacific Data Hub, Climate Change Indicators - sea level.¹³

The effects on the land are already being seen.

On Kwajalein in the Marshall Islands, flood days have already climbed from around 20 a year in the 1980s to 60–80 a year in the 2020s.¹⁴

High tide flooding frequency

Kwajalein, Marshall Islands, 1975–present · darker bars = more flood days

Source: NOAA National Ocean Service, Center for Operational Oceanographic Products and Services (CO-OPS). High Tide Flooding Annual Flood Count, Station ID 1820000, Kwajalein, Marshall Islands.¹⁴ All flooding shown here is classed as ‘minor’ severity; moderate and major flooding remain rare so far.

Long before shorelines disappear, saltwater seeps into gardens, crops and freshwater supplies, slowly eroding natural food sources that Pacific communities rely on.

And these trends show no signs of slowing down in the future!

The Tide that Takes: What the Future May Bring

Projections for the future are highly dependent on global actions to limit the magnitude of climate change.

Sea level rises have been modelled for Tuvalu.¹⁵ Tuvalu is one of the lowest-lying nations in the world, with a highest elevation of only 4.5 metres above sea level, so highly vulnerable to sea level rises.¹⁶

Even the best case brings measurable sea level rise by 2100; the worst case brings nearly a metre.

Tuvalu sea level rise

From best case to worst case, 2020–2100

Source: NASA Sea Level Change Team (2023). Assessment of Sea Level Rise and Associated Impacts for Tuvalu. Technical Report N-SLCT-2023-01, Table 2.¹⁵ Lines connect three modelled anchor points (2020, 2050, 2100), not a smoothed projection. Shaded bands show the 17th–83rd percentile ‘likely range’ per IPCC AR6 methodology, not a minimum/maximum or worst-case bound.

Rising sea levels have the potential to swallow land masses.

But the tide takes more than land.

Something else happens beneath the surface.

The fish change and move.¹⁷

As ocean temperatures rise, tuna populations are expected to shift eastwards for cooler waters.¹⁷ Tuna catch projections have been performed based on purse-seine fishing, the dominant method of commercial tuna fishing in the region.¹⁸

Under a lower-emissions pathway, catches in the EEZ of ten tuna-dependent Pacific small-island nations are projected to fall by only around 3% by 2050. But under a high-emissions pathway, that decline reaches an average of 20%.

Projected purse-seine tuna catch, by 2050

Tonnes per year from the EEZs of the ten tuna-dependent Pacific SIDS. Outlines show the 2009-2018 average.

Source: Bell et al. (2021) Nature Sustainability, Table 1 (CC BY 4.0).¹⁸ RCP 2.6, closest to the Paris Agreement, was judged too uncertain by the authors to report.

As well as the impact this would have on the economies of these nations, this trend may be indicative of the availability of tuna to the islanders themselves.

Without locally caught fish, it is all too easy for imported food to fill the gap.

A Tale of Two Crises: The Double Burden

The changes in fish stocks will not affect every Pacific nation equally. Some countries rely more heavily on marine fisheries for food, livelihoods and economic activity than others.

The marine fisheries vulnerability index scores 147 coastal countries on how badly climate change is likely to affect their fisheries by combining projected ocean warming, their dependence on fisheries, and adaptive capacity (scale of 0 to 1, with 1 being the most vulnerable).¹⁹

Looking at the climate vulnerability of marine fisheries alongside the prevalence of NCDs, we can see that some nations face a double burden.

Circle area: fisheries vulnerability (fixed)

0.4 0.7 1.0

Circle colour: world ranking on the measure selected above

World top 10 11 to 25 26 to 50 51 to 100 Outside top 100

Dataset: Blasiak et al. (2017). PLOS ONE.¹⁹ Marine vulnerability index is shown for a high emissions scenario (RCP 8.5) over 2016 to 2050.

Nine Pacific island nations are included in the ranking.

Projecting for a high emissions scenario from 2016 to 2050, six of those nations fall into the top ten in the world: Kiribati ranks first, ahead of the Federated States of Micronesia and Solomon Islands, with Vanuatu, Samoa and Tuvalu also inside the top ten.

Four of those six also ranked among the top 25 countries by obesity levels in 2024; four in the top 25 by deaths due to cardiovascular disease in 2021; and all six in the top 25 by diabetes prevalence in 2014 .

This reveals an uncomfortable overlap: many of the nations that are most vulnerable to changes in fisheries are also among those already facing some of the world’s highest burdens of NCDs.

Conclusion

Climate change may not have created the Pacific’s NCD crisis, but it could make it harder to solve.

As the ocean changes, so too may the foods that reach the dinner table.

Action plans are in place to tackle the NCD crisis,²⁰^,²¹^,²² but protecting the health of future generations will depend not only on local actions, but on the choices the whole world makes today.