This research will identify and model the biological and physical mechanisms regulating two key processes in the blooms of Alexandrium dinoflagellates responsible for paralytic shellfish poisoning (PSP): bloom initiation and termination. A key feature of the project is that it will be conducted in the Nauset Marsh System (NMS), a shallow estuary that has recurrent A. fundyense blooms in its three terminal kettie ponds, with blooms being unequivocally tied to cyst seedbeds in those embayments. The NMS represents a natural """"""""mesocosm"""""""" where these processes can be studied in a manner not possible in open coastal waters. The NMS also represents a major habitat for toxic Alexandrium species in the US and worldwide.
Aim 1 comprises field and lab experiments on bloom initiation. Excystment experiments will determine whether internal or external factors regulate germination seasonality, and other studies will measure the effects of temperature, salinity, and light on germination and growth. The timing and rate of escape of germinated cells will be measured using plankton emergence traps, and high-resolution sampling will be conducted throughout bloom initiation.
Aim 2 activities are focused on bloom termination. A unique submersible flow cytometer with imaging capabilities (the imaging flow cytobot, IFCB) will detect life cycle transitions in situ. Routine and adaptive field sampling (triggered by IFCB data) will document factors associated with life cycle transitions, and sediment traps will assess the timing and rate of cyst deposition. Complimentary efforts will utilize a bentop multi-daser IFCB to confirm the presence of sexual forms in field samples, an assessment of the linkage between A. fundyense encystment and parasite infection, and the development of biomarker assays for detection of gametes and planozygotes that will be applied in sampling for these stages in situ.
In Aim 3, an innovative Lagrangian approach will model Alexandrium population dynamics within the NMS, including life cycle transitions. The model will be formulated and calibrated against blooms in the NMS, but is broadly transferable to HAB models in estuarine or coastal settings, including Project 2 in this program.
PSP is the most widespread HAB poisoning syndrome. This project thus has significant relevance to resource managers, public health professionals, consumers of seafood, and local economies dependent on the shellfish industry. This project addresses the COHH goal of supporting research that can reduce public health risks, and it addresses the priority area of enhancing prediction of HAB events.
|Ganju, Neil K; Brush, Mark J; Rashleigh, Brenda et al. (2016) Progress and challenges in coupled hydrodynamic-ecological estuarine modeling. Estuaries and coasts : journal of the Estuarine Research Federa 39:311-332|
|Sehein, Taylor; Richlen, Mindy L; Nagai, Satoshi et al. (2016) CHARACTERIZATION OF 17 NEW MICROSATELLITE MARKERS FOR THE DINOFLAGELLATE ALEXANDRIUM FUNDYENSE (DINOPHYCEAE), A HARMFUL ALGAL BLOOM SPECIES. J Appl Phycol 28:1677-1681|
|Han, Myungsoo; Lee, Haeok; Anderson, Donald M et al. (2016) Paralytic shellfish toxin production by the dinoflagellate Alexandrium pacificum (Chinhae Bay, Korea) in axenic, nutrient-limited chemostat cultures and nutrient-enriched batch cultures. Mar Pollut Bull 104:34-43|
|Roncalli, Vittoria; Turner, Jefferson T; Kulis, David et al. (2016) The effect of the toxic dinoflagellate Alexandrium fundyense on the fitness of the calanoid copepod Calanus finmarchicus. Harmful Algae 51:56-66|
|Glazer, Lilah; Hahn, Mark E; Aluru, Neelakanteswar (2016) Delayed effects of developmental exposure to low levels of the aryl hydrocarbon receptor agonist 3,3',4,4',5-pentachlorobiphenyl (PCB126) on adult zebrafish behavior. Neurotoxicology 52:134-43|
|Richlen, Mindy L; Zielinski, Oliver; Holinde, Lars et al. (2016) Distribution of Alexandrium fundyense (Dinophyceae) cysts in Greenland and Iceland, with an emphasis on viability and growth in the Arctic. Mar Ecol Prog Ser 547:33-46|
|Xu, Yixiao; Richlen, Mindy L; Liefer, Justin D et al. (2016) Influence of Environmental Variables on Gambierdiscus spp. (Dinophyceae) Growth and Distribution. PLoS One 11:e0153197|
|Bill, Brian D; Moore, Stephanie K; Hay, Levi R et al. (2016) Effects of temperature and salinity on the growth of Alexandrium (Dinophyceae) isolates from the Salish Sea. J Phycol 52:230-8|
|Lemaire, Benjamin; Kubota, Akira; O'Meara, Conor M et al. (2016) Cytochrome P450 20A1 in zebrafish: Cloning, regulation and potential involvement in hyperactivity disorders. Toxicol Appl Pharmacol 296:73-84|
|Ralston, David K; Brosnahan, Michael L; Fox, Sophia E et al. (2015) Temperature and residence time controls on an estuarine harmful algal bloom: Modeling hydrodynamics and Alexandrium fundyense in Nauset estuary. Estuaries and coasts : journal of the Estuarine Research Federa 38:2240-2258|
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