Sampling was undertaken at 3-h intervals over 24 h on a monthly basis. There was seasonal variation in the density of individuals and biomass with the highest values in summer. A total of 24 species were observed. Species diversity was high throughout the year but equatability was low, due to the dominance of a few species. The largest change in the assemblage structure occurred between March and April. Only a few species could be classified as resident. Most of the species observed were juvenile fish, many with an offshore distribution as adults, using Porto Pim Bay as a nursery ground.