In preparation for a forthcoming monitoring project, a shallow subtidal area in the northern Wadden Sea was studied for macrozoobenthos >1 mm sieve size. Using a Reineck-type box-corer of 0.02 m² surface area, abundance and specific composition were evaluated from a sampling grid of 21 positions with two replicates each. Temporarily, sampling was repeated 9 times. Analyses of spatial and temporal variability revealed that within-site variability was far lower than between-site variability. As a consequence, the later monitoring project was based on a higher number of study sites at the cost of within-site replication.