Retention of fish larvae in a fjord system - a seasonal study of the larval life in a West Greenlandic fjord

The Godthåbsfjord is the largest fjord system on the West Greenlandic coast and an important spawning site for several fish species. It houses the largest inshore stock of Atlantic cod (Gadus morhua) on the west coast but also key species like Capelin (Mallotus villosus) and American plaice (Hippoglossoides platessoides) are abundant. The innermost part of the fjord branch Kapisigdlit is the principal spawning site for the fjord population of Atlantic cod, and in 2010 a seasonal study was carried out on the early life of this population. Abundance and distribution of this and other occurring fish larval species was recorded from late March to early August along a 25 km transect covering the length of the fjord branch. Cod spawning started when the upper 20 m of the water column had reached a temperature of 2° C, and cod larvae abundances peaked on June 3rd (16 larvae per 100 m3) in the inner creek. Peak abundances of capelin and American plaice were 4 and 7 weeks later, respectively. Small yolk-sack and post yolk-sack cod larvae were only found on the innermost station. In late July early august larger cod larvae were found on all stations. Larval dispersal apparently was restricted in the early part of the spawning season, while later in the season we found larvae dispersing out through the fjord branch. Considering larval sizes and migratory ability these patterns could be due to seasonal changes in hydrography and tidal flow that may facilitate their dispersal