Australian farmed Yellowtail Kingfish (Seriola lalandi) and Mulloway (Argyrosomus hololepidotus): Residues of metallic, agricultural and veterinary chemicals, dioxins and polychlorinated biphenyls

Abstract

Composite samples of Australian farmed Yellowtail Kingfish (Seriola lalandi) (YTKF) (n=27), Mulloway (Argyrosomus hololepidotus) (n=6) and manufactured feed (n=5) were analysed to benchmark levels of a broad range of residues and contaminants of potential public health and trade significance. A subset of these samples [YTKF (n=5), Mulloway (n=2) and feed (n=5)] was analysed for dioxins and polychlorinated biphenyls (PCBs). The mean concentration of dioxins in YTKF was 0.6pg TEQg−1 (range 0.22–0.8) and in Mulloway was 0.16pg TEQg−1 (range 0.16–0.16). The mean concentration of dioxins and dioxin-like PCBs in YTKF was 2.6pg TEQg−1 (range 1.4–3.5), while Mulloway had a mean concentration of 0.67pg TEQg−1 (range 0.57–0.76). The mean concentration of PCBs in YTKF was 21μgkg−1 (range 8.6–29) and in Mulloway was 5.4μgkg−1 (mean 4.7–6). The mean concentration of dioxin-like PCBs in YTKF was 2.1pg TEQg−1 (range 1.2–2.8) and in Mulloway was 0.51pg TEQg−1 (range 0.41–0.61). The mean mercury concentration in YTKF was 0.03mgkg−1 (range 0.02–0.05) and in Mulloway it was 0.02mgkg−1 (range 0.02–0.04). There were no detectable levels of any pesticide or antimicrobial compounds in any sample of YTKF or Mulloway. Attention is drawn to technical differences in port of entry testing programs such as sampling strategies, portion tested, laboratory methodology, residue definitions and reporting conventions that exporters’ products may be subject to. All residues and contaminants were either undetectable or present at very low levels when judged against Australian, Japanese and European Union regulatory standards (where set).