b'FEATURE STORY CELL COUNTRed tides are a type of Harmful Algal Bloom caused by dinoflagellates like Karenia brevis. Sourced: National Science FoundationThe question on the publics mind is often Is it safe to go to theThe microscope is slowly beach? Whether the answeryielding to technologies that are is sought from the Floridafaster, more sensitive and less Department of Health or theprone to variability between Centers for Disease Control, bothtechnicians. The advantages of will ultimately point your browserspeed were realized years ago to the FWCs Red TideStatus updates. 6 when technicians starting using Coulter counters, electronic particle The FWC publishes cell counts ofcounters not originally designed for Karenia brevis from over 100 sitesthis purpose, but which afforded not along Floridas beaches and posts themonly speed but also highly accurate and on a weekly basis (usually Fridays), or morereproducible counts, reducing subjectivityfrequently during severe events. and technician-to-technician variability.There is easy-to-understand information about howHowever, the Coulter is an agnostic technology, to interpret the cell counts, including a color-codedcounting any electrically charged particle in the scale that ranges from not present (gray, for <1000sample and offering no speciation.Thus counters cells/L) to high (red, for >1,000,000 cells/L). Inwere often used in conjunction with, rather than addition to their routine monitoring, FWC scientistsinstead of, the microscope.respond to calls from other sites where a red tide isExciting new technologies offer the best of all worlds:suspected. An easy way to follow this program is atspeed, high sensitivity, high accuracy, and speciation their Facebook page, co-maintained with the Mote(even photos!), all possible via sorting based on the Marine Laboratory. fluorescent properties of the algal cells. One of the best examples is the FlowCam by FluidRed Tide Status on Facebook:Imaging Technologies. 7 facebook.com/flhabs With the FlowCam, and similar competing technologies that are now appearing on the market, much ado has been made about the comparability of The FWCs program of collecting water samplesthe counts with microscope counts, due to the desire for cell enumeration with a microscope may seemto maintain continuity in decades-old data sets.old-fashioned to a molecularly-biased, high-tech-sensor-loving, post-millennial generation of scientists.However, a number of cases have shown that However, microscopy remains highly valuable forreproducibility from technician to technician is even a number of reasons. First, a skilled technician candifficult to ensure with the microscope, a realization rapidly and reproducibly count K. brevis samplesthat has probably eased the comfort people have with (not true of all algae!), and the equipment is easilythe FlowCam. The biggest accessible and inexpensive.barrier to its use appears to be expense, but the Further, there are decades of cell count data availablereturn on investment for comparison. Floridas HAB Monitoring Databasein technician time is one of the longest, continually maintained datasetsand reliable results of any type, and shows that red tides have beenseem to now be documented in Florida as far back as 170 years. Thisappreciated.continuity of data has been critical for demonstrating that red tides are not new to Florida, a sticky point when trying to assess red tides as natural events which at the same time can be fueled by human activity and climate change. 6 FWC, Red Tide Current Status7 Fluid Imaging, Microalgae Research and Industrial Cultivation22 MISSION: WATER'