Dispersion and mortality of yolk-sac herring (Clupea harengus L.) larvae from a spawning ground to the west of the Outer Hebrides

A patch of herring larvae located within 24 h of hatching froma spawning bed on the shelf west of the Outer Hebrides, wasfollowed for 7 days. Dispersion of the larvae was modelled usingsimple turbulent diffusion theory. The mortality rate, estimatedfrom the rate of decrease in the total population size, was–2% day^–1 over the tracking period which is verymuch less than rates calculated for herring larvae in otherareas by previous investigators. Successive observations ofthe length, weight, and the incidence of food in the intestinesof larvae, indicated that feeding commenced 5 days after hatchingand that the growth rate was 0.17 mm day^–1.