title: IDENTIFICATION AND ASSESSMENT OF DOMOIC ACID PRODUCTION IN OCEANIC PSEUDO-NITZSCHIA (BACILLARIOPHYCEAE) FROM IRON-LIMITED WATERS IN THE NORTHEAST SUBARCTIC PACIFIC(1).
abstract: We identified and investigated the potential toxicity of oceanic Pseudo-nitzschia species from Ocean Station Papa (OSP), located in a high-nitrate, low-chlorophyll (HNLC) region of the northeast (NE) subarctic Pacific Ocean. Despite their relatively low abundances in the indigenous phytoplankton assemblage, Pseudo-nitzschia species richness is high. The morphometric characteristics of five oceanic Pseudo-nitzschia isolates from at least four species are described using SEM and TEM. The species identified are Pseudo-nitzschia dolorosa Lundholm et Moestrup, P. granii Hasle, P. heimii Manguin, and P. cf. turgidula (Hust.) Hasle. Additional support for the taxonomic classifications based on frustule morphology is provided through the sequencing of the internal transcribed spacer 1 (ITS1) rDNA. Pseudo-nitzschia species identification was also assessed by the construction of ITS1 clone libraries and using automated ribosomal intergenic spacer analysis (ARISA) for environmental samples collected during the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), conducted in close proximity to OSP in July of 2002. Based on ITS1 sequences, the presence of P. granii, P. heimii, P. cf. turgidula, and at least five other putative, unidentified Pseudo-nitzschia ITS1 variants was confirmed within iron-enriched phytoplankton assemblages at OSP. None of the oceanic isolates produced detectable levels of particulate domoic acid (DA) when in prolonged stationary phase due to silicic acid starvation. The lack of detectable concentrations of DA suggests that either these strains produce very little or no toxin, or that the physiological conditions required to promote particulate DA production were not met and thus differ from their coastal, toxigenic congeners.
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: Adrian
authors.initials: A
authors.lastname: Marchetti
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Lundholm
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kotaki
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Hubbard
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Harrison
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, 1353 Copenhagen K, DenmarkSchool of Fisheries Sciences, Kitasato University, Sanriku, Ofunato 022-0101, JapanSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USAAtmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Clearwater Bay, Hong KongSchool of Oceanography, University of Washington, Box 357940, Seattle, Washington 98195, USA.
authors.forename: E
authors.initials: E
authors.lastname: Virginia Armbrust
keywords: ARISA; HNLC; ITS1; NE subarctic Pacific; Pseudo-nitzschia; SERIES; domoic acid; oceanic diatoms