Scales and magnitudes of variation in population densities of some coral reef organisms : implications for the design of sampling and monitoring procedures

In this report we have concentrated on the description of variation in abundances of several coral reef organisms in the Cairns Section of the Great Barrier Reef (GBR) Marine Park. Our focus was on the implications of spatial variation for the design of sampling and monitoring programmes and the inference of spatial pattern. Patterns of interest might arise, for example, from effects of areabased management strategies or human impacts on the reef environment. The data we present indicate that spatial variation is large at most scales for most organisms. Consequently, it is unlikely that small or even moderate spatial patterns caused by management strategies, human use, or natural perturbations will be detectable reliably without considerable expense