Spatial and temporal differences in fecundity of Atlantic herring (<i>Clupea harengus</i>) off Nova Scotia and consequences for biological reference points

The relationships between fecundity and size of Atlantic herring (Clupea harengus) were estimated within five different spawning areas off the coast Nova Scotia in 2019 2020. Statistically significant differences relative to body weight observed among years. Fecundity-at-length on German Bank ground was 29%–36% 22%–28% lower than estimates from 2001 1970, respectively. Temporal changes weight- fecundity-at-age resulted a decrease number eggs-per-recruit (in an equilibrium unfished state) by 50% 27% egg production per tonne stock biomass (SSB) 2020 1970. Decreases SSB-per-recruit over time proportional decreases SSB at maximum sustainable yield (MSY); however, fishing mortality rate (F) MSY remained relatively stable time. Total shown be disproportional SSB. Equilibrium greater (and F lower) when using compared SSB-per-recruit. Failing account for assuming that is overestimate status.