Trace Element Concentrations in Bearded Seals (Erignathus barbatus) Near Red Dog Mine Compared to Other Locations in Alaska

Table 2

Statistical comparisons of trace element concentrations in bearded seal liver tissue between Red Dog Mine port site (RDM) and reference sites. No statistical tests were conducted when trace elements were detected in less than 50% of samples. ANCOVA was used to control for possible age effects when the nonparametric Mann-Whitney test identified differences in trace metals concentrations between RDM and reference samples. Trace elements detected in more than 50% of samples that Mann-Whitney tests identified as statistically different between RDM and reference sites are in bold.

	Minimum detection limit	Proportion of samples above detection limit
Element	(𝜇g/g wet weight)	RDM (n = 9)	Reference sites (n = 15)	Above threshold for statistical analyses?	Mann-Whitney P	Significant age effect?	ANCOVA P
Al	1.78	0.22	0.33	No
As	0.19	1.00	0.96	Yes	.03	No	—
B	0.62	0.00	0.08	No
Ba	0.15	0.11	0.04	No
Be	0.03	0.00	0.00	No
Cd	0.03	1.00	0.88	Yes	.24	Yes	.53
Cr	0.16	0.00	0.13	No
Cu	0.09	1.00	1.00	Yes	<.01	No	—
Fe	0.89	1.00	1.00	Yes	.5	No	—
Hg	0.3	1.00	1.00	Yes	.04	Yes	.54
Mg	1.39	1.00	1.00	Yes	.43	No	—
Mn	0.16	1.00	1.00	Yes	.1	Yes	.28
Mo	0.62	0.22	0.17	No
Ni	0.16	0.11	0.04	No
Pb	0.09	0.00	0.04	No
Se	1.19	1.00	1.00	Yes	.01	Yes	.59
Sr	0.06	1.00	1.00	Yes	.46	No
V	0.16	0.89	0.63	Yes	.06	Yes	.06
Zn	0.16	1.00	1.00	Yes	.28	No