title: Influence of sampling sufficiency on biodiversity analysis of microperiphyton communities for marine bioassessment.
abstract: BACKGROUND
  With quick responses to environmental changes, easy sampling, relative immobility, increasing availability of easily used taxonomic references, and allowing standardization for temporal and spatial comparisons, the biodiversity measures of microperiphyton communities have widely been accepted as useful indicators to evaluate environmental stress and anthropogenic impact.
  
  
  METHODS
  The influence of sampling sufficiency for biodiversity analysis of microperiphyton communities was studied using a range of statistical methods in coastal waters of the Yellow Sea, northern China, from May to June 2010. Samples were collected from two depths using an artificial substrate.
  
  
  RESULTS
  Sampling sizes represented a significant influence on biodiversity analysis of microperiphyton communities, e.g., 20 slide replicates (350 cm(2)) were sufficient for the microperiphyton communities at both depths, while 10 slide replicates (175 cm(2)) could meet the sampling strategy only for the samples with colonization times of 10 days or more at a depth of 1 m for recovering 90% species during the study period. Otherwise, more slide replicates were required with the increase of water depths and shortening colonization times for recovering microperiphyton species, e.g., for recovering 90% species of a "mature" microperiphyton community (>10 days), ∼10 slide replicates (∼175 cm(2)) were sufficient at a depth of 1 m, while for the "young" samples (>10 days) much more (15-30) slide replicates were required at both depths in this study. Furthermore, to achieve <10% standard errors, six (105 cm(2)) and nine (∼160 cm(2)) slide replicates were required for biodiversity analysis of the microperiphyton communities with various colonization times at depths of 1 and 3 m during the summer season, respectively.
  
  
  CONCLUSIONS
  These results suggest that sampling sizes represented a significant influence on biodiversity analysis of microperiphyton communities for monitoring programs and ecological conservation researches in marine ecosystems.
authors.affiliation: Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China. henglongxu@126.com
authors.forename: Henglong
authors.initials: H
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Jiang
authors.forename: Mingzhuang
authors.initials: M
authors.lastname: Zhu
authors.forename: Khaled A S
authors.initials: KA
authors.lastname: Al-Rasheid
mesh_terms: D044822:Biodiversity; D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D058086:Microalgae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D009792:Oceans and Seas; D011157:Population Dynamics; D012621:Seasons; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants