An approach for measuring the 129I/127I ratio in fish samples

The methodology was then applied to obtain the 129I/127I ratio of marine fish samples collected from the Western Pacific Ocean as (0.63-1.2) × 10−10. These values were similar to the ratio for the surface seawater collected at the same station, 0.4 × 10−10. The 129I/127I ratio of IAEA-414, which was a mix of fish from the Irish Sea and the North Sea, was also measured and determined as 1.82 × 10−7. Consequently, fish from the Western Pacific Ocean and the North Sea were distinguished by their 129I/127I ratios. The 129I/127I ratio is thus a direct indicator of the area of habitat of fish.