A field study in support of the monitoring of priority substances in German freshwater fish: derivation of fillet-to-whole fish conversion factors

Environmental Sciences Europe

Table 2 Comparison of mercury concentrations of fish: all fish (aged < 10 years) vs. fish in the age-window recommended for monitoring (3–4 years, for roach 3–5 years; [7])

Age < 10 years	Hg fillet (µg kg⁻¹ ww)	Hg whole fish (µg kg⁻¹ ww)	Age 3–4/5 years^a	Hg fillet (µg kg⁻¹ ww)	Hg whole fish (µg kg⁻¹ ww)
Chub (n = 42)	74 ± 28	54 ± 18	Chub (n = 23)	62 ± 21	47 ± 12
Roach (n = 123)	49 ± 40	38 ± 30	Roach (n = 80)	45 ± 32	36 ± 26
Bream (n = 38)	30 ± 30	24 ± 24	Bream (n = 2)	58/5^b	50/4^b
Whitefish (n = 20)	87 ± 25	72 ± 19	Whitefish (n = 13)	81 ± 14	68 ± 12
Perch (n = 117)	72 ± 40	54 ± 28	Perch (n = 67)	70 ± 37	53 ± 26
All species (n = 340)	60 ± 40	46 ± 29	All species (n = 185)	58 ± 34	46 ± 26

Data are given as µg kg⁻¹ ww for fillet and whole fish samples of fish species from all sites (Elbe fish with high mercury concentrations identified as outliers were removed)
^aRoach 3–5 years, other fish species 3–4 years
^bBream from Elbe River/Baltic Sea lagoon