Table 3.
Zinc LC50 or EC50 4-d acute value estimates for white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss)
| Species | Life stage (dph) | Average fish weighta (g) | Average fish lengtha (cm) | LC50 (µg/L), mortality onlyb | EC50 (µg/L), mortality + LOE + immobilizationb> | BLM-normalizedc LC50 or EC50 (µg/L) |
|---|---|---|---|---|---|---|
| Sturgeon | ||||||
| 2d | 0.04 (0.0) | NM | >634 | 146.7 (134.4–160.1) | >928 / 209 | |
| 16e | 0.13 (0.17) | 21 (0.67) | >1575 | >1575 | >2161 | |
| 30 | 0.17 (0.04) | 30.6 (2.72) | 3109 (2499–3868) | 3109 (2499–3868) | 3793 | |
| 44 | 0.6 (0.15) | 49.3 (5.29) | >2610 | >2610 | >3088 | |
| 61 | 1.16 (0.41) | 62.4 (8.47) | <253 | <253 | <292 | |
| 72 | 2.02 (0.80) | 77.7 (11.08) | <391 | <391 | <450 | |
| 89 | 3.73 (1.06) | 97.57 (10.48) | <9330 | <586 | <10 487 / <657 | |
| Trout | ||||||
| 1 | 0.08 (0.12) | 14.3 (1.74) | >571 | >571 | >726 | |
| 18 | 0.10 (0.02) | 24.33 (1.06) | 253.2 (223.3–287.1) | 253.2 (223.3–287.1) | 306 | |
| 32 | 0.12 (0.03) | 26.67 (1.97) | 448.9 (381.3–528.7) | 448.9 (381.3–528.7) | 540 | |
| 46 | 0.22 (0.06) | 31.3 (3.02) | 282 (232.8–348.8) | 267.2 (220.9–323.2) | 409 / 389 | |
| 60 | 0.32 (0.07) | 36.8 (3.16) | 268.5 (206.7–348.8) | 223.8 (177.0–282.0) | 318 / 265 | |
| 74 | 0.39 (0.13) | 39.8 (3.55) | 345.9 (296.5–403.5) | 345.9 (296.5–403.5) | 436 | |
| 95d | 0.70 (0.18) | 45.43 (3.89) | 227.9 (200.5–259.2) | 227.9 (200.5–259.2) | 254 | |
Values in parentheses for average fish weight and average fish length (n = 10 for white sturgeon; n = 30 for rainbow trout) are the standard deviation.
Values in parentheses for LC50s and EC50s are the 95% confidence intervals.
USEPA 54 hardness-based FAV is 204 mg/L for moderately hard water, and DeForest and Van Genderen 31 revised BLM FAV is 261 µg/L for moderately hard water.
The most sensitive life stage for the respective species.
Control survival for the 16 dph test was less than 90 percent, thus the EC50 calculation is not definitive.
LC50 = median lethal concentration; EC50 = median effective concentration; dph = days posthach; LOE = loss of equilibrium; BLM = biotic ligand model; FAV = final acute value; NM = not measured; USEPA = US Environmental Protection Agency; AWQC = acute water-quality criteria.