Comparison of growth rates between estuarine and coastal reef populations of Achoerodus viridis (Pisces: Labridae)

Abstract

Patterns of abundance and size-frequency distributions of Achoerodus viridis (Pisces: Labridae) in the Sydney region (New South Wales, Australia) showed greater numbers of small fish (<200 mm standard length, SL) on estuarine reefs than on open coastal reefs. In contrast, open coastal reefs had greater densities of large fish (>200 mm SL). Growth of A. viridis was therefore investigated to determine to what extent differences in size-frequency distributions between estuarine and open coastal reefs could be explained by slower growth at estuarine reefs compared to open coastal reefs. No significant differences in growth of A. viridis were found between estuarine and coastal reef sites. Spatial differences in size-frequency distributions are most likely due to movement of fish from estuarine to coastal reefs, rather than differences in growth of fish.