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analysis using Moran's and Geary's coefficients. An initial assessment of the spatial
patterns of P. elegans will help identify which processes possibly determine this
species' spatial distribution on Drum Sands and therefore the focus of successive
research. The main aims of this study were:
1 - to investigate the small- and meso-scale spatial distributions of macrobenthic
invertebrate species and sediment variables on an intertidal sandflat;
2 - to determine whether the abundance of this dominant species was associated with
the spatial pattern of other species.
This was accomplished firstly by an investigation into the scales of spatial variability
using analysis of variance; this `transece survey was also to serve as a pilot survey. A
pilot survey was considered necessary to assess the macrofaunal densities and the
scales of variability present. A more detailed investigation of spatial patterns was then
carried out using three grid surveys, each conducted at different spatial scales. Since
patchiness may occur at many scales (Kotliar and Wiens, 1990) it is necessary to
sample as many scales as possible since whether a pattern is detected or not is a
function of the sampling regime (Legendre and Fortin, 1989). For example, with
spatial autocorrelation analysis, patches can only be detected if the spacing of the
samples is on average less than the average diameter of a patch (Sokal and
Wartenberg, 1981).
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