Fish farming started around 8,000 years ago in China: Study

People in China were engaged in fish farming at least 8,000 years ago –at least 4,500 years earlier than the records exist from Egypt, showed an international study on Monday.

A team of Japanese, Chinese, German and the UK, scouring an early stone age (Neolithic) settlement called Jiahu in the present-day Henan Province in Central China, stumbled upon evidence to show that those who lived there between 6,200-5700 BC were farming common carp, a freshwater fish popularly found in water bodies in Asia and Europe even today. The new findings, published in the journal Nature Ecology & Evolution, pushes the clock back much beyond 1,500 BC, during which Egyptians were believed to have been engaged in farming Nile tilapia fish.

The study assumes importance because the origins of fish farming and domestication are poorly known till date even though aquaculture is the fastest-growing global food production system and it now provides half of all fish consumed by humans. In contrast, there are better records available to show that humans domesticated land animals at least 10,500 years ago.

"There has been a lot of research on domesticated plants and animals, but fish have been poorly understood. This paper shows that humans started to manage fish very early," Mark Hudson of the Max Planck Institute for the Science of Human History at Jena in Germany, who is the co-author of the paper, told BusinessLine. The main author of the study, Tsuneo Nakajima of Lake Biwa Museum in Kusatsu in Japan, however, was not available for comments as he was on yet another field expedition.

The archaeologists discovered multiple number of pharyngeal teeth of carp for three different settlement periods at Jiahu: Period 1 between 7000-6600 BC, Period II between 6600-6200 BC and Period III between 6200-5700 BC.

The researchers measured 588 pharyngeal carp teeth extracted from fish remains in Jiahu corresponding with the three Neolithic periods, and compared the body-length distributions with findings from other sites and a modern sample of carp raised in Matsukawa Village in Japan. While the remains from the first two periods revealed unimodal patterns of body-length distribution peaking at or near carp maturity, the remains of Period III displayed bimodal distribution, with one peak at 350-400 mm corresponding with sexual maturity, and another at 150-200 mm.

"Under the climate similar to the present, carp becomes sexually mature in body-lengths of 300mm. We think that the unimodal distribution suggests fishing of wild carp when they become sexually mature and come to the lakeshore, so that the peak of the graph must be consistent with BL 300mm," said Junzo Uchiyama, a fellow at the Sainsbury Institute for the Study of Japanese Arts and Cultures in Norwich in the UK and another co-author of the study

The bimodal distribution identified by researchers in the study was similar to that documented at the Iron Age Asahi site in Japan (400 BC - AD 100), and is indicative of a managed system of carp aquaculture that until now was unidentified in Neolithic China.

"In such fisheries," the study noted, "a large number of cyprinids (carp) were caught during the spawning season and processed as preserved food. At the same time, some carp were kept alive and released into confined, human regulated waters where they spawned naturally and their offspring grew by feeding on available resources. In autumn, water was drained from the ponds and the fish harvested, with body-length distributions showing two peaks due to the presence of both immature and mature individuals."

The fish belonging to the carp family have been widely exploited by humans since at least 40.000 years ago. While the historical records showed that carp were raised in artificial ponds and paddy fields in East Asia, particularly in China and Japan, by the second millennium BC. But, given that rice paddy fields in China dated back to the fifth millennium BC, scientists believed that carp aquaculture might have also had a similar antiquity. However, there has been no archaeological evidence to support that till date.

"There is already evidence of rice at Jiahu. So far no evidence of rice paddy fields. But the evidence for carp aquaculture suggests that the Neolithic people at Jiahu were able to control water channels to some extent. Therefore rice paddies are not impossible. The technology for rice paddy fields and carp aquaculture may have developed in tandem, " Observed Hudson.