The annual occurrence of Karenia brevis in the Gulk of Mexico is one of the most significant harmfulalgal blooms (HABs) in the coastal waters of the United States. This HAB species has a large economic,health, and environmental impact on Gulf coast communities, especially in Florida, through massive fishkills, deaths of marine mammals and birds, human consumption of toxin-contaminated seafood, andrespiratory effects from aerosolized toxins. Over the past few decades the incidence of K. brevis bloomsappears to be increasing in both frequency and duration. Current government-mandated programs formonitoring this HAB species must rely on microscopic cell counts. These counts are time consuming, havelow sample through-put, and require highly-skilled microscopists who are experts at identifying andenumerating Karenia brevis cells of varying morphologies in complex natural phytoplankton assemblages.There is consensus among HAB researchers and public health professionals that monitoring efforts forHABs must evolve towards the use of rapid, accurate, sensitive, and objective molecular-based detectionand quantitation methods.The proposed project will first utilize a combination of molecular techniques, such as Fluorescent In SituHybridization (FISH) and real-time quantitative polymerase chain reaction (qPCR), with traditional methods(light and fluorescent microscopy) to enumerate Karenia brevis cells in laboratory cultures. The objective ofthis initial phase is to test the efficacy of, and where feasible optimize, molecular methodologies with ashort (3-5 hour) processing time for use in natural populations. Second, we will apply a combination ofmetabolic measurements (cell division, photosynthesis and respiration rates) and flow cytometrymethodologies in cultures, and then natural popualtiosn, to improve our understanding of howenvironmental factors influence the metabolic state of K. brevis. Third, we will attempt to relate theseindices to environmental parameters. The ultimate objective of this research is to facilitate the idenitficationand enumeration of this HAB species, and develop near real-time indices to assess the metabolic state ofKarenia brevis in various stages of bloom development.Significance: It is anticipated that the results of this project will enhance our understanding of whatfactors contribute to Karenia bloom development. It will also synergistically enhance other collaborativeHAB research programs through a rapid-response sampling program and sharing of samples and data.
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