New UHI archaeology paper examines the origins of aquaculture

The University of the Highlands and Islands Archaeology Institute is pleased to announce the publication of an important research paper in the Nature Ecology and Evolution journal.

The paper, by Dr Jen Harland, lecturer in archaeology at the UHI Archaeology Institute, examines the wider implications of the work published by Nakajima (2019) comparing the size of ancient and modern carp. The paper concludes that the initial stages of aquaculture began around 6000BC, perhaps three thousand years earlier than was previously thought.

Utilising the three stage model of fish domestication proposed by Nakajima (2019),Dr Harland reiterates that the process of domesticating common carp commenced with the use of wild species in managed ponds and ditches within two areas in the world – an eastern population in China, Laos and Vietnam and a Western population in the Black Sea, Aral Sea and Caspian Sea areas.

Full domestication commenced in Asia when carp fish farming was combined with a rice paddy cultivation producing a symbiotic relationship in which the fish naturally ate weed plant species and insect pests while providing natural fertilizer.

Examining archaeological specimens from the Chinese Neolithic site of Jiahu, and comparing these measurements to modern carp raised in a traditional Japanese rice and fish co-culture, Nakajima and co-authors were able to establish that carp were being managed at Jiahu by 6000BC – much earlier than previously thought.

Dr Harland goes on to emphasise the point that the final stage of domestication can be recognised only when breeding, diet and habitat are all controlled by people. Previous studies have shown that the start of aquaculture in Europe was signalled by the management of carp in controlled ponds during the Roman period in the Danube region.

Carp then became truly domesticated in Europe in the 12-14th centuries AD. Various authors have questioned whether the domestication of carp took place in Asia or in Europe, and whether or not the domesticated animal was then moved from one region to another.

Given the evidence for the early origin of fish farming reported in Nakajima’s study, Dr Harland states that is is likely that common carp was domesticated independently twice, once in Asia and separately in Europe.

Dr Harland said: “It was a real honour to be invited to write this news and views piece discussing the wider context of Nakajima’s study on the origins of carp aquaculture.

“As archaeologists we discuss the advent and spread of farming and domestication in the context of cattle, sheep and pigs, but the domestication of fish is often overlooked. Farmed fish are of huge importance to our diets today, but these intensive methods are very controversial. By using archaeological methods to examine the origins of aquaculture, it’s now apparent that these carp were raised in a sustainable and balanced system alongside rice cultivation for a very long time indeed.”

According to Dr Harland, modern aquaculture will soon produce half of the world’s fish supply, but intensive methods are resulting in environmental degradation, loss of biodiversity and non-native species invasions.

This paper emphasises that adopting a long established fish-rice co-culture system would continue a long tradition of sustainable farming which largely avoids the pitfalls of modern intensive mono culture fish farming – showing that we have much to learn from traditional methods of agriculture and aquaculture.