DOI: 10.5061/dryad.g4f4qrg02
title: Data from: Spatiotemporal patterns in profiles of amino acids indicates they are unlikely singular olfactory cues underlying natal homing in migratory fishes

description: Migratory fishes are renowned for their ability to home to natal streams
 for spawning. Learned olfactory cues play a critical role in natal homing
 of Pacific salmon and other fishes, but the underlying chemical signature
 of streams remains poorly understood after decades of study. The molecules
 that convey a stream-specific odor must differ among sites but remain
 constant over time. Among leading odorant candidates are amino acids;
 however, little research has assessed the spatial and temporal variability
 of amino acid profiles in streams. Here, we report a comprehensive
 chemical study of dissolved amino acids as potential olfactory cues for
 homing by migratory fish. Specifically, we profiled amino acids in water
 from twenty-three streams in the upper Laurentian Great Lakes basin over
 two years. Using this dataset, we investigated variation in amino acid
 profiles 1) among regions and rivers within a year, 2) between years, and
 3) among sites and across the seasons of migratory and early development
 within a stream. Liquid-chromatography tandem mass spectrometry revealed
 nanomolar concentrations for most of the 20 L-amino acids measured, above
 the levels detectable by migratory fishes studied. Moreover, amino acid
 profiles were temporally stable between two years and across an annual
 season from adult spawning migration through offspring early-life
 development within a stream. However, spatial differences in amino acid
 profiles were evident primarily over large geographic distances (among
 regions) but not among tributaries within regions or among sites within a
 stream. Collectively, our results indicate dissolved amino acids may be
 consistent components of rivers’ odorant profiles but suggest additional
 molecules are likely important for natal homing of migratory fishes to
 specific spawning sites. We suggest that future studies consider the
 combined importance of amino acids and molecules from other chemical
 classes. Understanding the chemical basis of olfactory-guided natal homing
 is especially important as human activities could alter the odorant
 profiles of streams and thereby disrupt fish migrations.
description: # Data from: Spatial and temporal variability in river chemistry indicates
 amino acids profiles are unlikely singular olfactory cues underlying natal
 homing in migratory fishes ## Description of the data and file structure
 This CSV file is organized with rows representing individual water samples
 and columns representing specific measures recorded for each water sample.
 A value of 'NA' is used when measures are below the limit of
 detection. Below we list expanded titles for each variable: * River: Name
 of river where water sample was collected * Region: Region where sample
 was collected. This label is used to differentiate groups of rivers for
 statistical analyses. * State: State within the United States where sample
 was collected (i.e., LP_MI: Lower peninsula of Michigan; UP_MI: Upper
 peninsula of Michigan, WI: Wisconsin) * Sample: Sample period
 identification. This value represent the sampling time within a given year
 * Rep: Replicate number to distinguish replicate samples from the same
 sample period and sample location * Year: Year when sample was collected *
 Lon: longitude of sampling site * Lat: latitude of sampling site * Valine:
 concentration of the amino acid valine in each water sample (nM) *
 Leucine: concentration of the amino acid leucine in each water sample (nM)
 * Isoleucine: concentration of the amino acid isoleucine in each water
 sample (nM) * Alanine: concentration of the amino acid alanine in each
 water sample (nM) * Tryptophan: concentration of the amino acid tryptophan
 in each water sample (nM) * Methionine: concentration of the amino acid
 methionine in each water sample (nM) * Serine: concentration of the amino
 acid serine in each water sample (nM) * Phenylalanine: concentration of
 the amino acid phenylalanine in each water sample (nM) * Lysine:
 concentration of the amino acid lysine in each water sample (nM) *
 Histidine: concentration of the amino acid histidine in each water sample
 (nM) * Proline: concentration of the amino acid proline in each water
 sample (nM) * Threonine: concentration of the amino acid threonine in each
 water sample (nM) * Glycine: concentration of the amino acid glycine in
 each water sample (nM) * Glutamine: concentration of the amino acid
 glutamine in each water sample (nM) * Glutamic.Acid: concentration of the
 amino acid glutamic acid in each water sample (nM) * Tyrosine:
 concentration of the amino acid tyrosine in each water sample (nM) *
 Asparagine: concentration of the amino acid asparagine in each water
 sample (nM) * Aspartic.Acid: concentration of the amino acid aspartic acid
 in each water sample (nM) * Arginine: concentration of the amino acid
 arginine in each water sample (nM) * Cysteine: concentration of the amino
 acid cysteine in each water sample (nM)