Acute and chronic sensitivity of white sturgeon (<i>Acipenser transmontanus</i>) and rainbow trout (<i>Oncorhynchus mykiss</i>) to cadmium, copper, lead, or zinc in laboratory water-only exposures

Abstract

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.

Chronic sensitivity of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss) to cadmium, copper, lead, or zinc in laboratory water‐only exposures

“…However, acute effects for cadmium, copper, and zinc were observed during the first 4 d of the C2 exposures started with juvenile trout. Survival of the juvenile trout in the C2 exposures was significantly reduced relative to the controls at the medium or high concentrations of cadmium, copper, and zinc (see Ingersoll and Mebane ). The 4‐d LC50 values for cadmium (>12 µg Cd/L) or zinc (>748 µg Zn/L) for the larval trout in the C1 exposures were greater than the 4‐d LC50s (5.14 µg Cd/L) or zinc (267 µg Zn/L) for juvenile trout in the C2 exposures by a factor of more than 2, whereas the 4‐d LC50s for copper were similar between the larval (60 µg Cu/L) and juvenile (63 µg Cu/L) stages.…”

“…The number of the control replicates in the zinc exposure was reduced to 3 because of limited number of extra surviving fish from the other control replicate chambers in the diluter for the zinc test. From the thinning day to the end of the 53‐d exposures, the survival and growth of the sturgeon in the pseudoreplicates were not substantially or consistently different from the survival and growth in the true replicates (see Ingersoll and Mebane ). Therefore, the pseudoreplicates were included for the further data analysis in the 53‐d CC exposures with sturgeon.…”

“…Chronic EC20s are summarized in Table . Additional effect concentrations, such as 10% effect concentrations, no‐observed‐effect concentrations, and lowest‐observed‐effect concentrations, are reported in Ingersoll and Mebane . Because of the low control survival by the end of the 25‐d C1 exposures, LC20s for the C1 exposures were estimated based on the survival on test day 14 when mean control survival was high, ranging from 99% to 100% (Table ), and met the test acceptability criteria of ≥80% control survival (Supplemental Data, Table S1).…”

“…Method detection limits for DOC ranged from approximately 0.05 mg/L to 0.2 mg/L, depending on analysis batch. Relative high variability in DOC measurements was observed within and across collection dates in the 2010 sturgeon and trout tests . The most reliable measurements of DOC ranged from approximately 0.3 mg/L to 0.5 mg/L, and there were no obvious upward or downward trends in DOC concentrations over the duration of the tests.…”

“…Two companion studies were conducted in 2010 to evaluate the acute toxicity of cadmium, copper, or zinc to white sturgeon and rainbow trout at various life stages and the toxicity of whole sediments from the Upper Columbia River to white sturgeon (M. Hecker, University of Saskatchewan, Saskatoon, Canada, personal communication). A report by Ingersoll and Mebane provided additional supporting information regarding test methods and toxicity or chemistry data for the present study. The results of the present study are part of a baseline ecological risk assessment being conducted at the Upper Columbia River in eastern Washington State.…”