The teeth of the gilthead seabream revealed the secret: ancient aquaculture took place in our region as long as 3,500 years ago. This finding emerges from a new study undertaken by the University of Haifa, Oranim Academic College, Israel Oceanographic and Limnological Research, and German researchers from the Universities of Mainz and Göttingen. According to the study, which was published in the prestigious journal Nature Scientific Reports, aquaculture was pursued in the Mediterranean Sea, constituting the earliest empirical evidence today anywhere in the world. “According to the new findings, together with archeological findings from the Late Bronze and Iron Age (the Biblical period), we find that Egypt became a superpower in aquaculture, exporting fish to the north – including to the Israelite and Canaanite cities,” explains Dr. Guy Bar-Oz of the University of Haifa, one of the authors of the study.
Aquaculture is developing rapidly today due to growing demand for the consumption of fish, leading to what has been dubbed the “blue revolution.” But when did humans first begin to develop organized aquaculture? Wall paintings from ancient Egypt, dating back to the third century BCE, include depictions of fishing and the cutting of fish for marketing. But until now we had no archeological or empirical evidence of aquaculture from such an early period. In the present study, which was funded by the European Research Council (ERC), the German Research Council (DFG), and the Israel Science Foundation (ISF), the researchers found early empirical evidence predating the wall paintings by several centuries. The study was led by Dr. Guy Sisma-Ventura of Israel Oceanographic and Limnological Research, together with Prof. Guy Bar-Oz, Prof. Omri Lernau, and Prof. Ayelet Gilboa of the Zinman Institute of Archaeology at the University of Haifa; Prof. Dorit Sivan of the Department of Maritime Civilizations at the University of Haifa; Dr. Irit Zohar of Oranim Academic College and the Zinman Institute of Archaeology at the University of Haifa; Prof. Andreas Pack of the University of Göttingen; and Prof. Thomas Tütken of the University of Mainz.
The study was based on an examination of the oxygen isotopes in the teeth of gilthead seabream, which reveals where the fish were raised during the first few months of their life, when their teeth were formed. “The ratio of oxygen-18 and oxygen-16 isotopes varies in nature according to a fixed pattern reflecting the temperature of salinity of the water. Accordingly, examining the ratio between these isotopes in teeth of modern and ancient fish allow us to identify and calculate the water temperature and salinity in which the teeth were created. Once we have these data, we can cross-reference them with other geological, archeological, and historical evidence regarding the temperature and salinity of seawater in various areas, thereby identifying the possible habitat in which the fish was raised and the period in which it lived,” Dr. Sisma-Ventura explains.
The current study samples over 100 teeth from gilthead seabream gathered from various archeological sites in Israel, including coastal sites such as Dor and Ashkelon, as well as inland sites such as Jerusalem and Hazor. The sample of teeth covered a chronological period extending over 10,000 years, from the early Neolithic period (the beginning of the Agricultural Revolution) through to the early Islamic period (the 7th-8th centuries CE).
The findings showed that in ancient periods some 3,500 years ago, gilthead seabream were caught in two main areas: in the open sea and in ancient saline coastal lagoons. However, some 4,000 years ago, as sea levels stabilized, a dramatic change occurred and most of the fish was caught in a single habitat: the saline lagoon at Sabhat Bardawil in Northern Sinai. “The examination of the ratio between the isotopes indicated the temperature and salinity levels at which the fish were raised from this period. When we examined all the possible sites, we found that only the saline lagoon at Bardawil matched this specific chemical profile,” the researchers explained.
The study also found that during the Biblical periods, the gilthead seabream was the main fish imported to sites in the center of Israel. The size of the fish was also consistent with the transition to aquaculture. In periods 3,500 years ago, the fish caught showed a wide variety of sizes, small and large, but from this point forward, the range of sizes narrowed. By the Biblical period, the imported fish were all “plate sized” – “around 500 grams and 40 cm long, just as we see in fish raised by modern aquaculture,” Dr. Zohar noted.
The new findings, together with additional archeological evidence from the Late Bronze and Iron Ages, reveal a pattern of aquaculture and commercial ties between Egypt – the mighty empire to the south – and the ancient settlements.
Publication in Nature Scientific Reports,