NURSERY GROUNDS OF DAB (LIMANDA-LIMANDA L) IN THE SOUTHERN NORTH-SEA

The distribution of 0-group dab, Limanda limanda L., in the open North Sea, the Dutch coastal zone and the estuarine Wadden Sea was investigated and patterns of seasonal abundance and growth were compared. The purpose was to locate the nursery grounds of dab and to assess their relative importance. Settlement was observed in the North Sea, both in coastal and offshore waters. Highest densities of 0-group dab were found in coastal areas. Since the coastal zone covers only a relatively small part of the North Sea it is not necessarily the most important nursery area for dab. No settlement of dab occurred in the Wadden Sea. Large numbers of juveniles were caught in the tidal channels and subtidal areas in autumn, but their size range indicated that migration rather than settlement was responsible for the observed increase in numbers. A similar process of inshore migration occurred in shallow coastal waters in October. Growth of 0-group dab was more or less similar in all areas. Mean length increased to 6-7 cm by the end of the first year of life.