Early Holocene Scandinavian foragers on a journey to affluence: Mesolithic fish exploitation, seasonal abundance and storage investigated through strontium isotope ratios by laser ablation (LA‐MC-ICP‐MS)
Fig 7
Aquatic baseline estimation for ancient Lake Vesan.
Baseline (grey rectangular area) estimated from the interquartile range (25–75 percentile of the data set, using the median value for each tooth), with an added upper variability (the upper whisker representing 1.5 times the interquartile range or, as in this case, the max/min values if they are within this range). Lower variability excluded from baseline estimation. The exclusion of the lower variability is based on the dietary input from terrestrial plants in the water vole diet, which have lowered the water voles 87Sr/86Sr ratio in comparison to ancient Lake Vesan (terrestrial baseline estimated to 0.7172 ±0.008 (1SD). The exclusion of the lower variability in the aquatic baseline estimation is further motivated by the water sampling sources indicating increasing Sr ratios along the tributary system towards the former Lake Vesan (see Fig 6). Estimations based on water vole (WV) data and water samples (WS) collected along the tributary water system that once delivered water to the former lake. Dark blue triangles represent nearby tributary water sampling sources where WS I = Hålabäck, WS III = Vitavatten, WS V = Stora Svartsjön and red triangle represent a remote tributary water sampling source where WS VI = Bredagylet (see Fig 6 for location and S40 Table in S1 File for specific data). Light blue dots represent laser ablations on the water vole teeth with the blue line connecting the ablations from each tooth (data in S33-S39 Tables and S26-S32 Figs in S1 File) and black circle around a blue dot marks the median value of the combined ablations on each tooth.