Spatial and interannual patterns in growth of an exploited coral-reef fish

Abstract

Patterns of growth in an exploited reef fish Lethrinus miniatus were examined over 5 years (1995–1999) at two spatial scales: (1) among regions of the Great Barrier Reef (GBR) separated by >100 km and (2) among reefs within each of these regions, separated by ≤10 km. Mean annual growth of L. miniatus varied significantly among years, but this variation was consistent among ages and regions, indicating that factors that influence temporal patterns in growth were not age-specific and operated at relatively large spatial scales. Significant variation in growth was also observed among some reefs within regions, although the greatest variation was among regions. The average maximum fork length (LF∞) and average maximum mass (M∞) varied significantly among regions, suggesting that productivity of L. miniatus is likely to vary among regions of the GBR. There was also significantly greater mass of fish for a given LF in two regions, which magnified the regional differences in M∞. The observed temporal and spatial variation in growth highlighted the importance of a multi-scale approach to population studies and assessment of fish stocks.