Kate Hubbard

Extensive diversity has been detected in phytoplankton communities, and while some organisms appear to be ubiquitously distributed throughout the marine environment, other organisms appear to be constrained to particular places or environments. I am interested in the connection between diversity and distribution across different environments, and more specifically, how physiology, dispersal, and (physical and chemical) environment may structure marine diatom communities. For my graduate studies, I am surveying genetic diversity in the harmful alga, Pseudo-nitzschia. Most of my research takes place in the coastal and estuarine waters of British Columbia and Washington, although I am interested in the global distribution of Pseudo-nitzschia (and welcome potential sampling collaborations). This research is being conducted as part of the Pacific Northwest Center for Human Health and Ocean Studies, a multi-disciplinary investigation to understand how harmful algae blooms are initiated in the marine environment, and the impacts they have on shellfish and humans (and vice versa). The genus Pseudo-nitzschia is comprised of some 30 species, and is perhaps best known because many species are able to produce the neurotoxin domoic acid. Diatoms in this genus also exhibit a cosmopolitan distribution, with species detected in all oceans including polar regions. Individual species, however, can be notoriously difficult to identify. For my master's research, I designed genus specific primers and developed a Pseudo-nitzschia Automated Intergenic Spacer Analysis (ARISA) to easily and accurately identify species in environmental samples (Hubbard et al. 2008). ARISA can be used in tandem with environmental clone libraries to identify diversity at the species and sub-species levels. For my PhD research, I am using these approaches to identify population structure (in toxic and non-toxic blooms), across coastal and estuarine environmental gradients (e.g. salinity). Ecological investigations of distribution patterns, coupled with circulation models, will be used to make predictions about the impact of physiology and physical oceanography on dispersal, which will be tested using Pseudo-nitzschia isolates in laboratory experiments. Education: M.S. in Oceanography, University of Washington, 2005. B.A. in Biology, New College of Florida, 2002. Recent publications: Hubbard, K.A., Rocap, G., and Armbrust, E.V. 2008. Inter- and intra-specific community structure within the diatom genus Pseudo-nitzschia (Bacillariophyceae). J. Phycol. 44 (3) 637-649. Marchetti, A., Lundholm, N., Kotaki, Y., Hubbard, K.A., Armbrust, E.V., and Harrison, P.J. 2007. Identification and assessment of domoic acid production in oceanic Pseudo-nitzschia (Bacillariophyceae) from iron-limited waters in the northeast subarctic Pacific. J. Phycol. 44 (3) 650-661.

Hood Canal in February, 2008

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