Table 2.
Pseudo-nitzschia species and toxin levels for samples from oceanic Pacific locations in this study
| Cruise/station | Location | Domoic acid, pg·cell−1 | Sample age at time of analysis | Dominant Pseudo-nitzschia species |
| GOA /16 | NE Subarctic Pacific | b.d.l. | 1 mo | P. fraudulenta |
| P. pseudodelicatissima | ||||
| GOA /28 | NE Subarctic Pacific | b.d.l. | 1 mo | P. heimii |
| P. cf granii* | ||||
| P. turgidula*,† | ||||
| GOA /53 | NE Subarctic Pacific | 0.003 | 1 mo | P. turgidula*,† |
| P. pseudodelicatissima | ||||
| P. inflatula | ||||
| GOA /55 | NE Subarctic Pacific | 0.0004 | 1 mo | P. turgidula*,† |
| GOA /58 | NE Subarctic Pacific | 0.0003 | 1 mo | P. pseudodelicatissima |
| P. turgidula*,† | ||||
| GOA /62 | NE Subarctic Pacific | b.d.l. | 1 mo | P.cf lineola† |
| VERTIGO K2 /4 | NW Subarctic Pacific | 0.84 | 2 y | P. turgidula*,† |
| VERTIGO K2 /76 | NW Subarctic Pacific | 1.9 | 2 y | P. turgidula*,† |
| IronEx II /240 | Equatorial Pacific | 0.02 | 12 y | P. inflatula |
| P. delicatissima | ||||
| P. heimii | ||||
| P. cuspidata | ||||
| IronEx II /331 | Equatorial Pacific | 0.05 | 12 y | P. lineola† |
| P. roundii | ||||
| P. turgidula*,† | ||||
| P. heimii | ||||
| SOFeX /36 (South) | Antarctic Pacific | 1.0 | 4 y | P. lineola |
| P. granii*,† | ||||
| P. pseudodelicatissima | ||||
| P. cf turgiduloides | ||||
| SOFeX /40 (South) | Antarctic Pacific | 0.69 | 4 y | Rare overall |
| Mostly P. lineola† |
*Species associated with DA production from grow outs of oceanic phytoplankton samples from station PAPA in the NE Subarctic Pacific and/or from in situ water samples at that station (16).
†Toxin observed from in situ water samples from oceanic stations in the present study.
Species identifications using electron microscopy (SEM and TEM) were made on samples from 12 sites based on the availability of net tow material and corresponding DA samples. The “Domoic acid, pg·cell-1” column presents data showing the average cell quota for the Pseudo-nitzschia in that sample. The designation “b.d.l.” indicates DA was below the detection limit, which could reflect either the sparcity of the cells in the water or the possibility that many other species were present in the sample, hence making the contribution of DA, even in cells with reasonably high DA levels, a small fraction of the total material in that sample and, thus, below detection limit. The “sample age at time of analysis” is the time from collecting the sample at sea until the time the sample was analyzed. “Dominant Pseudo-nitzschia species” were identified from aliquots of the net tows using electron microscopy (Table S2). At 5 of the 12 stations, only 1 species was found and, thus, the DA cell quotas could be assigned to those species, whereas in the 7 other samples 2–4 species were evident and, thus, the listed pg·cell−1 reflects an average for the mix of those species.