RESUMO
The sampling effort for detecting taxonomic distinctness of periphytic diatom communities was studied in coastal waters of the Yellow Sea, northern China, from May to June 2014. Samples with different sizes (microscopy glass slides) were collected at two depths of 1m and 3m. To obtain the communities with dissimilarities of <10%, 2 slide replicates were sufficient for sampling at a depth of 1m, while 4 were required for the those at a depth of 3m. The values of four taxonomic distinctness indices represented a low sensitivity to sample sizes over all exposure period ages: at a coefficient of variation of <10%, 2 and 9 slide replicates were required at a depth of 1m and 3m, respectively. We suggest that the sampling strategy of the diatoms for detecting taxonomic distinctness might be better at 1m than at a deeper layer in coastal waters.