The acute toxicity of cadmium, copper, and zinc to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) were determined for 7 developmental life stages in flow-through water-only exposures. Metal toxicity varied by species and by life stage. Rainbow trout were more sensitive to cadmium than white sturgeon across all life stages, with median effect concentrations (hardness-normalized EC50s) ranging from 1.47 µg Cd/L to 2.62 µg Cd/L with sensitivity remaining consistent during later stages of development. Rainbow trout at 46 d posthatch (dph) ranked at the 2nd percentile of a compiled database for Cd species sensitivity distribution with an EC50 of 1.46 µg Cd/L and 72 dph sturgeon ranked at the 19th percentile (EC50 of 3.02 µg Cd/L). White sturgeon were more sensitive to copper than rainbow trout in 5 of the 7 life stages tested with biotic ligand model (BLM)-normalized EC50s ranging from 1.51 µg Cu/L to 21.9 µg Cu/L. In turn, rainbow trout at 74 dph and 95 dph were more sensitive to copper than white sturgeon at 72 dph and 89 dph, indicating sturgeon become more tolerant in older life stages, whereas older trout become more sensitive to copper exposure. White sturgeon at 2 dph, 16 dph, and 30 dph ranked in the lower percentiles of a compiled database for copper species sensitivity distribution, ranking at the 3rd (2 dph), 5th (16 dph), and 10th (30 dph) percentiles. White sturgeon were more sensitive to zinc than rainbow trout for 1 out of 7 life stages tested (2 dph with an biotic ligand model–normalized EC50 of 209 µg Zn/L) and ranked in the 1st percentile of a compiled database for zinc species sensitivity distribution. Environ Toxicol Chem 2014;33:2259–2272. © 2014. The Authors. This article is a US government work and, as such, is in the public domain in the United States of America. Environmental Toxicology and Chemistry published byWiley Periodicals, Inc. on behalf of SETAC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

The acute toxicity of cadmium (Cd), copper (Cu), and zinc (Zn) to white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) was determined for seven developmental early life stages in flow-through wateronly exposures. Test waters consisted of five concentrations of each metal and a control. Nominal concentrations ranged from 0.01-600 micrograms per liter (µg/L) for cadmium, 0.1-300 µg/L for copper, and 0.4-10,000 µg/L for zinc, with higher exposure concentrations tested with older life stages. Exposures were performed in a water with a hardness of about 100 milligram per liters (mg/L) (as calcium chloride (CaCO 3)) and dissolved organic carbon of about 0.4 mg/L. Sturgeon were tested at 2, 16, 30, 44, 61, 72, and 89 dayspost-hatch (dph) and trout were tested at 1, 18, 32, 46, 60, 74, and 95 dph. Metal toxicity varied by species and by life stage. The 50-percent lethal concentrations (LC50) were based on mortality; whereas 50-percent effect concentrations (EC50s) were based on mortality, loss of equilibrium, and immobilization. The EC50s were used in comparisons with nationally recommended water-quality criteria (WQC) or to Washington State water-quality standards (WQS). Test acceptability requirement of greater than or equal to (≥)90 percent control survival was achieved in all exposures with the exception of 16-dph sturgeon exposures where control survival was 65 to 80 percent (hence, the EC50 for 16-dph sturgeon was classified as nondefinitive effect concentrations); however, despite the low control survival, the reductions in the survival of exposed 16-dph sturgeon were concentration dependent. Rainbow trout were more sensitive to cadmium than sturgeon across all life stages with LC50s ranging from 2.77 to greater than (>)49.4 micrograms cadmium per liter (µg Cd/L) with sensitivity remaining consistent during later stages of development (18-95 dph). Sturgeon LC50s for cadmium ranged from >47.2 to >355 µg Cd/L with sensitivity increasing during later stages of development (30-89 dph). The LC50 endpoint 6 Acute and Chronic Sensitivity of White Sturgeon and Rainbow Trout to Cadmium, Copper, Lead, or Zinc State WQS. For sturgeon aged 2 dph, the EC50 was below the WQC for copper and was below the Washington State WQS for all life stages tested. Although classified a nondefinitive effect concentration because of elevated 4-d control mortality, the EC50 for sturgeon at age 16 dph also fell below the WQC and Washington State WQS for copper. Sturgeon at 2 dph was the only life stage where the EC50 essentially was equal to the WQC and fell below the Washington State WQS for zinc. Results of this study will be submitted for consideration as part of a baseline ecological risk assessment being performed at the upper Columbia River in eastern Washington State.

Commercial formulations of pesticides contain both active and other ingredients. In some instances, the other ingredients have detrimental effects on nontarget species. Other factors such as UV radiation and predator cues have been shown to modify the toxicity of pesticides. In a laboratory study we compared the effects of technical-grade active ingredients to commercial formulations of seven common pesticides in the presence or absence of UV radiation on the survival of Rana clamitans (green frog) tadpoles over 96 h. We found a significant difference in the survival of tadpoles in technical-grade active ingredients versus commercial formulations in all of the pesticides tested. We also found that either the presence or the absence of UV radiation affected the survival of tadpoles in five of the seven pesticides tested. These results suggest that there is a need to test the effects of both active ingredients and commercial formulations of pesticides and, also, to include relevant abiotic factors like UV radiation treatments in the testing of pesticides because they can have a dramatic impact on the toxicity of some chemicals.

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