Adapting the CHEMTAX method for assessing phytoplankton taxonomic composition in southeastern U.S. estuaries

Alan J. Lewitus, David L. White, Raphael G. Tymowski, Mark E. Geesey, Sabrina N. Hymel, Peter A. Noble

Research output: Contribution to journalArticlepeer-review

95 Scopus citations


CHEMTAX is a matrix factorization program used to derive taxonomic structure of phytoplankton from photosynthetic pigment ratios. The program was originally developed from and applied to the analysis of oceanic phytoplankton assemblages. We found that application of the original CHEMTAX reference matrix to southeastern United States estuarine systems produced inaccurate results, as verified by microscopy. Modification of the matrix, based primarily on the pigment ratios of 33 estuarine isolates, unproved the predictive capabilities of CHEMTAX for our samples. Limitations of the method included an overestimation of diatom biomass (due to the inability to differentiate diatoms from taxa with chloroplasts derived from diatom endosymbionts, notably some dinoflagellates) and a tendency to exclude some raphidophyte species. In complement with microscopic verification, the method was shown to improve assessment of phytoplankton taxonomic composition.

Original languageEnglish (US)
Pages (from-to)160-172
Number of pages13
Issue number1
StatePublished - Feb 2005

Bibliographical note

Funding Information:
We m'e grateful to Jennifer Keesee for her significemt assistance in sampling and sample processing, Ivy Collins for help with HPLC analy3is, Jennifer Wolny for help in species identification, and Ken Hayes fbr technical assistance. Ttis study was fm~ded by the U.S. Ecology and Oceanography of Harmful ~-ga.1 Blooms (ECOHAB) Program, sponsored by NOAA/NSF/ EPA/NASA/ONR, grant NA16OP2796, NOAA grants NA90AA-D-SC672 and NA06OA0675, CDC grant US0/CU482274, EPA grant R82694ee01-0, and EPA-CEER-GOM Grant R-82945801. Contribution 1402 of the Be:fie W, Baruch Institute for Marine Biology and Coastal Resem'ch, Contribution 555 of South Cm'-olina Department of Natural Resom'ce's Mmine Resources Research Institute, ECOF-L~,B Contribution 122.


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