Sampling effort of periphytic diatoms for bioassessment research using taxonomic distinctness in marine ecosystems: A case study in coastal waters

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 1 m and 3 m. To obtain the communities with dissimilarities of < 10%, 2 slide replicates were sufficient for sampling at a depth of 1 m, while 4 were required for the those at a depth of 3 m. 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 1 m and 3 m, respectively. We suggest that the sampling strategy of the diatoms for detecting taxonomic distinctness might be better at 1 m than at a deeper layer in coastal waters.