Variation in copepod species assemblage distributions: The utility of the log-normal approach

Pelagic copepod species distributions were found to vary in relation to an environmental gradient. As suggested by Gray, systematic changes were noted in the skewness of the log-normal. However, no systematic changes in the standard of deviation of the log-normal were noted. The data indicate that such assemblages ill-fit Preston's ‘canonical’ expectation. Further, analysis of changes in the evenness function yielded similar conclusions.