Global Trophic Position Comparison of Two Dominant Mesopelagic Fish Families (Myctophidae, Stomiidae) Using Amino Acid Nitrogen Isotopic Analyses

• DOI: 10.1371/journal.pone.0050133
• Publication Date: 2012-11-28T21:56:04Z
• Authors: C. Anela Choy; Peter C. Davison; Jeffrey C. Drazen; Adrian Flynn; Elizabeth J. Gier; Joel C. Hoffman; Jennifer P. McCla...; Todd W. Miller; Brian N. Popp; Steve W. Ross; Tracey T. Sutton
• Keywords: Mesopelagic zone; Isotope Analysis; Biogeochemistry; Isotopes of nitrogen; Trophic state index

The δ15N values of organisms are commonly used across diverse ecosystems to estimate trophic position and infer connectivity. We undertook a novel cross-basin comparison in two ecologically well-characterized different groups dominant mid-water fish consumers using amino acid nitrogen isotope compositions. found that positions estimated from the individual acids nearly uniform within both families these fishes five global regions despite great variability bulk tissue values. Regional differences phenylalanine confirmed reflect region-specific water mass biogeochemistry controlling at base food web. Trophic calculated isotopic analyses (AA-TP) for lanternfishes (family Myctophidae) (AA-TP ∼2.9) largely align with expectations stomach content studies (TP ∼3.2), while AA-TPs dragonfishes Stomiidae) ∼3.2) were lower than TPs derived (TP∼4.1). demonstrate analysis can overcome shortcomings biogeochemically distinct systems provide globally comparative information regarding marine web structure.