PS 50-171 - Are small-scale ecosystem changes from Beothuk inland winter camps captured in Newfoundland lake sediment records?

Background/Question/Methods

Over the last decade, paleolimnological techniques in conjunction with archaeological research have disproven previously foregone conclusions that anthropogenic environmental changes are a modern occurrence and prehistoric hunter-gather communities had a negligible effect on past ecosystems. To expand on this research, I am utilizing sedimentary fecal lipids and charcoal in a multiproxy approach to identify the human presence window at Russell’s Point, Newfoundland, a seasonal Beothuk winter camp used to hunt caribou during their historical migration across Dildo Pond from ~1000 to 1650 A.D. My hypothesis: the fecal lipid proxy will identify the Beothuk presence corresponding with archaeological dating but will expand the human presence window as current dates are dependent on the ¹⁴C preserved in the oldest artifacts/animal bones at Russell’s Point. Sedimentary charcoal will identify small-scale fires from hearths, and may decline after European contact due to fire suppression. Three dated sediment cores, collected downstream of Russell’s Point, have been analyzed for stable isotopes, metal(loid)s, chlorophyll-a, organic carbon, charcoal, and fecal lipids to understand how ancient ecosystems responded to the seasonal presence of prehistoric nomadic humans. These paleolimnological proxies will be compared with archaeological records to provide a multiproxy understanding of environmental responses from Beothuk occupation and hunting practice.

Results/Conclusions

Sediment cores were successfully aligned using sedimentary chlorophyll-a, ²¹⁰Pb-dating, and ¹⁴C-dating to yield long, high resolution sediment records from Dildo Pond. Extrapolated ²¹⁰Pb-dating shows the oldest samples of core 1 reach to the late 1200s, with the radiocarbon dating anticipated to push this time window back further in longer core 3. Metals, normalized to titanium, show an increasing trend between 80 cm and 70 cm for copper, cadmium, chromium, nickel, zinc, and vanadium. These changes correspond with a peak in chlorophyll-a, and may correspond to peak use of the camp by the Beothuk. Long-term trends in stable nitrogen isotopes are highly sporadic suggesting large changes in catchment disturbances, and given the high δ¹⁵N-values, there have likely been marine wastes entering the lake, either from the nearby whaling industry or indirectly from mink farming and its byproducts. Preliminary results capture greater changes in sedimentary proxies in more recent sediments; however, we anticipate that fecal lipids will be sensitive to small population changes from nomadic groups camping on the lake.