A new study by the Australian National University (ANU) has revealed new insights into ancient fishing throughout history, including what kind of fish it regularly fed as part of a diet.
The study focused on the fish bones discovered in the archaeological excavation on the Indonesian island of Alor, home to the oldest fishing hooks in the world that have ever appeared in the human burial ground for about 12,000 years.
Chief Archeologist Dr. Sofia Samper Carro of the ANU School of Archeology and Anthropology said in the study identified a shift in angler's behavior some 7,000 years ago.
"People in Alor hunted open water about 20,000 years ago, then about 7,000 years ago they began to hunt exclusively for reef species," she said.
Dr. Samper Carro said a similar pattern was found on the nearby island of Timor, suggesting that the change in behavior was due to surrounding circumstances.
"It seems to have been caused by changes in sea level and surrounding conditions, although man-made change can not be ruled out," she said.
The results were made possible by the method of analysis traditionally used in biology to identify the fish environment in archaeological material. Dr. Samper Carro said she was forced to experiment with a new approach because of the difficulty of determining the difference between very similar looking bones of 2,000 known fish species.
"This study is the first time the researchers have been able to reliably determine the fish habitat using the vertebrate method and represent a significant step forward in monitoring human behavior throughout history, Samper Carro.
"Most of the bones you find in archaeological sites are vertebrae, which are very complicated in identifying species and all look very similar.
"If we do not know the species, we do not know their habitat.
"In Indonesia you have more than 2,000 species of fish so you can know which bones belong to which species you will need 2,000 species of fish in your comparative collection.
"I spent about five months trying to compare each fish vertebrate with another, and I think I got 100 out of 9,000 bones, so I needed to find another method."
Dr. Samper Carro instead turned to geometric morphometry, a process that deals with small differences in the size and shape of physical objects. Using over 20,000 digital images and rendering 31 points on each bone, it was able to digitally identify the likely biotope from each vertebra.
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