For centuries, the Pacific Island nations have endured tsunamis, volcanic eruptions, and changing climate patterns that have disrupted the lives of its inhabitants, destabilising entire ecosystems and undermining the intricate food chains that sustain life. 

Today, as temperatures keep rising and weather becomes unpredictable, understanding how past generations adapted their diets to adversity is of paramount importance. 

While building a time machine is not on the cards, Dr Mathieu Leclerc, a biomolecular archaeologist from the ANU College of Arts and Social Sciences, has a way of travelling back in time.

Through his research, he analyses organic residues preserved in pottery for thousands of years –  a technique that allows him to understand what people ate long ago. 

After recently receiving funding from the Australian Research Council, Leclerc will embark on a groundbreaking project in Vanuatu, where he is poised to uncover the evolutionary history of Pacific culinary practices. 

The study of age-old food remnants could illuminate pathways to a more prosperous food future as humans confront an escalating climate crisis. 

The secret life of fat molecules

If you’ve ever washed a sink full of greasy dishes, you’ve probably noticed the presence of stubborn, oily bubbles that cling to the surface and refuse to rinse away. 

These yellowy slicks are made of lipids—a resilient group of organic compounds such as oils and fats that are front and centre to Leclerc’s research.

“Lipids are insoluble in water, which is the reason they are very stable and can be preserved for a long time,” he says. 

“When food is cooked or placed into a pot, fat molecules are absorbed and preserved inside the pottery fabric. 

“Ancient food residues preserved this way can reveal fundamental facts about humanity, such as what people were eating, the types of resources that were cultivated or foraged, and the range of animal species that were available.”

Leclerc specialises in the examination of lipids in archaeological pots, a task that requires meticulous microscopic analysis. 

“Compounds must be first extracted from the pottery. But one of the big challenges is that it is impossible to know if lipids are preserved in pottery until we analyse it,” he says. 

“After extracting the lipids, certain combinations of compounds known as biomarkers allow us to identify certain types of resources and foods. We can also identify these foods by comparing the results with compounds found in modern food and animals. 

“So far in our pilot study we had a high success rate in terms of lipid yield, but it remains uncertain if every sample will behave as nicely.”

History through the cooking pot

The island where Leclerc will conduct his field research, Espiritu Santo, is home to one of the longest documented sequences of pottery use in Oceania. 

This will allow him to investigate the long-term evolution of food practices, spanning 3,000 years. 

“In much of Vanuatu, pottery-making was abandoned a few centuries after people first settled. Today, only a few places still carry on this craft,” he says. 

“Espiritu Santo is one of these rare spots where traditional pottery is still made, although only a handful of expert practitioners now survive in communities of the West Coast of the island.” 

Leclerc is not only poised to uncover the very specific menu Pacific Islanders gorged on, but also the rich cultural and ceremonial layers surrounding their food habits.

“The analysis of organic residues preserved in pottery will provide direct evidence of the circumstances in which specific food items were eaten and of the social value given to foodstuffs,” he says. 

“For example, because pots used for burial ceremonies are different from those used for day-to-day cooking, the residues preserved in both will allow us to identify respectively the food used at funerals, and the food eaten more commonly.

“This might provide information on the social status various food items had, or at least a better understanding of how past people perceived those food items.

“The findings will also provide critical information on understanding the role of pottery in the settlement of the Pacific, an aspect that remains to be investigated using direct evidence.” 

Future proofing the Pacific

As Australia and the Pacific bid to co-host COP31, one message is abundantly clear: the voices of Pacific Islanders must be heard before climate change inflicts irreversible damage on the region’s wellbeing and socioeconomic viability. 

This is particularly concerning in countries like Vanuatu, where a large part of the population thrives on root crops such as sweet potato and yam. 

“The increasing intensity of cyclones, rising temperatures and sea levels, as well as changing rainfall patterns is undoubtedly threatening the sustainability of garden food production,” Leclerc says. 

But what if the solutions we seek today have already been tested, proven, and left behind for us to find? 

“Pacific Island populations before European contact were larger than they are today in many Pacific nations, and were almost wholly sustained through gardening techniques,” he says. 

“Communities in Vanuatu have coped with natural and human-induced hazards for generations. In collaboration with ni-Vanuatu communities, I aim to document the origins and key adaptations of traditional subsistence practices that contributed to food security in the face of ever-changing circumstances.

“These subsistence strategies have historically helped communities build incredible resilience. By learning more about them, the project will add to current discussions on food security and sustainability, while deepening our understanding of human adaptability.”

He envisions his findings informing policies that influence real-world change. Documenting how deep in time traditional cooking practices are found will help to reinforce kastom, a key cultural element of ni-Vanuatu identity, thereby contributing to the nation’s development policies.

“The findings will hopefully help shape smarter, more effective policies to tackle food insecurity, working hand-in-hand with local communities in tropical areas worldwide,” Leclerc says. 

“It’s all about creating practical solutions that build resilience, in line with Australia’s aid strategy to listen to local voices and respond to climate challenges in ways that make a difference.”