Figure 3.

Principal component analysis (PCA) for carbon (δ¹³C), nitrogen (δ¹⁵N), non-exchangeable hydrogen (δ²H) and sulphur (δ³⁴S) isotope values, highlighting (a) body size and (b) putative genetically inferred source population assignments of individuals to the Northeast Arctic (NEA) or Iceland populations and (c) north-central or northernmost genomic groups. Values distributed across the PC1–PC2 axes explain 99.18% of the observed variations, while values across the PC2–PC3 axes explain 4.5% of the observed variation. The means (black dots) of each particular body size class (grey cod silhouette) are sorted smallest to largest along PC1s.