Bibliografía: páginas 39-46

Chemical analysis, although valuable and necessary, does not provide all the information required in pollution assessments. Biological studies are of particular value in permitting a realistic assessment of pollution and they cover a wide range of possibilities. The present manual makes only cursory reference to the techniques used to study the sub lethal toxic effects at the individual level of organization or below since it is devoted to biological studies at community level and especially to the use of benthos. It describes how a benthic sampling program should be designed so that the data collected can be best interpreted and evaluated. Information is provided for the collection and treatment of the samples as well as for the analysis of the data using statistical methods and computer software. Multivariate analysis techniques include hierarchical clustering, multi-dimensional scaling (MDS) ordination and principal components analysis (PCA). Inglés