Reproduction of Faroe Plateau Cod: Spawning Grounds, Egg Advection and Larval Feeding

Abstract

Faroe Plateau cod spawn mainly in two areas that lie close inside the tidal front that surrounds the Faroe Shelf. Eggs and larvae are advected in an anticyclonic direction around the Islands. Peak spawning is in the second half of March, and, thus, the majority of cod larvae start feeding in April. At this time, secondary production on the central shelf is still at a low level. However, over-wintered Calanus finmarchicus, which are advected from offshore onto the northern and western slope and shelf regions may spawn by April. Observations from April 1995 and 1999 showed that the firstfeeding cod larvae fed mainly on copepod eggs, which, based on their sizes, are presumed to be mainly C. finmarchicus eggs. Copepod nauplii were only of minor importance. The spawning areas of Faroe Plateau cod are close to the areas with the highest average egg productionof C. fmmarchicus during early spring. This results in a coherent advection of cod eggs, larvae, and food from the spawning ground. They are advected clockwise, in an easterly direction, onto the northern shelf region and are then dispersed throughout the central shelf area. As the cod larvae grow, they switch over to larger prey. Food observations in late May 1995showed mainly a mixture of copepod nauplii, young copepodites of C. finmarchicus, and various neritic copepod species (mainly Acartia and Temora), which were produced on the shelf during spring.