Ancient Bones Reveal How Rice Farming Replaced the Sea on China’s Coast

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The Jingtoushan site, located on the coast of Zhejiang Province in the Lower Yangtze River Delta, occupies a pivotal position in debates about how early Chinese societies moved from foraging to farming. Dated to roughly 8300 to 7800 years before present, it represents one of the earliest known coastal shell midden sites in the region, and its deposits preserve an unusually rich record of the relationship between people and the sea. Stable isotope analysis of bone collagen, the technique at the heart of the new study, works because the carbon and nitrogen isotopic signatures of human tissues reflect the foods consumed over the years or decades before death. Carbon isotopes distinguish between C3 plants such as rice, which follow a photosynthetic pathway producing relatively depleted carbon values, and C4 plants such as millet, which produce enriched values. Nitrogen isotopes, meanwhile, increase with each step up the food chain, so marine foods, which involve longer food chains, typically yield higher nitrogen values than terrestrial ones. By measuring these ratios in both humans and animals from the same site, researchers can establish local baseline values and then interpret human diets with far greater confidence.

One of the most striking findings at Jingtoushan concerns the dogs. In many archaeological contexts, dogs are effective proxies for human foodways because they tend to eat leftovers, scraps, and deliberately provided meals that mirror what people themselves consumed. At Jingtoushan, the dogs displayed isotope values consistent with a strongly marine-based diet, which indirectly implies that the humans living at the site were themselves heavily reliant on marine resources such as fish, shellfish, and marine mammals. This indirect inference is valuable because human skeletal material from such early coastal contexts is often scarce or poorly preserved, whereas animal remains can be more abundant. The approach therefore allows researchers to reconstruct human dietary patterns even when direct human samples are limited, a methodological advantage that is increasingly recognized in the broader field of isotopic archaeology.

The Lower Yangtze Delta is uniquely important for this kind of research because it sits at the intersection of two major stories in Chinese prehistory: the development of rice agriculture and the long-term adaptation of coastal communities to marine environments. Rice cultivation in this region has deep roots, with evidence of rice exploitation and early cultivation stretching back several millennia before the Jingtoushan occupation. Yet the pace at which rice became the dietary staple, rather than simply one resource among many, has been difficult to establish. Isotopic data provide a direct measure of what people actually ate, rather than what was available or what they might have grown, and thus offer a way to track the real dietary consequences of agricultural intensification.

By combining the new Jingtoushan data with previously published isotopic results from across the region, the researchers were able to trace a broad temporal pattern. During the early Neolithic, coastal populations in the Lower Yangtze Delta drew heavily on marine resources, a pattern consistent with the rich shell middens, fishing gear, and aquatic faunal remains found at sites of this period. As time passed, and particularly through the middle and late Neolithic, the isotopic signatures shifted decisively toward C3 terrestrial resources, reflecting a growing dependence on rice and the terrestrial animals associated with agricultural landscapes. This transition was not instantaneous but unfolded over centuries, mirroring the gradual intensification of rice farming documented by archaeobotanical and other archaeological evidence from the region.

The implications of this dietary shift extend beyond simple subsistence questions. A move from marine-dominated to agriculture-dominated diets would have reshaped nearly every aspect of coastal life. Marine foraging tends to be mobile and opportunistic, tied to tides, seasons, and the movements of fish and shellfish beds. Rice agriculture, by contrast, requires settled occupation, land management, water control, and labor organization, all of which carry social and political consequences. A dietary transition of the kind documented isotopically at Jingtoushan and across the region therefore likely accompanied, and perhaps helped drive, broader changes in settlement patterns, social organization, and even belief systems during the Neolithic.

It is worth noting that the relationship between agriculture and marine resource use is not necessarily one of simple replacement. In many coastal settings worldwide, farming and fishing coexisted for long periods, with marine foods continuing to contribute important protein and nutrients even after crops became central. The isotopic evidence from the Lower Yangtze suggests that while marine resources remained part of the dietary repertoire, their relative importance declined markedly as rice agriculture intensified. Understanding the precise timing and pace of this decline, and whether it varied between sites, communities, or social groups, remains an important avenue for future research. Sites with well-preserved human and animal remains spanning multiple phases of occupation will be particularly valuable for testing and refining the regional pattern identified in this study.

The Jingtoushan findings also contribute to a wider comparative conversation about coastal adaptations globally. In many parts of the world, the transition from foraging to farming in coastal settings has been debated intensely, with some scholars arguing that productive marine environments delayed the adoption of agriculture, and others pointing to cases where farming spread rapidly even among communities with abundant aquatic resources. The Lower Yangtze evidence suggests a middle path: marine adaptation was robust and persistent during the early Neolithic, but it eventually gave way to agricultural dependence as rice cultivation matured. This kind of regional, chronologically controlled isotopic evidence is exactly what is needed to compare trajectories of change across different coastal regions of the world.

Methodologically, the study demonstrates the value of pairing isotopic data from multiple species at the same site. Establishing local faunal baselines is essential for interpreting human isotope values, because isotopic signatures can vary with geology, climate, and food web structure from one location to another. By measuring dogs, pigs, and other animals alongside humans, the researchers could distinguish between genuinely marine diets and terrestrial diets with confidence, rather than relying on generic reference values. This careful baseline approach is increasingly standard in best-practice isotopic studies and strengthens the reliability of the dietary reconstructions presented.

The research also highlights the enduring scientific value of open access publication and data sharing. The availability of supplementary tables containing the isotopic measurements allows other researchers to reanalyze the data, test alternative interpretations, and incorporate the results into broader regional or global syntheses. As isotopic datasets accumulate across East Asia, meta-analyses will become possible that can address questions no single site can answer, such as how quickly agricultural diets spread, whether the transition was uniform across social groups, and how climate fluctuations interacted with subsistence change.

Finally, the study underscores the importance of coastal archaeological sites, which are often threatened by erosion, sea level change, and modern development. Sites like Jingtoushan preserve a unique record of the early relationship between humans and the sea, a relationship that is increasingly relevant today as coastal communities around the world face environmental change. Understanding how Neolithic populations adapted, shifted their economies, and reorganized their societies in response to changing opportunities and pressures offers a deep-time perspective on human resilience and transformation. The isotopic evidence from Jingtoushan, by revealing a clear dietary transition tied to the rise of rice agriculture, adds an important chapter to this ongoing story and demonstrates how modern scientific techniques can illuminate fundamental questions about the human past.

Subject of Research: …

Article Title: Dietary shift from marine to agriculture in coastal Lower Yangtze Delta during Neolithic revealed by isotopic evidence from Jingtoushan

Article References: Deng, C., Sun, G., Wang, Y., & Guo, Y. (2026). Dietary shift from marine to agriculture in coastal Lower Yangtze Delta during Neolithic revealed by isotopic evidence from Jingtoushan. npj Heritage Science. https://doi.org/10.1038/s40494-026-02986-7

Image Credits: AI Generated

DOI: 10.1038/s40494-026-02986-7

Keywords: Neolithic, stable isotopes, Jingtoushan, rice agriculture, Lower Yangtze Delta, marine diet, bone collagen, subsistence transition, coastal archaeology, ancient diets, Dietary, shift