Reconstructed annual mean fishing mortality data for 21 important North Sea stocks since 1850 dataset https://portal.medin.org.uk/portal/start.php?tpc=009_CEFAS03a925f9-0009-4e39-bb8f-1f06e617003d Reconstructed annual mean North Sea fishing mortality 1850-2020 for 21 North Sea stocks. Further details can be found in the README file. Sandeel, Norway pout, sandeel, herring, sole, whiting, plaice, haddock, cod, saithe are data-rich stocks with full ICES assessments. Horse mackerel and mackerel have assessments with lower levels of information behind them; poor cod, dab, long rough dab, lemon sole, witch, grey gurnard, starry ray, cuckoo ray, monkfish are data-poor. Fishing mortality is in reciprocal years (yr-1), being the negative log of the fraction of the stock left after one year of fishing at this intensity. So if 1/4 of the stock was fished out in a year, the mortality would be -log(1 - 1/4) or ~0.29. The relation between the annual harvest rate (H - 25% in the above case) and fishing mortality (F) in reciprocal years is given by: F = - log ( 1 - H ) 20250211 20250130