A method for identifying salmon remains using mineral markers developed at the University of Haifa sheds light on the Late Stone Age in the Arctic Circle, according to a new study published in the academic journal Scientific Reports.While archaeological researchers have assumed that salmon would have been crucial to the early diet of the ancient Arctic’s inhabitants, there has been little proof until now.“The new method we have developed will enable researchers to better understand life in the ancient Arctic and the way in which seamstresses are able to move to permanent communities,” said Prof. Ruth Gross, who led the study, in a statement.While evidence has been previously found that indicated inhabitants of the ancient Arctic Circle would catch fish, and particularly salmon, few fish bones were ever discovered in archaeological research, according to Dr. Don Butler of the Department of Marine Civilizations at the Leon Charney School of Marine Sciences at the University of Haifa. Butler is a postdoctoral researcher who co-authored the study.Gross added that the importance of salmon today in Scandinavia, together with the paucity of bones, has made the subject significant for local researchers and archaeologists.Gross and Butler developed a method, along with Vlad Brumfeld from the electron microscopy unit of the Weizmann Institute of Science in Rehovot, to show that salmon bones burned in bonfires would create minerals consisting of whitlockite and beta magnesium tricalcium phosphate that were specific to salmon. Thus while the bones themselves were not located, their mineral residue was preserved for thousands of years. Gross and Butler worked with Dr. Sato Koivisto of the University of Helsinki, who provided the Israeli team with the Mid-Holocene period salmon bones found in excavations in Finland over the years. The mineral marker that Gross and Butler discovered matched that of the fish.The researchers then turned to one of the oldest settlements on the Iijoki River in northern Finland, where they sampled ash from a fire found in a 5,600-year-old cabin. Laboratory results showed that the salmon’s signature mineral marker could be found within the ash.This, combined with the team’s sieving efforts and mineralogical analyses of these sediments, along with zooarchaeological identification of recovered bone fragments, confirmed that salmon was part of the diet of people living in the village. The findings provided new evidence for early estuary or riverine fisheries in northern Finland’s Lapland region.The method developed at the University of Haifa will enable archaeologists in the future who are working in the ancient Arctic periods to collect evidence of salmon consumption, and perhaps other relationships salmon may have had with Arctic river ecosystems.