A Perspective on the Toxicity of Petrogenic PAHs to Developing Fish Embryos Related to Environmental Chemistry

Figures & data

Table 1 Phytane concentrations in oiled-rock column effluent water by day and treatment.

	Aqueous total PAH conc. (μ g/l)
Day	Control 0.02	0.94	3.70	16.52	44.67
0	< 0.001 ^a	< 0.001 ^a	< 0.001 ^a	< 0.001 ^a	0.009 ^b
15	< 0.001 ^a	< 0.001 ^a	0.019 ^b	0.013 ^b
28	< 0.001 ^a	< 0.001 ^a	< 0.001 ^a	0.006 ^b	0.017 ^b
54	< 0.001 ^a	< 0.001 ^b	0.014 ^b	< 0.001 ^a	0.012 ^b
76	< 0.001 ^a	< 0.001 ^a	0.228*	0.022 ^b	0.039 ^b
184	< 0.001 ^a	< 0.001 ^a	0.005 ^b	< 0.001 ^a	0.008 ^b
Initial aqueous total PAH concentrations were as indicated (top row). An asterisk identifies the only water sample where phytane was within the range of quantification; ,

Table 2 Phytane concentrations in pink salmon eggs and alevins by day and treatment.

	Aqueous total PAH conc. (μ g/l)
Day	0.02	0.94	3.7	16.5	44.7
1	36.5 ^a	—	—	—	—
15	27.6 ^b	< 1 ^a	< 1 ^a	< 1 ^b	< 1 ^a
27	< 1–30.5 ^b	< 1 ^a	< 1 ^a	< 1–41.3 ^b	< 1 ^a
53	< 1 ^b	< 1 ^b	< 1 ^c	< 1 ^b	< 1 ^b
75	< 1 ^b	< 1 ^b	< 1 ^b	< 1 ^b	< 1 ^a
183	< 1 ^a	< 1 ^a	< 1 ^a	< 1 ^a	< 1 ^a
Tabled values are total PAH concentrations in tissue (ng/g wet weight) for eggs (days 1 to 75) and alevins (day 183) exposed to oiled rock column effluent (days 0 through 53) or in contact with effluent water and oiled rock thereafter. Initial aqueous total PAH concentrations were as indicated (top row). Number of samples measured were , or

Table 3 Microbial growth in oiled-rock column assays and lowest adverse effective concentrations (LOECs).

Study	Species	Median rock diameter (mm)	Flow (ml/min)	Exposure time (d)	Delta ^a (%)	LC50 (μ g/l)	LOEC (μ g/l)	Metric
Marty et al. (1997)	pink salmon	50.8	125	215	25.7	39 (37–41)	4.4	acites (edema), premature emergence, increased gonadal cell apoptosis
Heintz et al. (1999)	pink salmon	25.4	150	241	6.8	43 (38–47)	17.6	embryo mortality
Heintz et al. (2000)	pink salmon	25.4	150	206	0.4	ne	5.4	decreased marine survival
Carls et al. (2005)	pink salmon	5.4	1600	195	–1.0	48 (43–52)	0.9	reduced growth
Carls et al. (1999)	Pacific herring	5.2	7000	16	–1.7	53 (45–62)	9.1	yolk-sac edema
Median lethal concentrations (LC50s) include 95% confidence intervals in parentheses; ne = not estimable (this experiment was not designed to measure mortality). Species are pink salmon (Oncorhynchus gorbuscha) and Pacific herring (Clupea pallasi).
Values of delta ≤ 0 were interpreted as evidence of no microbial growth. Increasingly positive values of delta indicated increased branched alkane concentrations relative to other alkanes and were interpreted as evidence of enhanced microbial growth.

Table 4 Estimated toxic units (TUs) in the highest oil treatment over time (case-history study).

Day	TU at 10 μg/l	TU variable conc.	Observed total PAH conc. (μ g/l)
0	0.34	1.54	44.67
28	1.24	0.22	1.77
54	2.07	0.14	0.69
76	2.22	0.08	0.38
Estimated TUs at a constant total PAH concentration (10 μg/l) are compared to estimated TUs under the variable, exponentially declining total PAH concentrations reported in the right-hand column. Data from Carls et al. (2005).

Figure 1 Comparison of change in embryo response (left panels) and median effective concentrations (EC50s; right panels) from less weathered oil (open bars) to more weathered oil (solid bars) and the ratios between these (bottom panels). Illustrated measures are yolk-sac edema (y. edema), spinal abnormalities (spine), swimming incompetence (swim), and jaw malformations (jaw) by treatment (3 or 4, the highest two doses in the experiment). Data from Carls et al. (1999).

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