The main elements used in isotope ecology are carbon, nitrogen, oxygen, hydrogen and sulfur.Analysis of the ratio of Stable isotopes have become a popular method for understanding aquatic ecosystems because they can help scientists in understanding source links and process information in marine food webs.This can be applied to a food web to make it possible to draw direct inferences regarding diet, trophic level, and subsistence.Variations in isotope ratios from isotopic fractionation are measured using mass spectrometry, which separates the different isotopes of an element on the basis of their mass-to-charge ratio.Annually laminated (varved) sediments from the River Ångermanälven, mid-central Sweden, have been used to construct an annual 2000-year long record of varve thickness.
Bone is continually remodelled throughout the lifetime of an individual.
Particularly in the Bronze Age Mediterranean, lead isotope analysis has been a useful tool for determining the sources of metals and an important indicator of trade patterns.
Interpretation of lead isotope data is, however, often contentious and faces numerous instrumental and methodological challenges.
Potential C3 food sources include rice, tubers, fruits, nuts and many vegetables, while C4 food sources include millet and sugar cane.
This process ends with the organism's death, from this point on isotopes no longer accumulate in the body, but do undergo degradation.