Table 2.
Comparison of slopes of nutrient metal to phosphate plots for station H-77 (Bruland, 1980) in the northeast Pacific with metal:P ratios in net plankton (Martin et al., 1976) and metal:C ratios in cultured marine algae.
| Metal | Depth range (m) | P range (μM) | M vs P slope (mmol mol−1) | Intercept (nM) | R2 (n) | M:P of net plankton (mmol mol−1) | M:C from slopes* (μmol mol−1) | M:C in cultured algae |
|---|---|---|---|---|---|---|---|---|
| Zn | 185–780 | 0.81–3.27 | 2.32 ± 0.06 | −1.62 ± 0.14 | 0.998 (4) | 1.9 ± 1.6 | 22.2 ± 0.6 | |
| 0–185 | 0.06–0.81 | 0.33 ± 0.04 | 0.07 ± 0.02 | 0.987 (3) | 3.1 ± 0.4 | 3.7(2.2–5.5)† | ||
| Cd | 75–975 | 0.18–3.33 | 0.32 ± 0.01 | −0.06 ± 0.03 | 0.994 (6) | 0.43 ± 0.14 | 3.0 ± 0.1 | 2.5–4.1‡ |
| Ni | 0–780 | 0.06–3.27 | 1.93 ± 0.10 | 2.36 ± 0.20 | 0.989 (6) | 0.47 ± 0.26 | 18.2 ± 1.0 | |
| Cu | 0–975 | 0.06–3.33 | 0.44 ± 0.02 | 0.57 ± 0.04 | 0.992 (7) | 0.41 ± 0.13 | 4.2 ± 0.2 | 4.4 ± 0.6§ |
*Based on a C:P for marine plankton of 106 (Redfield et al., 1963).
†Mean and range based on mean and range of [Zn′] computed from the Zn chelation data of Bruland(1989; see Table 1) and the Zn:C vs [Zn′] relationship for the oceanic diatom Thalassiosira oceanica (Figure 5).
§Based on the mean Cu:C in the diatoms T. oceanica and T. pseudonana, and the coccolithophore Emiliana huxleyi at the mean log [Cu′] in northeast Pacific ocean water (−11.8, see Table 1; Sunda and Huntsman, 1995c).