DOI: 10.5281/zenodo.16173644
title: Data Frames for Spatial-Temporal Patterns of Perfluoroalkyl Substances in the Biota of the Laurentian Great Lakes: A Meta-Analysis

description: Directory

This site contains the two finalized, imputed data frames generated from the workflow of Martin et al. (2026): Spatial-Temporal Patterns of Perfluoroalkyl Substances in the Biota of the Laurentian Great Lakes: A Meta-Analysis. These two datasets were used to construct generalized additive models (GAMs) for the concentrations of six per- and polyfluoroalkyl substances (PFAS) commonly detected in tissue samples of biota from the watersheds of the Laurentian Great Lakes. The compiled dataset includes 76 species/genera from eight taxonomic groups and seven trophic levels. Fish (Pisces: 50 species and 1,681 samples) and birds (Aves: 8 species and 633 samples) were the most frequently surveyed taxonomic groups. The most prominent trophic levels in the data were Quaternary Consumers (i.e., large-bodied piscivorous fish like salmon and pike; 15 species and 1,163 samples) and Piscivorous/Insectivorous Birds (e.g., gulls and cormorants; 6 species and 444 samples). Descriptions of the two datasets included in the .zip file are as follows:





Finalized_Imputed_Data_Frame.csv: this file stores the finalized data frame used in modeling for six PFAS (PFOS, PFNA, PFDA, PFUnA, PFDoA, and PFTrDA). A total of 2,489 samples from 50 studies are included in the file (Table 1), with left-censored concentration values imputed using log-ratio Expectation-Maximization and Data Augmentation algorithms from the zCompositions package (Palarea-Albaladejo & Martín-Fernández, 2015). For a thorough description of the different variables included in the data frame, please see the accompanying table (Table 2).




Finalized_Supp_Validation_Data_Frame.csv: this file contains the set of 8 formatted data points that are used with the test set (Finalized_Imputed_Data_Frame.csv was split into 80% training and 20% test sets during modeling) to assess the predictive accuracy of the six GAMs. The set of included variables, as well as the general formatting, mirror the Finalized_Imputed_Data_Frame.csv file.





Citation Information


If you wish to use the finalized dataset for research purposes, please cite our publication (Martin et al., 2026), version v1.0.0 of the corresponding GitHub repository (Martin et al., 2026; https://doi.org/10.5281/zenodo.18683257), and this Zenodo data repository (Martin et al., 2025; https://doi.org/10.5281/zenodo.16173643).

**Disclaimer**

PLEASE NOTE: The release contains data that have been heavily formatted and processed for this meta-analysis. The data frame has not been reviewed or approved by agencies or entities that may have been involved in the individual studies included in the meta-analysis. In several cases, some of the meta-data associated with this data frame's samples were calculated as averages of ranges provided in the respective publications (e.g., an estimated average collection date of May 15th for samples that were collected from April-June). As a result, exact meta-data values may, in some cases, be inaccurate for specific samples, which is merely reflective of the information that was available in the publications for those samples. If copies of the original raw data files are desired, we recommend contacting the corresponding authors of the appropriate papers and/or accessing the data portals where those files are available. The data sources we used for this project are provided in Table 1.

To access the code used to generate these two data frames and model PFAS concentrations, please refer to the GitHub repository link at the bottom of the page.
description: Table 1 Summary table of the publications and surveys included in the present study, with the dataset code, full citation, and data source provided. “Missing datasets” from this table (e.g., #3, #4, #13, etc.) were eliminated from the data frame both during the screening phase of our systematic search of the literature and during the process of assigning watershed designations to samples, using our custom shapefile of the Laurentian Great Lakes watersheds.










Dataset Code



Full Citation



Data Source





#1 Su et al (2017)



Su, G., Letcher, R. J., Moore, J. N., Williams, L. L., & Grasman, K. A. (2017). Contaminants of emerging concern in Caspian tern compared to herring gull eggs from Michigan colonies in the Great Lakes of North America. Environmental Pollution, 222, 154-164. https://doi.org/10.1016/j.envpol.2016.12.061



Corresponding AuthorR. J. Letcher





#2 De Silva et al (2009)



De Silva, A. O., Muir, D. C., & Mabury, S. A. (2009). Distribution of perfluorocarboxylate isomers in select samples from the North American environment. Environmental Toxicology and Chemistry: An International Journal, 28(9), 1801-1814. https://doi.org/10.1897/08-500.1



Available from the Publication





#5 Furdui et al (2008)



Furdui, V. I., Helm, P. A., Crozier, P. W., Lucaciu, C., Reiner, E. J., Marvin, C. H., Whittle, D. M., Mabury, S. A., & Tomy, G. T. (2008). Temporal trends of perfluoroalkyl compounds with isomer analysis in lake trout from Lake Ontario (1979− 2004). Environmental science & technology, 42(13), 4739-4744. https://doi.org/10.1021/es7032372



Corresponding AuthorV. I. Furdui





#6 Custer et al (2009)



Custer, T. W., Kannan, K., Tao, L., Saxena, A. R., & Route, B. (2009). Perfluorinated compounds and polybrominated diphenyl ethers in great blue heron eggs from Indiana Dunes National Lakeshore, Indiana. Journal of Great Lakes Research, 35(3), 401-405. https://doi.org/10.1016/j.jglr.2009.02.003



Corresponding AuthorK. Kannan





#7 Point et al (2021)



Point, A. D., Holsen, T. M., Fernando, S., Hopke, P. K., & Crimmins, B. S. (2021). Trends (2005–2016) of perfluoroalkyl acids in top predator fish of the Laurentian Great Lakes. Science of the Total Environment, 778, 146151. https://doi.org/10.1016/j.scitotenv.2021.146151



Corresponding AuthorA. D. PointorGLENDA Query System (https://cdx.epa.gov/)Brian Lenell (lenell.brian@epa.gov)





#8 Munoz et al (2022)



Munoz, G., Mercier, L., Duy, S. V., Liu, J., Sauvé, S., & Houde, M. (2022). Bioaccumulation and trophic magnification of emerging and legacy per-and polyfluoroalkyl substances (PFAS) in a St. Lawrence River food web. Environmental Pollution, 309, 119739. https://doi.org/10.1016/j.envpol.2022.119739



Available from the Publication





#9 Gewurtz et al (2012)



Gewurtz, S. B., De Silva, A. O., Backus, S. M., McGoldrick, D. J., Keir, M. J., Small, J., Melymuk, L., & Muir, D. C. (2012). Perfluoroalkyl contaminants in Lake Ontario Lake Trout: detailed examination of current status and long-term trends. Environmental science & technology, 46(11), 5842-5850. https://doi.org/10.1021/es3006095



Corresponding AuthorA. O. De Silva, S. B. Gewurtz & T. McDaniel





#10 Chu et al (2016)



Chu, S., Letcher, R. J., McGoldrick, D. J., & Backus, S. M. (2016). A new fluorinated surfactant contaminant in biota: perfluorobutane sulfonamide in several fish species. Environmental Science & Technology, 50(2), 669-675. https://doi.org/10.1021/acs.est.5b05058



Available from the Publication





#11 Furdui et al (2007)



Furdui, V. I., Stock, N. L., Ellis, D. A., Butt, C. M., Whittle, D. M., Crozier, P. W., Reiner, E. J., Muir, D. C., & Mabury, S. A. (2007). Spatial distribution of perfluoroalkyl contaminants in lake trout from the Great Lakes. Environmental science & technology, 41(5), 1554-1559. https://doi.org/10.1021/es0620484



Corresponding AuthorV. I. Furdui





#12 Letcher et al (2015)



Letcher, R. J., Su, G., Moore, J. N., Williams, L. L., Martin, P. A., de Solla, S. R., & Bowerman, W. W. (2015). Perfluorinated sulfonate and carboxylate compounds and precursors in herring gull eggs from across the Laurentian Great Lakes of North America: Temporal and recent spatial comparisons and exposure implications. Science of the Total Environment, 538, 468-477. https://doi.org/10.1016/j.scitotenv.2015.08.083



Available from the Publication





#15 Kannan et al (2005)



Kannan, K., Tao, L., Sinclair, E., Pastva, S. D., Jude, D. J., & Giesy, J. P. (2005). Perfluorinated compounds in aquatic organisms at various trophic levels in a Great Lakes food chain. Archives of environmental contamination and toxicology, 48, 559-566. https://doi.org/10.1007/s00244-004-0133-x



Available from the Publication





#16 Gewurtz et al (2014)



Gewurtz, S. B., Bhavsar, S. P., Petro, S., Mahon, C. G., Zhao, X., Morse, D., Reiner, E. J., Tittlemier, S. A., Braekevelt, E., & Drouillard, K. (2014). High levels of perfluoroalkyl acids in sport fish species downstream of a firefighting training facility at Hamilton International Airport, Ontario, Canada. Environment International, 67, 1-11. https://doi.org/10.1016/j.envint.2014.02.005



Available from the Publication





#17 Houde et al (2008)



Houde, M., Czub, G., Small, J. M., Backus, S., Wang, X., Alaee, M., & Muir, D. C. (2008). Fractionation and bioaccumulation of perfluorooctane sulfonate (PFOS) isomers in a Lake Ontario food web. Environmental science & technology, 42(24), 9397-9403. https://doi.org/10.1021/es800906r



Corresponding AuthorD. C. Muir & M. Houde





#18 Gebbink et al (2009)



Gebbink, W. A., Hebert, C. E., & Letcher, R. J. (2009). Perfluorinated carboxylates and sulfonates and precursor compounds in herring gull eggs from colonies spanning the Laurentian Great Lakes of North America. Environmental science & technology, 43(19), 7443-7449. https://doi.org/10.1021/es901755q



Available from the Publication





#19 Ren et al (2022)



Ren, J., Point, A., Baygi, S. F., Fernando, S., Hopke, P. K., Holsen, T. M., ... & Crimmins, B. S. (2022). Bioaccumulation of perfluoroalkyl substances in a Lake Ontario food web. Journal of Great Lakes Research, 48(2), 315-325. https://doi.org/10.1016/j.jglr.2021.08.013

The Great Lakes Fish Monitoring and Surveillance Program; Clarkson University



GLENDA Query System (https://cdx.epa.gov/)Brian Lenell (lenell.brian@epa.gov)





#20 Gebbink and Letcher (2012)



Gebbink, W. A., & Letcher, R. J. (2012). Comparative tissue and body compartment accumulation and maternal transfer to eggs of perfluoroalkyl sulfonates and carboxylates in Great Lakes herring gulls. Environmental pollution, 162, 40-47. https://doi.org/10.1016/j.envpol.2011.10.011



Available from the Publication





#21 Sun et al (2020)



Sun, J., Letcher, R. J., Eens, M., Covaci, A., & Fernie, K. J. (2020). Perfluoroalkyl acids and sulfonamides and dietary, biological and ecological associations in peregrine falcons from the Laurentian Great Lakes Basin, Canada. Environmental Research, 191, 110151. https://doi.org/10.1016/j.envres.2020.110151



Available from the Publication





#22 Guo et al (2012)



Guo, R., Reiner, E. J., Bhavsar, S. P., Helm, P. A., Mabury, S. A., Braekevelt, E., & Tittlemier, S. A. (2012). Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region. Analytical and bioanalytical chemistry, 404, 2699-2709. https://doi.org/10.1007/s00216-012-6125-1



Available from the Publication





#25 Dykstra et al (2021)



Dykstra, C. R., Route, W. T., & Williams, K. A. (2021). Trends and patterns of perfluoroalkyl substances in blood plasma samples of bald eagle nestlings in Wisconsin and Minnesota, USA. Environmental Toxicology and Chemistry, 40(3), 754-766. https://doi.org/10.1002/etc.4864



Corresponding AuthorW. T. Route





#26 De Silva et al (2011)



De Silva, A. O., Spencer, C., Scott, B. F., Backus, S., & Muir, D. C. (2011). Detection of a cyclic perfluorinated acid, perfluoroethylcyclohexane sulfonate, in the Great Lakes of North America. Environmental Science & Technology, 45(19), 8060-8066. https://doi.org/10.1021/es200135c



Available from the Publication





#27 Gebbink and Letcher (2010)



Gebbink, W. A., & Letcher, R. J. (2010). Linear and branched perfluorooctane sulfonate isomer patterns in herring gull eggs from colonial sites across the Laurentian Great Lakes. Environmental science & technology, 44(10), 3739-3745. https://doi.org/10.1021/es100474r



Available from the Publication





#28 Asher et al (2012)



Asher, B. J., Wang, Y., De Silva, A. O., Backus, S., Muir, D. C., Wong, C. S., & Martin, J. W. (2012). Enantiospecific perfluorooctane sulfonate (PFOS) analysis reveals evidence for the source contribution of PFOS-precursors to the Lake Ontario foodweb. Environmental science & technology, 46(14), 7653-7660. https://doi.org/10.1021/es301160r



Available from the Publication





#29 Wu et al (2019)



Wu, Y., Simon, K. L., Best, D. A., Bowerman, W., & Venier, M. (2020). Novel and legacy per-and polyfluoroalkyl substances in bald eagle eggs from the Great Lakes region. Environmental Pollution, 260, 113811. https://doi.org/10.1016/j.envpol.2019.113811



Available from the Publication





#30 Martin et al (2004)



Martin, J. W., Whittle, D. M., Muir, D. C., & Mabury, S. A. (2004). Perfluoroalkyl contaminants in a food web from Lake Ontario. Environmental science & technology, 38(20), 5379-5385. https://doi.org/10.1021/es049331s



Corresponding AuthorJ. W. Martin





#33 Gewurtz et al (2016)



Gewurtz, S. B., Martin, P. A., Letcher, R. J., Burgess, N. M., Champoux, L., Elliott, J. E., & Weseloh, D. C. (2016). Spatio-temporal trends and monitoring design of perfluoroalkyl acids in the eggs of gull (Larid) species from across Canada and parts of the United States. Science of The Total Environment, 565, 440-450. https://doi.org/10.1016/j.scitotenv.2016.04.149



Available from the Publication





#34 GLHHFTS (2010)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Coastal Condition Assessment: Great Lakes Human Health Fish Tissue Studies 2010. https://www.epa.gov/fish-tech/national-coastal-condition-assessment-great-lakes-human-health-fish-tissue-studies



GLHH FTS Program Website





#34 GLHHFTS (2015)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Coastal Condition Assessment: Great Lakes Human Health Fish Tissue Studies 2015. https://www.epa.gov/fish-tech/national-coastal-condition-assessment-great-lakes-human-health-fish-tissue-studies



GLHH FTS Program Website





TEST GLHHFTS (2020)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Coastal Condition Assessment: Great Lakes Human Health Fish Tissue Studies 2020. https://www.epa.gov/fish-tech/national-coastal-condition-assessment-great-lakes-human-health-fish-tissue-studies



GLHH FTS Program Website





#34 NRSA FTS (2008-2009)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Rivers and Streams Assessment 2008-2009. https://www.epa.gov/national-aquatic-resource-surveys/nrsa



NRSA FTS Program Website





#34 NRSA FTS (2013-2014)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Rivers and Streams Assessment 2013-2014. https://www.epa.gov/national-aquatic-resource-surveys/nrsa



NRSA FTS Program Website





#34 NRSA FTS (2018-2019)



United States Environmental Protection Agency (2024). National Aquatic Resource Surveys. National Rivers and Streams Assessment 2018-2019. https://www.epa.gov/national-aquatic-resource-surveys/nrsa



NRSA FTS Program Website





#36 Custer et al (2016)



Custer, T. W., Custer, C. M., Dummer, P. M., Goldberg, D., Franson, J. C., & Erickson, R. A. (2017). Organic contamination in tree swallow (Tachycineta bicolor) nestlings at United States and binational Great Lakes Areas of Concern. Environmental toxicology and chemistry, 36(3), 735-748. https://doi.org/10.1002/etc.3598



Custer, T.W., 2016, Birds as indicators of contaminants in the Great Lakes: Nestling Bioindicators: U.S. Geological Survey data release, https://doi.org/10.5066/F7FF3QG7.





#37 De Silva et al (2016)



De Silva, A. O., Spencer, C., Ho, K. C. D., Al Tarhuni, M., Go, C., Houde, M., de Solla, S. R., Lavoie, R. A., King, L. E., Muir, D. C. G., Fair, P. A., Wells, R. S., & Bossart, G. D. (2016). Perfluoroalkylphosphinic acids in northern pike (Esox lucius), double-crested cormorants (Phalacrocorax auritus), and bottlenose dolphins (Tursiops truncatus) in relation to other perfluoroalkyl acids. Environmental Science & Technology, 50(20), 10903-10913. https://doi.org/10.1021/acs.est.6b03515



Available from the Publication





#38 Ren et al (2022)



Ren, J., Point, A. D., Baygi, S. F., Fernando, S., Hopke, P. K., Holsen, T. M., & Crimmins, B. S. (2022). Bioaccumulation of polyfluoroalkyl substances in the Lake Huron aquatic food web. Science of The Total Environment, 819, 152974. https://doi.org/10.1016/j.scitotenv.2022.152974

The Great Lakes Fish Monitoring and Surveillance Program; Clarkson University



GLENDA Query System (https://cdx.epa.gov/)Brian Lenell (lenell.brian@epa.gov)





#42 Moody et al (2002)



Moody, C. A., Martin, J. W., Kwan, W. C., Muir, D. C., & Mabury, S. A. (2002). Monitoring perfluorinated surfactants in biota and surface water samples following an accidental release of fire-fighting foam into Etobicoke Creek. Environmental science & technology, 36(4), 545-551. https://doi.org/10.1021/es011001+



Available from the Publication





#44 Custer et al (2019)



Custer, C. M., Custer, T. W., Delaney, R., Dummer, P. M., Schultz, S., & Karouna-Renier, N. (2019). Perfluoroalkyl contaminant exposure and effects in tree swallows nesting at Clarks Marsh, Oscoda, Michigan, USA. Archives of environmental contamination and toxicology, 77, 1-13. https://doi.org/10.1007/s00244-019-00620-1



Custer, C.M., Custer, T.W., Delaney, R., Dummer, P.M., Schultz, S., and Karouna-Renier, N., 2019, Perfluoroalkyl contaminant exposure in tree swallows nesting at Clarks Marsh, Oscoda, MI dataset: U.S. Geological Survey data release, https://doi.org/10.5066/P9KKECVJ.





#46 Oakes et al (2010)



Oakes, K. D., Benskin, J. P., Martin, J. W., Ings, J. S., Heinrichs, J. Y., Dixon, D. G., & Servos, M. R. (2010). Biomonitoring of perfluorochemicals and toxicity to the downstream fish community of Etobicoke Creek following deployment of aqueous film-forming foam. Aquatic Toxicology, 98(2), 120-129. https://doi.org/10.1016/j.aquatox.2010.02.005



Available from the Publication





#47 Miranda et al (2023)



Miranda, D. A., Zachritz, A. M., Whitehead, H. D., Cressman, S. R., Peaslee, G. F., & Lamberti, G. A. (2023). Occurrence and biomagnification of perfluoroalkyl substances (PFAS) in Lake Michigan fishes. Science of The Total Environment, 895, 164903. https://doi.org/10.1016/j.scitotenv.2023.164903



Corresponding AuthorD. A. Miranda





#48 George et al (2023)



George, S. E., Baker, T. R., & Baker, B. B. (2023). Nonlethal detection of PFAS bioaccumulation and biomagnification within fishes in an urban-and wastewater-dominant Great Lakes watershed. Environmental Pollution, 321, 121123. https://doi.org/10.1016/j.envpol.2023.121123



Available from the Publication





#49 Conard et al (2022)



Conard, W. M., Whitehead, H. D., Harris, K. J., Lamberti, G. A., Peaslee, G. F., & Rand, A. A. (2022). Maternal offloading of per-and polyfluoroalkyl substances to eggs by Lake Michigan salmonids. Environmental Science & Technology Letters, 9(11), 937-942. https://doi.org/10.1021/acs.estlett.2c00627



Corresponding AuthorW. M. Conard





#50 Ren et al (2023)



Ren, J., Point, A. D., Baygi, S. F., Fernando, S., Hopke, P. K., Holsen, T. M., & Crimmins, B. S. (2023). Bioaccumulation of perfluoroalkyl substances in the Lake Erie food web. Environmental Pollution, 317, 120677. https://doi.org/10.1016/j.envpol.2022.120677

The Great Lakes Fish Monitoring and Surveillance Program; Clarkson University



GLENDA Query System (https://cdx.epa.gov/)Brian Lenell (lenell.brian@epa.gov)





#53 Hebert et al (2022)



Hebert, C. E., Letcher, R. J., Cyr, F., & Drake, C. (2022). Fatty acid ecological tracers highlight the role of diet in perfluoroalkyl acid contaminant exposure in eggs of an omnivorous bird. Journal of Great Lakes Research, 48(5), 1270-1277. https://doi.org/10.1016/j.jglr.2022.08.010



Available from the Publication





#56 Hopkins et al (2023)



Hopkins, K. E., McKinney, M. A., Letcher, R. J., & Fernie, K. J. (2023). The influence of environmental and ecological factors on the accumulation and distribution of short-and long-chain perfluoroalkyl acids in a mid-trophic avian insectivore. Environmental Pollution, 321, 121133. https://doi.org/10.1016/j.envpol.2023.121133



Available from the Publication





#57 Coy et al (2022)



Coy, C. O., Steele, A. N., Abdulelah, S. A., Belanger, R. M., Crile, K. G., Stevenson, L. M., & Moore, P. A. (2022). Differing behavioral changes in crayfish and bluegill under short-and long-chain PFAS exposures: Field study in Northern Michigan, USA. Ecotoxicology and Environmental Safety, 247, 114212. https://doi.org/10.1016/j.ecoenv.2022.114212



Corresponding AuthorC. O. Coy





#58 De Solla et al (2012)



de Solla, S. R., De Silva, A. O., & Letcher, R. J. (2012). Highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, Hamilton, Ontario, Canada. Environment international, 39(1), 19-26. https://doi.org/10.1016/j.envint.2011.09.011



Available from the Publication





#63 Custer et al (2014)



Custer, C. M., Custer, T. W., Dummer, P. M., Etterson, M. A., Thogmartin, W. E., Wu, Q., Kannan, K., Trowbridge, A., & McKann, P. C. (2014). Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA. Archives of environmental contamination and toxicology, 66, 120-138. https://doi.org/10.1007/s00244-013-9934-0



Available from the Publication





#64 Route et al (Unpublished)



William Route (unpublished). United States National Park Service, Great Lakes Inventory and Monitoring Network, Ashland, WI 54891



Corresponding AuthorW. T. Route





#65 Kannan et al (2001)



Kannan, K., Franson, J. C., Bowerman, W. W., Hansen, K. J., Jones, P. D., & Giesy, J. P. (2001). Perfluorooctane sulfonate in fish-eating water birds including bald eagles and albatrosses. Environmental science & technology, 35(15), 3065-3070. https://doi.org/10.1021/es001935i



Available from the Publication





TEST Custer et al (2024)



Custer, C. M., Custer, T. W., Dummer, P. M., Schultz, S., Karouna‐Renier, N., Tseng, C. Y., & Matson, C. W. (2024). Exposure to and Biomarker Responses From Legacy and Emerging Contaminants Along Three Drainages in the Milwaukee Estuary, Wisconsin, USA. Environmental Toxicology and Chemistry, 43(4), 856-877. https://doi.org/10.1002/etc.5822



Custer, C.M., 2024, Pesticides in tree swallows from the Milwaukee Estuary, WI: U.S. Geological Survey data release, https://doi.org/10.5066/P9GJ25EC.





TEST Hopkins et al (2023)



Hopkins, K. E., McKinney, M. A., Saini, A., Letcher, R. J., Karouna-Renier, N. K., & Fernie, K. J. (2023). Characterizing the Movement of Per-and Polyfluoroalkyl Substances in an Avian Aquatic–Terrestrial Food Web. Environmental Science & Technology, 57(48), 20249-20260. https://doi.org/10.1021/acs.est.3c06944



Available from the PublicationandKarouna-Renier, N.K., Hopkins, K.E., and Fernie, K.J., 2024, Per- and Polyfluoroalkyl Substances in tree swallow gut contents: U.S. Geological Survey data release, https://doi.org/10.5066/P92J89EQ.









Table 2 Summary table of the predictor variables included in the initial stages of data collection for the meta-analysis.








Variable Name



Description



Type





Author..Citation.



The unique dataset code established for each study included in the meta-analysis(Table 1).



Categorical

Levels: 50 studies





Sample.ID



The unique value established for every sample included in the meta-analysis (usually values were already provided by each study).



Categorical

Levels: 2,489 samples





Latitude; Longitude



Geographical coordinates of the sample.



Continuous





Location



Description of the locality from which the sample was collected (provided by the publication/survey and not standardized across studies).



Categorical

Levels: 870 unique values





Waterbody



The watershed/lake basin within which the given sample was collected.



Categorical

Levels: Lake Superior; Lake Michigan; Lake Huron; Lake Erie; Lake Ontario





Waterbody_Type



The type of waterbody nearest to which the sample was collected.



Categorical

Levels: Inland waters; Connecting channels; Lake





Sampling.Year



The year during which the sample was collected.



Continuous





Collection.Date



The date on which the sample was collected (when raw data files were not available, the center point of the date range reported in the publication was entered).



Discrete





Season



The season during which the sample was collected. This value was only determined when collection date information was reported, and was one of two levels. The two levels represent the two dominant seasonal circulation patterns reported for the lake basins (Beletsky et al., 1999).



Categorical

Levels: Summer; Winter





Water_Level



The water level of the lake basin during the given sampling year, from data collected by the US Army Corps of Engineers, Great Lakes and Ohio River Division (available at https://www.lrd.usace.army.mil/Water-Information/Water-Management/Great-Lakes-and-Harbors/Water-Level-Data/). Data within each level of Waterbody was scaled to produce the Water_Level_sc variable.



Continuous





Species



The common name of the species sampled or, when species-level taxonomic resolution was not possible, the most refined designation (e.g., the name of the genus or family). Several labels were unified during data formatting to yield the Revised_Species variable.



Categorical

Levels: 76 unique values in the data frame





Class



The mono/paraphyletic group to which the sampled species/genus belongs.



Categorical

Levels: Algae; Plantae (Magnoliopsida); Shrimp, water fleas, and allies; Bivalvia; Zooplankton; Annelida; Insecta; Gastropoda; Astacoidea; Amphibia; Pisces; Mammalia; Aves; Reptilia





Trophic_Level



The common trophic position of the sampled species in a generalized Great Lakes food web. Labels were assigned based upon the reported feeding habits of each species included in the meta-analysis (Froese & Pauly, 2024).



Categorical

Levels: Primary Producer; Primary Consumer; Secondary Consumer; Tertiary Consumer; Quaternary Consumer; Piscivorous/Insectivorous Bird; Apex Predator





Tissue



The tissue type that was sampled from the organism. Labels were consolidated into six different levels (which are reported here) for the final Revised_Tissue variable. The “Misc. Tissue” level is used to designate all tissue types that did not fit into one of the other five categories, and was mostly dominated by carcass samples.



Categorical

Levels: Eggs, Blood, Liver, Muscle, Whole organism homogenate, Misc. Tissue





Composite



Whether the sample represents a single individual or a composite/a pooled sample.



Binary





Total.Length..cm.



The total length of the sampled organism, in units of centimeters (cm).



Continuous





Total.Weight..g.



The total weight of the sampled organism, in units of grams (g).



Continuous





Sex.Ratio



The ratio of females to males in the sample (a measure used to accommodate composite samples): a value of 0 represents all males and a value of 1 all females.



Continuous





Maturity



The sexual maturity of the organism: diverse Class-specific labels were consolidated in the Revised_Maturity variable to produce three different classifications.



Categorical

Levels: Juvenile/Immature; Adult (Non-reproductive); Adult (Reproductive)





Age..Years.



The age of the specimen when sampling was performed, in units of years.



Continuous





d13C; d15N



The isotopic signatures of carbon and nitrogen in the sample.



Continuous





n_samples; n_indiv



The number of experimental units and individual organisms, respectively, that are represented by each sample included in the meta-analysis. These values deviated from 1 when the publication only made summary tables, and not raw data files, available, or when the sampling design was such that only composite PFAS concentrations were estimated.



Discrete