The egg production and spawning stock size of the North Sea mackerel and horse mackerel stocks in 1988

摘要

During the period 5 April to 28 July 1988 the spawning areas of North Seamackerel and horse mackerel were investigated by research vessels from theNetherlands, Denmark and Norway. Based on the plankton samples andtemperature observations obtained during this period the egg productionand spawning stock size were estimated. The total egg production ofmackerel represents a spawning stock biomass of 37 000tonnes, which is about 20 % less than the 1986 estimate. The total eggproduction of horse mackerel represents a spawning stocksize of 110 000 tonnes.