Stable isotope analysis as a tool for determining seafood provenance

Aim: To determine if stable isotope analysis is a viable tool for authenticating the geographical origin of seafood purchased from the market. The carbon and nitrogen isotope values of samples were analysed to determine if they differ according to their source.

Methodology: One set of barramundi samples were purchased from three different markets and another set was obtained directly from a farm. Two sets of tiger prawn samples were obtained from the same markets as the barramundi. These samples were then analysed using isotope ratio mass spectrometry to determine their carbon and nitrogen isotopic values.

Results: The barramundi samples showed significant differences between sources in both the δ¹³C (< 0.05) and δ¹⁵N (< 0.05) values. Similarly, the tiger prawn samples also showed significant differences between sources in the δ¹³C (< 0.05) and δ¹⁵N (p-value < 0.05) values.

Interpretation: This pilot study successfully distinguished between barramundi samples and tiger prawns from different geographical locations. We recommend that further studies be conducted with a higher number of samples, and multiple sites from different geographic regions, and to account for factors influencing the δ¹³C and δ¹⁵N values. This study highlights the potential of isotopic analysis as a tool for policy makers and regulatory bodies to verify seafood provenance and enforce industry compliance for source labelling of seafood products.