Trace element ratios in tooth enamel as palaeodietary indicators of seaweed consumption and coastal grazing, and their broader applicability

Ratios of barium and strontium concentrations in skeletal samples (e.g. the logarithmic form lg(Ba/Sr)), are a possible alternative or supplementary marker to stable carbon isotope ratios (δ13C) for identification marine food consumption. Previous studies have compared lg(Ba/Sr) values between different species animals with differing diets, but few been performed where same consumed known diets ranging from completely terrestrial marine. Additionally, how seaweed consumption affects dental bone Ba, Sr other trace element has not yet directly investigated. In this study, tooth enamel modern sheep (n = 15) that containing varying amounts grasses seaweeds were analysed their Sr, Ca, V, Mn, Co, Ni, As, U concentrations. δ13C enable comparison as markers plant The vegetation types (grasses seaweeds) also ratios, soils sands areas pastured. To investigate decay processes (i.e., diagenesis) may affect archaeological enamel, teeth 22 seven sites (ranging ca. 5000 1000 years old) on Orkney Islands, Scotland, analysed. results show seaweed-eating had significantly (−2.4 −1.6) (−6.7‰ −3.3‰) when terrestrial-feeding (lg(Ba/Sr) 0.6 −0.5; −15.5‰ −14.7‰), linear correlation (R2 0.94). Vegetation, soil sand confirmed assumed dependence (bioaccessible) Ba matter. elevated relative U, attributable diagenesis. However, followed trend established using samples, indicating diagenesis did cause significant changes these samples. conclusion, appear be useful indicator amount consumed, including seaweeds. This particularly advantageous locations is unreliable ambiguous an