Laboratory experiments to determine trophic enrichment factors of stables isotope and fatty acid biomarkers in the blue crab, Callinectes sapidus

Stable isotope (SI) and fatty acid (FA) biomarkers provide new ways to understand predator-prey interactions. In particular, quantitative inference about the strength of feeding links can be achieved with biomarker mixing models, whose accurate application requires trophic enrichment factors (TEF) accounting for metabolism, deposition, or synthesis (also known as a “discrimination factors” or “calibration coefficients” for SI and FA, respectively). Nevertheless, many applications of mixing models do not use TEFs developed for the particular predator or conditions of interest (e.g., life stage, diet quality). We conducted a 12-week laboratory experiment to quantify SI and FA TEFs for the ecologically and economically important Blue crab, Callinectes sapidus.