We did not attempt back calculations of fish size as archaeological otoliths are known to be subject to shrinkage and estimates of life fish length based on archaeological otoliths may be underestimated . We therefore used otolith increment measures directly in subsequent statistical analysis. Note that this equates to not consider the biological intercept model , that is, the non-linear relationship between somatic and otolith growth. Both the data and figures presented should be interpreted with this in mind.