An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Legacy Publications Explorer

You are here: Publications / Publication Details

Publication Details

Please note this explorer contains 2017 and prior publications and is no longer updated. Visit Data Reports Explorer for the latest NCCOS research data and reports.

Factors regulating excystment of Alexandrium in Puget Sound, WA, USA

Author(s): Moore, Stephanie K.; Brian D. Bill; Levi R. Hay; Jennifer Emenegger; Kiara C. Eldred; Cheryl L. Greengrove; Julie E. Masura; Donald M. Anderson

NCCOS Center: CSCOR

Name of Publisher: Elsevier

Publication Type: Journal Article

Journal Title: Harmful Algae

Date of Publication: 2015

Reference Information: 43: 103-110

Keywords: Alexandrium; Puget Sound; Excystment; Cysts; Harmful algal bloom; Red tide; ECOHAB

Abstract: Factors regulating excystment of a toxic dinoflagellate in the genus Alexandrium were investigated in cysts from Puget Sound, Washington State, USA. Experiments were carried out in the laboratory using cysts collected from benthic seedbeds to determine if excystment is controlled by internal or environmental factors. The results suggest that the timing of germination is not tightly controlled by an endogenous clock, though there is a suggestion of a cyclical pattern. This was explored using cysts that had been stored under cold (4 °C), anoxic conditions in the dark and then incubated for 6 weeks at constant favorable environmental conditions. Excystment occurred during all months of the year, with variable excystment success ranging from 31–90%. When cysts were isolated directly from freshly collected sediments every month and incubated at the in situ bottom water temperature, a seasonal pattern in excystment was observed that was independent of temperature. This pattern may be consistent with secondary dormancy, an externally modulated pattern that prevents excystment during periods that are not favorable for sustained vegetative growth. However, observation over more annual cycles is required and the duration of the mandatory dormancy period of these cysts must be determined before the seasonality of germination can be fully characterized in Alexandrium from Puget Sound. Both temperature and light were found to be important environmental factors regulating excystment, with the highest rates of excystment observed for the warmest temperature treatment (20 °C) and in the light.

Availability: Available from NCCOS Projects Explorer and from the journal.

Related Attachment: Download file (.pdf)


Note to readers with disabilities: Some scientific publications linked from this website may not conform to Section 508 accessibility standards due to the complexity of the information being presented. If you need assistance accessing this electronic content, please contact the lead/corresponding author, Primary Contact, or nccos.webcontent@noaa.gov.