Mortality drives production dynamics of Atlantic cod through 1100 years of commercial fishing

Most edible fish species have been fished for centuries or millennia, leaving little record or understanding of their population responses prior to human impact, and thus no baseline for population conservation. Here, we reconstruct the population dynamics of Atlantic cod, one of the world’s most harvested fish species, from the pristine state during the Viking era through more than 1100 years of fishing. Analysis of cod otoliths recovered during archaeological excavations of Icelandic fish processing sites revealed that cod in the 10th to 12th centuries were 25% larger and up to 300% older than modern, despite slower density-dependent growth rates attributed to the 6-fold increase in abundance. Fishing mortality came to dominate a time-invariant natural mortality rate and other population characteristics after the 14th century, with minimal evidence of environmental effects at the century scale. Despite the absence of catch records and surveys, biological reference points based on pris..., , , # Mortality drives production dynamics of Atlantic cod through 1100 years of commercial fishing

[https://doi.org/10.5061/dryad.9s4mw6msb](https://doi.org/10.5061/dryad.9s4mw6msb)

## Description of the data and file structure

The dataset includes measurements and estimates derived from collections of archaelogical and modern Atlantic cod (Gadus morhua) otoliths from Iceland. Methodological details are provided in the Campana et al Science Advances paper. Three data files are provided:

otoliths archaeological Campana.csv:  Measurements of individual otoliths from the archaeological otoliths

otoliths modern and archaeological for length and age Campana.csv:  Length, age and growth estimates from both the archaeological otoliths and those from a subsample of modern collections from the study area. The archaeological data are the same as those provided in the file otoliths archaeological Campana.csv

cod estimates by century Campana.csv: Century-scale aggregates and estimates of modern ...