INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
An evaluation of the application of CHEMTAX to Antarctic coastal pigment data
KOZLOWSKI, W.; DEUTSCHMAN, D.; GARIBOTTI, I.A.; TREES, C.; VERNET, M.
DEEP-SEA RESEARCH. PART 1. OCEANOGRAPHIC RESEARCH PAPERS
PERGAMON-ELSEVIER SCIENCE LTD
Año: 2011 vol. 58 p. 350 - 350
The CHEMTAX (CHEMical TAXonomy) program is a chemotaxonomic tool used to determine phytoplankton composition based on photosynthetic pigment ratios. Although not as detailed as microscopy, it has three important advantages: it allows for non-unique pigment markers in phytoplankton groups, it is not dependent on sample preservation and includes all cell sizes, in particular the <5 micrometer cells, and once pigment data is obtained, it allows for large number of samples to be processed relatively quickly. In this study we present an evaluation of the application of CHEMTAX to Antarctic coastal pigments collected along the western Antarctic Peninsula (wAP). Overall analytical error is <20% for all pigments involved in the analysis. CHEMTAX was stable within a range of input pigment ratios; data were analyzed in three bins based on light depths, with each years data run independently. Results were validated by comparison to those from CHEMTAX methods that included randomized error, feedback loops and additional diagnostic pigments. Blooms during mid-summer (chlorophyll a concentrations >5 ìg L-1) were dominated primarily by either diatoms or cryptomonads. Mixed flagellates can also be abundant and Pheaocystis spp. and prasinophytes are frequently present in low concentrations. Comparison with microscopy shows CHEMTAX to give superior results in identifying Pheaocystis spp. with favorable results for other groups. This analysis shows CHEMTAX to be a reliable and stable tool for providing estimations of the main phytoplankton taxa in wAP waters based on long-term data collected during a 13-year time series.