Amino acid d13C dataset for nearshore marine primary producers

Carbon isotope fingerprinting, or multivariate analysis using δ13C values of individual compounds, is a powerful tool in ecological studies, particularly measurements of essential amino acids (EAA δ13C). Despite the widespread application of this technique, there has been little methodological validation to determine (1) whether multivariate EAA δ13C signatures (fingerprints) of primary producer groups vary across space and time, and (2) what biochemical mechanisms drive these patterns.
Here, we evaluate the spatiotemporal consistency in EAA δ13C fingerprints among nearshore primary producers: Chlorophyta (Ulva sp.), Ochrophyta (kelps), particulate organic matter (POM) and phytoplankton, and Rhodophyta. We analyzed 135 samples from 14 genera collected in Alaska, California, and Chile. The collections included historical museum samples (1896-1980 CE) of the giant kelp, Macrocystis pyrifera. We employed canonical analysis of principal coordinates and generalized linear models (GLMs) to re...