Table 1.
Pseudo-nitzschia abundance, DA cell quotas, and estimated DA concentrations in the waters of six oceanic regions of the Pacific
| Cruise |
||||||
| Measurement | Gulf of Alaska | VERTIGO ALOHA | VERTIGO K2 | IronEx II | SOFeX (N) | SOFeX (S) |
| Location (no. of stations sampled) | NE Subarctic Pacific (18) | Subtropical Pacific (7) | NW Subarctic Pacific (4) | Equatorial Pacific (2) | Sub-Antarctic Pacific (1) | Antarctic Pacific (3) |
| Pseudo-nitzschia abundance, cells·L−1 | 8.6 × 103 ± 1.3 × 104 (n = 14) | 9.8 × 101 ± 2.5 × 102 (n = 14) | 3.4 × 103 ± 3.7 × 103 (n = 11) | 1.3 × 106 ± 1.3 × 106 (n = 2) | 3.7 × 105 (n = 1) | 7.5 × 104 ± 1.3 × 106 (n = 3) |
| Range | b.d.l./4.2 × 104 | b.d.l./9.4 × 102 | 7.6 × 100 to 1.3 × 104 | 3.5 × 105 to 2.3 × 106 | Not applicable | 2.0 × 103 to 2.2 × 105 |
| DA cell quota pg·cell−1 | 0.03 ± 0.07 (n = 6) | m.d. | 0.9 ± 0.7 (n = 4) | 0.04 ± 0.02 (n = 2) | m.d. | 0.85 ± 0.23 (n = 2) |
| Range | 0.0003–0.16 | m.d. | 0.4–1.9 | 0.02–0.05 | m.d. | 0.69–1.0 |
| DA in water range, ng·L−1 | 0.0002–1.4 | m.d. | 1.7–3.6 | 18–45 | m.d. | 2.0–220 |
Average Pseudo-nitzschia abundances, cellular domoic acid (DA) quotas, and water levels of DA are presented here for 35 oceanic stations sampled over 12 y on five different research cruises. Ranges are also presented. 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 the detection limit. Missing data are indicated by “m.d.” Cell quota averages are based on samples where DA was detected (i.e., measurements that were below our detections limits were not included in the computation of the average) (Table S1, legend). It was assumed all species/cells have equal DA levels. DA in the water was then computed by multiplying the cell abundance by the DA cell quotas (at stations where DA was detected). Values represent means ± 1 SD and sample replicates (n) appear in parentheses. Of 35 stations sampled, Pseudo-nitzschia was present at 34 stations. Samples from 26 stations were analyzed for DA with detectable levels found at 14 stations (see Table S1 for complete data set).