First harmful Dinophysis (Dinophyceae, Dinophysiales) bloom in the U.S. is revealed by automated imaging flow cytometry

2010

Authors

• Lisa Campbell Texas A&M University Department of Oceanography , Texas A&M University Department of Biology
• Robert J. Olson Woods Hole Oceanographic Institution Biology Department
• Heidi M. Sosik Woods Hole Oceanographic Institution Biology Department
• Ann Abraham U.S. Food and Drug Administration Gulf Coast Seafood Laboratory
• Darren W. Henrichs Texas A&M University Department of Biology
• Cammie J. Hyatt The University of Texas at Austin Marine Science Institute
• Edward J. Buskey The University of Texas at Austin Marine Science Institute

Description

Imaging FlowCytobot (IFCB) combines video and flow cytometric technology to capture images of nano- and microplankton ([?]10 to >100 mm) and to measure the chlorophyll fluorescence associated with each image. The images are of sufficient resolution to identify many organisms to genus or even species level. IFCB has provided >200 million images since its installation at the entrance to the Mission-Aransas estuary (Port Aransas, TX, USA) in September 2007. In early February 2008, Dinophysis cells (1-5 * mL[?]1) were detected by manual inspection of images; by late February, abundance estimates exceeded 200 cells * mL[?]1. Manual microscopy of water samples from the site confirmed that D. cf. ovum F. Schutt was the dominant species, with cell concentrations similar to those calculated from IFCB data, and toxin analyses showed that okadaic acid was present, which led to closing of shellfish harvesting. Analysis of the time series using automated image classification (extraction of image features and supervised machine learning algorithms) revealed a dynamic phytoplankton community composition. Before the Dinophysis bloom, Myrionecta rubra (a prey item of Dinophysis) was observed, and another potentially toxic dinoflagellate, Prorocentrum, was observed after the bloom. Dinophysis cell-division rates, as estimated from the frequency of dividing cells, were the highest at the beginning of the bloom. Considered on a daily basis, cell concentration increased roughly exponentially up to the bloom peak, but closer inspection revealed that the increases generally occurred when the direction of water flow was into the estuary, suggesting the source of the bloom was offshore.

Journal of Phycology volume 46 pages 66-75

DOI : 10.1111/j.1529-8817.2009.00791.x

Cited by chapter 6, and usgcrp-climate-human-health-assessment-2016. (reference: 92302697)