A workshop was held 6-16 January 2008 to evaluate the ability of various analysis methods to detect, enumerate, and determine the viability of phytoplankton at concentrations to be expected after treatment by successful ballast water treatment systems. Researchers from Woods Hole Oceanographic Institute, Moss Landing Marine Laboratory, Naval Research Laboratory, and Fluid Imaging Technologies were provided with six samples with known concentrations of live and dead Tetraselmis species in prepared ...