Mechanisms underlying natural variation in otolith elemental fingerprints of larval lake whitefish
Data files
Apr 28, 2026 version files 822.48 KB
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2014_Sampling_Lat_Long.csv
4.84 KB
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2014_Unassasigned_Clustering.R
8.80 KB
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2014_Unassigned_Clustering.csv
14.39 KB
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2014_with_clust_ID.csv
19.86 KB
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LWF_Combined_LDA.R
18.28 KB
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Otolith_Microchem_Outputs_Combined_Adjusted.csv
10.92 KB
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Otolith_Microchem_Outputs_Combined_Reclass.csv
10.64 KB
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Otolith_Microchem_Outputs_Combined.csv
10.79 KB
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README.md
7.43 KB
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water_temp_F.csv
360.17 KB
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water_temp_M.csv
356.36 KB
Abstract
Fish otolith elemental composition is used to infer natal origins and early life histories, but the relative roles of environmental exposure versus maternal influences remain uncertain for many species. We examined otolith elemental fingerprints of larval lake whitefish (Coregonus clupeaformis) in Green Bay, Lake Michigan, finding two distinct geochemical groupings among wild-caught larvae. To identify mechanisms generating this variation, we conducted a reciprocal transplant experiment testing whether incubation environment drives larval otolith signatures. Larval signatures differed primarily by maternal spawning origin, while incubation environment contributed minimally. Classification analyses showed high assignment success to maternal source, with most misclassification among groups sharing maternal origin. These results indicate that maternally associated chemical signatures dominate larval otolith fingerprints through early development, complicating interpretation of larval otolith chemistry as a "natal environment" signal. Our findings clarify when larval signatures likely reflect maternal provenance versus environmental exposure and highlight the need for additional reference collections and temporal validation to strengthen natal assignment frameworks in the Great Lakes.
Dataset DOI: 10.5061/dryad.r2280gbqx
Description of the data and file structure
The elemental composition of initial otolith layers often reflects foraging and environmental conditions experienced by the mother prior to spawning. Maternal geochemical signatures in otoliths have been used to reconstruct various aspects of maternal life histories. However, several assumptions regarding the formation of geochemical “tags” have not been thoroughly investigated. The goals of this study were to 1) develop a management tool for delineating natal origins of larval lake whitefish (Coregonus clupeaformis) in Green Bay, Lake Michigan, 2) evaluate the physiological aspects of element incorporation and geochemical implications to the otoliths of larval lake whitefish. We found that maternal influences drive larval otolith signatures of this species in the Green Bay system. This invalidates our assumption that incubation site was the predominant factor driving observed differences in larvae from different tributaries. Additionally, it seems likely that larvae with Green Bay origin are advected to the northern waters of Lake Michigan in considerable numbers and that river-run fish likely account for a measurable number of young-of-the-year whitefish in Green Bay.
Files and variables
File: Otolith_Microchem_Outputs_Combined.csv
Description: Elemental outputs of eight different trace element ratios to calcium from the otoliths of larval lake whitefish belonging to five different experimental treatment groups.
Variables
- Sample: signifier of treatment group
- Li7/Ca43: ratio of lithium to calcium43
- Na23/Ca43: ratio of sodium to calcium43
- Mg24/Ca43: ratio of magnesium to calcium43
- Ca44/Ca43: ratio of calcium44 to calcium43
- Mn55/Ca43: ratio of manganese to calcium43
- Zn66/Ca43: ratio of zinc to calcium43
- Sr88/Ca43: ratio of strontium to calcium43
- Ba137/Ca43: ratio of barium to calcium43
File: Otolith_Microchem_Outputs_Combined_Reclass.csv
Description: Elemental outputs of eight different trace element ratios to calcium from the otoliths of larval lake whitefish belonging to the same treatment groups as the previous dataset, however, Sample ID has been changed to reflect only the location of maternal spawning (Fox vs Menominee River).
Variables
- Sample: signifier of maternal spawning location
- Li7/Ca43: ratio of lithium to calcium43
- Na23/Ca43: ratio of sodium to calcium43
- Mg24/Ca43: ratio of magnesium to calcium43
- Ca44/Ca43: ratio of calcium44 to calcium43
- Mn55/Ca43: ratio of manganese to calcium43
- Zn66/Ca43: ratio of zinc to calcium43
- Sr88/Ca43: ratio of strontium to calcium43
- Ba137/Ca43: ratio of barium to calcium43
File: 2014_Unassigned_Clustering.csv
Description: Elemental outputs of six different trace element ratios to calcium from the otoliths of larval lake whitefish belonging to wild lake whitefish larvae collected at open water locations in 2014.
Variables
- Li7: ratio of lithium to calcium43
- Na23: ratio of sodium to calcium43
- Mg24: ratio of magnesium to calcium43
- Zn66: ratio of zinc to calcium43
- Sr88: ratio of strontium to calcium43
- Ba137: ratio of barium to calcium43
File: 2014_with_clust_ID.csv
Description
Elemental outputs of six different trace element ratios to calcium from the otoliths of larval lake whitefish belonging to wild lake whitefish larvae collected at open water locations in 2014, as well as assigned clustering identity from previous analysis.
Variables
- fit.cluster: assigned clustering ID
- Li7: ratio of lithium to calcium43
- Na23: ratio of sodium to calcium43
- Mg24: ratio of magnesium to calcium43
- Zn66: ratio of zinc to calcium43
- Sr88: ratio of strontium to calcium43
- Ba137: ratio of barium to calcium43
File: 2014_Sampling_Lat_Long.csv
Description
Sampling locations for larvae collected during 2014 open water surveys.
Variables
- Sample_ID: identifier of sample location
- region: region of the surrounding area closest to the sampling location
- section: section of Green Bay the sample site resided in
- site: specific site ID within sampling location
- year: year of sampling
- event: sampling event number
- lat: latitude of sampling location
- long: longitude of sampling location
File: Otolith_Microchem_Outputs_Combined_Adjusted.csv
Description
Elemental outputs of eight different trace element ratios to calcium from the otoliths of larval lake whitefish belonging to five different experimental treatment groups. Trace element ratios represent an alternative data reduction window from the primary data sets used in this manuscript.
Variables
- Sample: signifier of treatment group
- Li7/Ca43: ratio of lithium to calcium43
- Na23/Ca43: ratio of sodium to calcium43
- Mg24/Ca43: ratio of magnesium to calcium43
- Ca44/Ca43: ratio of calcium44 to calcium43
- Mn55/Ca43: ratio of manganese to calcium43
- Zn66/Ca43: ratio of zinc to calcium43
- Sr88/Ca43: ratio of strontium to calcium43
- Ba137/Ca43: ratio of barium to calcium43
File: water_temp_F.csv
Description
Water temps from a gauging station on the Fox River during the incubation period for experimental larvae.
Variables
- agency_cd: Agency maintaining monitoring station (USGS)
- site_no: site identifier
- datetime: numerical date and time in coordinated universal time (Excel Format)
- tz_cd: time zone
- X157329_00010: Temperature (degrees Celsius)
File: water_temp_M.csv
Description
Water temps from a gauging station on the Menominee River during the incubation period for experimental larvae.
Variables
- agency_cd: Agency maintaining monitoring station (USGS)
- site_no: site identifier
- datetime: numerical date and time in coordinated universal time (Excel Format)
- tz_cd: time zone
- X157123_00010: Temperature (degrees Celsius)
Code/software
R Version 4.2.2
packages used were:
MASS
ggplot2
scales
ggpubr
plottrix
mclust
fpc
cluster
factoextra
plotly
ggfortify
R Files
File: LWF_Combined_LDA.R
Description
R code utilizing data from "Otolith_Microchem_Outputs_Combined.csv" and "Otolith_Microchem_Outputs_Combined_Reclass.csv" for multivariate analyses and separation of treatment groups. Analyses were run in R studio version (4.2.2). The working directory was set to desktop, which is where files were saved at the time of analysis. Loaded packages include dplyr, MASS, ggplot2, scales, ggpubr, and plotrix.
File 2014_Unassasigned_Clustering.R
Description
R Code Utilizing data from "2014_Unassigned_Clustering.csv' for unassigned clustering analysis and subsequent multivariate analysis. Analyses were run in R studio version (4.2.2). The working directory was set to desktop, which is where files were saved at the time of analysis. Loaded packages include mclust, fpc, cluster, dplyr, MASS, ggplot2, factoextra, scales, ggpubr.
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
Experimental otolith chemistry outputs from larval lake whitefish reared in 2023 and wild lake whitefish larvae from 2014.
