Identifying relationships between adult and juvenile bivalves at different spatial scales

The variable results of field experiments on adult-juvenile interactions suggest that, under natural conditions, other processes may be more important. However, field surveys are less equivocal. A potential reason for this is that surveys, integrating information over larger scales than experiments, have a greater ability to match the scale of processes. In this survey, a transect design was utilised, with samples 1 m apart nested within samples 5 m apart, at three sites located 1 km apart on a homogeneous sandflat. Correlations between adult and juvenile bivalves were analysed for a variety of distances apart (0 to 80 m) and spatial extents (m to 1 km). Different intensities and directions of relationships were observed at different scales and at different sites. This study supports the hypothesis that processes of a larger scale than those commonly examined in small-scale field experiments may contribute to the variability of results of adult-juvenile interaction experiments. (C) 1997 Elsevier Science B.V.