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dc.contributor.authorVahtera, Emil  Concept link
dc.contributor.authorCrespo, Bibiana G.  Concept link
dc.contributor.authorMcGillicuddy, Dennis J.  Concept link
dc.contributor.authorOlli, Kalle  Concept link
dc.contributor.authorAnderson, Donald M.  Concept link
dc.date.accessioned2014-08-07T15:58:08Z
dc.date.available2014-08-07T15:58:08Z
dc.date.issued2013-05
dc.identifier.urihttps://hdl.handle.net/1912/6792
dc.descriptionAuthor Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 103 (2014): 112–119, doi:10.1016/j.dsr2.2013.05.010.en_US
dc.description.abstractBoth observations and models suggest that large-scale coastal blooms of Alexandrium fundyense in the Gulf of Maine are seeded by deep-bottom cyst accumulation zones (“seed beds”) where cysts germinate from the sediment surface or the overlying near-bottom nepheloid layers at water depths exceeding 100 m. The germling cells and their vegetative progeny are assumed to be subject to modest mortality while in complete darkness as they swim to illuminated surface waters. To test the validity of this assumption we investigated in the laboratory cyst viability and the survival of the germling cells and their vegetative progeny during prolonged exposure to darkness at a temperature of 6°C, simulating the conditions in deep Gulf of Maine waters. We isolated cysts from bottom sediments collected in the Gulf of Maine under low red light and incubated them in 96-well tissue culture-plates in culture medium under a 10:14h light: dark cycle and under complete darkness. Cyst viability was high, with excystment frequency reaching 90% in the illuminated treatment after 30 days and in the dark treatment after 50 days. Average germination rates were 0.062 and 0.038 d-1 for light and dark treatments, respectively. The dark treatment showed an approximately two-week time lag in maximum germination rates when compared to the light treatment. Survival of germlings was considerably lower in the dark treatment. In light treatments, 47% of germinated cysts produced germlings that were able to survive for 7 days and produce vegetative progeny, i.e. there were live cells in the well along with an empty cyst at least once during the experiment. In the dark treatments 12% of cysts produced germlings that were able to survive. When dark treatments are scaled to take into account non-darkness related mortality, approximately 28% of cysts produced germlings that were able to survive for at least 7 days. Even though cysts are able to germinate in darkness, the lack of illumination considerably reduces survival rate of germling cells. In addition to viability of cysts in surface sediments and the near-bottom nepheloid layer, survivability of germling cells and their vegetative progeny at aphotic depths is an important consideration in assessing the quantitative role of deep-coastal cyst seed beds in bloom formation.en_US
dc.description.sponsorshipE. Vahtera was funded by the Academy of Finland (grant #130934) and B. Gomez-Crespo was supported by a Xunta de Galicia Ángeles Alvariño fellowship. Additional funding support was also provided by the National Oceanic Atmospheric Administration ECOHAB program through grants NA06NOS4780245 and NA09NOS4780193 and from National Science Foundation grants OCE- 0430724 and OCE-0911031 and National Institute of Environmental Health Sciences grant 1P50- ES01274201 through the Woods Hole Center for Oceans and Human Health.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.relation.urihttps://doi.org/10.1016/j.dsr2.2013.05.010
dc.titleAlexandrium fundyense cyst viability and germling survival in light vs. dark at a constant low temperatureen_US
dc.typePreprinten_US


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