Table 4.

Comparison of 4-d acute LC50 values for white sturgeon (Acipenser transmontanus) to copper at various life stages

Reference	Life stage (dph)	Reported 96-h LC50 (µg Cu/L)	BLM-adjusted LC50 to USEPA standard water (µg Cu/L)a	BLM-adjusted FAV based on test water chemistry (µg Cu/L)b
The present study	2	>23.6	>16.2	7.9
Wang et al. 15	2	8.06	4.9	7.7
Vardy et al. 12c	8	22	5.3	19.4
M. Hecker, University of Saskatchewan, Saskatoon, Saskatchewon, Canada, personal communication	8	17.2
Entrix and U of S 47	8–10	30
Vardy et al. 12c	15	10	2.9	16
The present study	16d	7.1	4.4	7.6
Little et al. 11	26	4.5	2.2d
Little et al. 11	27	6.8	8.2
The present study	30	16.4	11.8	7
Little et al. 11	38	4.1	2.3d
M. Hecker, University of Saskatchewan, Saskatoon, Saskatchewon, Canada, personal communication	40	11.7
Vardy et al. 12c	40	9	2.4	17.1
Little et al. 11	40	4.7	5.5
The present study	44	>50	>34.1	7
Vardy et al. 12c	45	17	6.8	11.6
The present study	61	<90	<56	7
The present study	72	74	51.3	6.4
The present study	89	90	62.9	6.4
Vardy et al. 12c	100	54	16.1	17.1

^a For BLM-normalized LC50s, the BLM was used to extrapolate the actual LC50s to those expected for the BLM-standard water conditions, which is a moderately-hard water with pH of 7.5 and 0.5 mg/L DOC, following the approach used by USEPA ³⁰. The FAV for BLM-standard water is 4.67 µg/L ³⁰.

^b USEPA ³⁰ FAV, calculated for the individual measured test water chemistries.

^c Toxicity data for copper reported in Vardy et al. ¹² were normalized using BLM based on moderately hard reconstituted water (hardness 85 mg/L, dissolved organic carbon 0.5 mg/L).

^d Control survival for the 16 dph test was less than 90 percent, thus the EC50 calculation is not definitive.

^e Value is at or below the USEPA ³⁰ WQC for copper CMC = 2.3 µg/L.

LC50 = median lethal concentration; dph = days posthach; BLM = biotic ligand model; FAV = final acute value; USEPA = US Environmental Protection Agency; WQC = water-quality criteria.