The distribution of estuarine diatoms along environmental gradients: A canonical correlation

Abstract

Multivariate statistical procedures identified groups of non-planktonic diatoms with similar distributions in Yaquina Estuary (Oregon). A clustering algorithm and a canonical analysis of discriminance were used to describe distributional patterns relative to the pattern of sampling, and these patterns were associated with environmental gradients by the method of canonical correlation. There was a distributional continuum of marine and brackish-water diatom taxa that changed location in the estuary with seasonal variation in freshwater discharge. However, the vertical and horizontal gradients of salinity and desiccation were steep enough to manifest three relatively discrete assemblages, one with typical freshwater taxa and two dominated by species of Melosira and Achnanthes. About 41% of the variability in the species data could be associated with salinity, temperature, light energy, and period of exposure to intertidal emergence. Canonical correlation ordered 26 taxa along gradients of mean salinity and mean daily salinity range.