DISTRIBUTION AND ABUNDANCE OF SOLE (SOLEA-SOLEA (L)) EGGS AND LARVAE IN THE BAY OF BISCAY BETWEEN 1986 AND 1989

The principal spawning period of sole in the northern part of the Bay of Biscay is from late February to late March. Larvae are abundant in late April. Four annual surveys revealed a great stability of both spatial and temporal distribution of the pelagic stages. The peak density of eggs frequently occurred in a well-defined limited area in the middle of a zone with sandy sediments. The pattern of the dome-shaped distribution was conserved during the larval development (30 to 40 days after fertilization). The mean temperature observed in 1986 and 1987 over the spawning area was about two degrees lower than in 1988 and 1989. Despite this difference, the time of spawning as well as egg and larval abundance appeared stable. The year-to-year differences in egg and larval abundance did not exceed a factor of two. These observations suggest a low variability in the year class strength unless an increase in abundance variability occurs during settlement and juvenile stages.