Comparison of techniques used to count single-celled viable phytoplankton
Steinberg, Mia K.
First, Matthew R.
Lemieux, Edward J.
Drake, Lisa A.
Nelson, Bruce N.
Kulis, David M.
Anderson, Donald M.
Welschmeyer, Nicholas A.
Herring, Penny R.
MetadataShow full item record
KeywordPhytoplankton; Enumeration; FlowCAM; Flow cytometry; Sedgewick Rafter; Ballast water; SYTOX Green; CellTracker Green
Four methods commonly used to count phytoplankton were evaluated based upon the precision of concentration estimates: Sedgewick Rafter and membrane filter direct counts, flow cytometry, and flow-based imaging cytometry (FlowCAM). Counting methods were all able to estimate the cell concentrations, categorize cells into size classes, and determine cell viability using fluorescent probes. These criteria are essential to determine whether discharged ballast water complies with international standards that limit the concentration of viable planktonic organisms based on size class. Samples containing unknown concentrations of live and UV-inactivated phytoflagellates (Tetraselmis impellucida) were formulated to have low concentrations (<100 ml-1) of viable phytoplankton. All count methods used chlorophyll a fluorescence to detect cells and SYTOX fluorescence to detect non-viable cells. With the exception of one sample, the methods generated live and non-viable cell counts that were significantly different from each other, although estimates were generally within 100% of the ensemble mean of all subsamples from all methods. Overall, percent coefficient of variation (CV) among sample replicates was lowest in membrane filtration sample replicates, and CVs for all four counting methods were usually lower than 30% (although instances of ~60% were observed). Since all four methods were generally appropriate for monitoring discharged ballast water, ancillary considerations (e.g., ease of analysis, sample processing rate, sample size, etc.) become critical factors for choosing the optimal phytoplankton counting method.
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Applied Phycology 24 (2012): 751-758, doi:10.1007/s10811-011-9694-z.
Showing items related by title, author, creator and subject.
Mecking, Sabine; Warner, Mark J.; Greene, Catherine E.; Hautala, Susan L.; Sonnerup, Rolf E. (American Geophysical Union, 2004-07-17)A diagnostic, isopycnal advection-diffusion model based on a climatological, geostrophic flow field is used to study the uptake of chlorofluorocarbons (CFCs) into the portion of the thermocline that outcrops in the open ...
Analysis of apparent optical properties and ocean color models using measurements of seawater constituents in New England continental shelf surface waters Green, Rebecca E.; Sosik, Heidi M. (American Geophysical Union, 2004-03-17)We used budgets of absorption (a), scattering (b), and backscattering (bb) for particles and chromophoric dissolved organic matter (CDOM) to investigate sources of seasonal variations in apparent optical properties (AOPs) ...
Hydrothermal sediments as a potential record of seawater Nd isotope compositions : the Rainbow vent site (36°14′N, Mid-Atlantic Ridge) Chavagnac, Valerie; Palmer, Martin R.; Milton, J. Andrew; Green, Darryl R. H.; German, Christopher R. (American Geophysical Union, 2006-09-09)Geochemical compositions and Sr and Nd isotopes were measured in two cores collected ~2 and 5 km from the Rainbow hydrothermal vent site on the Mid-Atlantic Ridge. Overall, the cores record enrichments in Fe and other ...