ALLOMETRY OF HERRING MORTALITY

I calculated the relationship between instantaneous natural mortality, M (d-1), and dry body weight, W (mug), for herring larvae and adults using data from the scientific literature. Geometric mean mortality of adult Pacific herring Clupea pallasi (0.52-year-1) was about three ti mes greater than that of adult Atlantic herring Clupea harengus (0.18 . year-1), which may reflect greater reproductive effort per unit size by Pacific herring than by Atlantic herring. Geometric mean mortality of Pacific herring larvae (0.083.d-1) was 30% greater than that of At lantic herring larvae (0.064.d-1), but the difference was not signific ant. The functional regression for Atlantic herring was log(e)(M) = -0 .4924 - 0.4064-log(e)(W), and the regression for Pacific herring was l og(e)(M) = 0.1553 - 0.3935.log(e)(W). The regressions provide prelimin ary estimates of average M of herring eggs and juveniles, life history stages for which there are few direct estimates of mortality. They al so indicate that the weight exponent of instantaneous growth of herrin g should be greater than -0.4. Allometry of herring mortality implies that year-class strength of herring should be positively correlated wi th size at recruitment.