Effect of Different Derivatization Protocols on the Calculation of Trophic Position Using Amino Acids Compound-Specific Stable Isotopes

Stephane Martinez, Maya Lalzar, Eli Shemesh, Shai Einbinder, Beverly Goodman Tchernov, Dan Tchernov

Research output: Contribution to journalArticlepeer-review

Abstract

Amino acids compound-specific nitrogen stable isotope analysis (AA-CSIA) is an emerging tool in ecology for understanding trophic system dynamics. While it has been successfully used for several independent studies across a range of environments and study locations, researchers have encountered calculation issues for determining trophic position values. Most studies introduce modifications to the constants of trophic position equation calculations, but then fail to account for the equation variations when comparing across separate research studies. The broad acceptance of this approach is anchored in an underlying presumption that no addition of the exogenous nitrogen atom occurs in the different methods; and therefore, such variations should not affect the outcome. In this paper, we evaluate the use of the EZfaast amino acid derivatization kit (chloroformate) and compare it to the isotopic results of two other derivatization methods. We highlight new considerations for working with AA-CSIA that might account for some of the variations in the results and lead researchers to modify constants in the equation. This study concludes that developing unique constants per derivatization method is required to have more accurate cross-study comparisons of trophic positions.

Original languageEnglish
Article number561568
JournalFrontiers in Marine Science
Volume7
DOIs
StatePublished - 15 Dec 2020

Bibliographical note

Publisher Copyright:
© Copyright © 2020 Martinez, Lalzar, Shemesh, Einbinder, Goodman Tchernov and Tchernov.

Keywords

  • AA-CSIA
  • calibration
  • eastern Mediterranean Sea
  • food web
  • nitrogen isotopic composition
  • trophic discrimination factor

ASJC Scopus subject areas

  • Oceanography
  • Global and Planetary Change
  • Aquatic Science
  • Water Science and Technology
  • Environmental Science (miscellaneous)
  • Ocean Engineering

Fingerprint

Dive into the research topics of 'Effect of Different Derivatization Protocols on the Calculation of Trophic Position Using Amino Acids Compound-Specific Stable Isotopes'. Together they form a unique fingerprint.

Cite this