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 )