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Enhanced monitoring of harmful algal bloom dynamics and toxicity using real-time observations from co-deployed, automated biosensors

PIs: Donald M. Anderson, Michael L. Brosnahan, Juliette L. Smith, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543 and Gregory J. Doucette NOAA/NOS/NCCOS - Marine Biotoxins Program, Charleston, S.C., 29412

Blooms of the dinoflagellate Alexandrium fundyense cause annual shellfish closures along the Maine, New Hampshire, and Massachusetts coasts due to paralytic shellfish poisoning (PSP), a life- threatening seafood poisoning syndrome that can cause death through central nervous system paralysis to consumers of contaminated shellfish. Other closely related species also cause PSP and are globally dispersed, making PSP the most widespread harmful algal bloom (HAB) associated poisoning syndrome. Monitoring for PSP is costly and fishery closures have direct negative impacts on both recreational and commercial shellfish harvesters. Closures due to PSP also impose additional costs that are transferred to the tourism and restaurant industries (Jin et al., 2005).

The serious hazard posed by these blooms has helped spur the development of several automated in situ biosensors that are capable of monitoring A. fundyense cell abundance and, in one case, to concurrently measure concentrations of PSP toxins (PSTs), which themselves are chemically diverse and exhibit a wide range of toxicities (Anderson et al., 1994). While research has established that A. fundyenseabundance and their toxicity can vary widely both seasonally and annually, significant gaps in our knowledge of A. fundyense blooms include the extent to which environmental factors modulate bloom toxicity, the ecological advantage conferred by PST production, and the role of life cycle transitions in determining bloom toxicity. Here we propose a simultaneous deployment of two of these new biosensors, the Imaging FlowCytobot (IFCB) and the Environmental Sample Processor (ESP) through modifications to an existing raft platform. We will also refine an existing PST sensor for the ESP and exploit the combined strengths of the IFCB and ESP PST assay to investigate linkages between bloom dynamics, toxin production, and shellfish toxicity in situ. These instruments are highly complimentary and thus the concurrent deployment greatly expands their individual capabilities. The joint deployment is planned for Salt Pond (Eastham, MA), a small kettle pond within the Nauset Marsh estuary (NME) that experiences annual, localized A. fundyense blooms. The deployment will record a complete seasonal bloom cycle in this system – from its development through its decline – giving us an unprecedented look into the life history and toxin dynamics that underlie PSP events and lead to contamination of shellfish resources.