http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0028880
UCLA ion microprobe technology increases understanding of salmon populations
The UCLA ion microprobe lab collaborated with a team of fish ecologists to measure the level of sulfur isotopes in the ear bones of adult Chinook salmon. These measurements allowed them to understand which adult fish were born in hatcheries and which were part of the natural population. The natural population was thus shown to be in decline and the study highlighted the importance of considering origin when evaluating salmon population