Researchers studying 11,500 - year - former fish bones have discovered the oldest evidence of salmon fishing in North America . allot to their finding , published inProceedings of the National Academy of Sciencesthis week , salmon spawning runs had been established by the destruction of the last Ice Age .
Paleoindians have been traditionally debate big - plot hunters , though their use of fish and other resourcefulness have been difficult to ascertain because of the lack of maintain remains . These day , gazillion of salmon migrate from the sea to breed ( and die ) in their natal rivers and lake . But many of those river used to be blocked by glacial ice , which severely limit salmon ranges . However , there may have been a potential glacial refugium : Beringia , the mostly ice - free land span between Asia and Alaska .
Now , Pisces bone go steady back 11,500 years have been discovered at the Upward Sun River site in interior Alaska around 1,400 kilometers ( 870 mile ) upstream from the coast . The web site is 50 kilometers ( 31 mi ) downstream from the modernistic limit of major spawning areas . base on the show of the vertebrae , research worker conceive that they ’re salmon from the genusOncorhynchus . They recovered 308Oncorhynchusspecimens and the cremate stiff of three - year - old shaver from the central hearth of a residence . A dual babe burial with grave goods were find out 40 centimeters ( 16 inches ) below the fireside . And an additional 29 fragmentize , mostly glow Salmon River specimens were happen within the Inferno fill .
By acquit ancient DNA ( aDNA ) analyses on two of the unburned vertebrae , a team result byCarrin Halffmanfrom the University of Alaska Fairbanks identified the fish aschum salmon(Oncorhynchus keta ) . The team also carry stable isotope analyse on one of the vertebra , and they fix that the salmon had migrated upstream from the sea . Isotope ratios of carbon and nitrogen are typically higher in marine compared with freshwater intellectual nourishment consumers .
The positioning of the cadaver – at the perimeter of modern salmon habitat – suggest that salmon spawning runs were established at least as early as the end of the last Ice Age . These remain also forego any know human uses of salmon in North America – suggesting that salmon may have been a factor in human expansion into the continent ’s northwest region .
Upward Sun River stratigraphy , chronology , and aDNA and stable isotope bone sample . C.M. Halffman et al . , 2015 PNAS
