Stable Isotopes

Linking Hydrogen (δ2H) Isotopes in Feathers and Precipitation: Sources of Variance and Consequences for Assignment to Isoscapes

by Keith Larson

Hobson, K. A., S. L. Van Wilgenburg, L. I. Wassenaar, and K. W. Larson. 2012. Linking Hydrogen (δ2H) Isotopes in Feathers and Precipitation: Sources of Variance and Consequences for Assignment to Isoscapes. PLoS ONE 7:e35137. doi: 10.1371/journal.pone.0035137.

BACKGROUND:

Tracking small migrant organisms worldwide has been hampered by technological and recovery... more BACKGROUND:

Tracking small migrant organisms worldwide has been hampered by technological and recovery limitations and sampling bias inherent in exogenous markers. Naturally occurring stable isotopes of H (δ(2)H) in feathers provide an alternative intrinsic marker of animal origin due to the predictable spatial linkage to underlying hydrologically driven flow of H isotopes into foodwebs. This approach can assess the likelihood that a migrant animal originated from a given location(s) within a continent but requires a robust algorithm linking H isotopes in tissues of interest to an appropriate hydrological isotopic spatio-temporal pattern, such as weighted-annual rainfall. However, a number of factors contribute to or alter expected isotopic patterns in animals. We present results of an extensive investigation into taxonomic and environmental factors influencing feather δ(2)H patterns across North America.

PRINCIPAL FINDINGS:

Stable isotope data were measured from 544 feathers from 40 species and 140 known locations. For δ(2)H, the most parsimonious model explaining 83% of the isotopic variance was found with amount-weighted growing-season precipitation δ(2)H, foraging substrate and migratory strategy.

CONCLUSIONS/SIGNIFICANCE:

This extensive H isotopic analysis of known-origin feathers of songbirds in North America and elsewhere reconfirmed the strong coupling between tissue δ(2)H and global hydrologic δ(2)H patterns, and accounting for variance associated with foraging substrate and migratory strategy, can be used in conservation and research for the purpose of assigning birds and other species to their approximate origin.

A groundwater isoscape (δD, δ 18O) for Mexico

by Keith Larson

Wassenaar, L. I., S. L. Van Wilgenburg, K. W. Larson, and K. A. Hobson. 2009. A groundwater isoscape (δD, δ18O) for Mexico. Journal of Geochemical Exploration 102:123–136. doi: 10.1016/j.gexplo.2009.01.001.

Numerous studies have shown that precipitation isocapes drive δD and δ18O patterns in surficial waters and in... more Numerous studies have shown that precipitation isocapes drive δD and δ18O patterns in surficial waters and in terrestrial food webs. While the GNIP (Global Network for Isotopes in Precipitation) dataset provided a key foundation for linking precipitation-terrestrial isoscapes globally, it has insufficient spatial coverage in many countries like Mexico. To overcome this limitation, we hypothesized that shallow phreatic groundwaters in Mexico could be used as an isotopic integrator of long-term seasonally weighted precipitation inputs to the landscape to aid in calibrating spatial H and O isotope datasets for terrestrial, biological and hydrological research. Groundwater was sampled from 234 sites in Mexico at ~50 km latitudinal spacing to obtain high spatial resolution and country-wide coverage for the construction of a groundwater isoscape. Our data revealed that shallow groundwater infiltration in Mexico appears largely unaffected by evaporation and reflects seasonally weighted precipitation inputs. These precipitation inputs are primarily biased to summertime when highest rainfall occurs, but a small degree of post-precipitation evaporation revealed a lower d-excess zone that corresponded to the interior semi-arid ecozone. We developed a predictive general linear model (GLM) for hydrogen and oxygen isotopic spatial patterns in Mexican groundwater and then compared the results to a validation subset of our field data, as well external data reported in the literature. The GLM used elevation, latitude, drainage basin (Atlantic vs. Pacific), and rainfall as the most relevant predictive variables. The GLM explained 81% of the overall isotopic variance observed in groundwater, 68% of the variance within our validation subset, and 77% of the variance in the external data set. Our predictive GLM is sufficiently accurate to allow for future ecological, hydrological and forensic isoscape applications in Mexico, and may be an approach that is applicable to other countries and regions where GNIP stations are lacking.

Assignment to breeding and wintering grounds using stable isotopes: a comment on lessons learned by Rocque et al.

by Keith Larson

Larson, K. W., and K. A. Hobson. 2009. Assignment to breeding and wintering grounds using stable isotopes: a comment on lessons learned by Rocque et al. Journal of Ornithology 150:709–712. doi: 10.1007/s10336-009-0408-0.

Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea mays)

by Paul Szpak

Szpak P., F. J. Longstaffe, J.-F. Millaire, C. D. White. 2012. Stable Isotope Biogeochemistry of Seabird Guano Fertilization: Results from Growth Chamber Studies with Maize (Zea mays). PLoS One 7: e33741.

Background
Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues... more Background
Stable isotope analysis is being utilized with increasing regularity to examine a wide range of issues (diet, habitat use, migration) in ecology, geology, archaeology, and related disciplines. A crucial component to these studies is a thorough understanding of the range and causes of baseline isotopic variation, which is relatively poorly understood for nitrogen (δ15N). Animal excrement is known to impact plant δ15N values, but the effects of seabird guano have not been systematically studied from an agricultural or horticultural standpoint.


Methodology/Principal Findings
This paper presents isotopic (δ13C and δ15N) and vital data for maize (Zea mays) fertilized with Peruvian seabird guano under controlled conditions. The level of 15N enrichment in fertilized plants is very large, with δ15N values ranging between 25.5 and 44.7‰ depending on the tissue and amount of fertilizer applied; comparatively, control plant δ15N values ranged between −0.3 and 5.7‰. Intraplant and temporal variability in δ15N values were large, particularly for the guano-fertilized plants, which can be attributed to changes in the availability of guano-derived N over time, and the reliance of stored vs. absorbed N. Plant δ13C values were not significantly impacted by guano fertilization. High concentrations of seabird guano inhibited maize germination and maize growth. Moreover, high levels of seabird guano greatly impacted the N metabolism of the plants, resulting in significantly higher tissue N content, particularly in the stalk.

Conclusions/Significance
The results presented in this study demonstrate the very large impact of seabird guano on maize δ15N values. The use of seabird guano as a fertilizer can thus be traced using stable isotope analysis in food chemistry applications (certification of organic inputs). Furthermore, the fertilization of maize with seabird guano creates an isotopic signature very similar to a high-trophic level marine resource, which must be considered when interpreting isotopic data from archaeological material.

Hydrogen and Oxygen Isotope Ratios in Body Water and Hair: Modeling Isotope Dynamics in Nonhuman Primates

by Luciano Valenzuela

The stable isotopic composition of drinking water, diet, and atmospheric oxygen influence the isotopic composition of... more The stable isotopic composition of drinking water, diet, and atmospheric oxygen influence the isotopic composition of body water (2H/1H, 18O/16O expressed as δ2H and δ18O). In turn, body water influences the isotopic composition of organic matter in tissues, such as hair and teeth, which are often used to reconstruct historical dietary and movement patterns of animals and humans. Here, we used a nonhuman primate system (Macaca fascicularis) to test the robustness of two different mechanistic stable isotope models: a model to predict the δ2H and δ18O values of body water and a second model to predict the δ2H and δ18O values of hair. In contrast to previous human-based studies, use of nonhuman primates fed controlled diets allowed us to further constrain model parameter values and evaluate model predictions. Both models reliably predicted the δ2H and δ18O values of body water and of hair. Moreover, the isotope data allowed us to better quantify values for two critical variables in the models: the δ2H and δ18O values of gut water and the 18O isotope fractionation associated with a carbonyl oxygen–water interaction in the gut (αow). Our modeling efforts indicated that better predictions for body water and hair isotope values were achieved by making the isotopic composition of gut water approached that of body water. Additionally, the value of αow was 1.0164, in close agreement with the only other previously measured observation (microbial spore cell walls), suggesting robustness of this fractionation factor across different biological systems.

Ambiente naturale e strategie agroalimentari in Puglia settentrionale tra tardo antico e alto medioevo: l’esempio di Faragola (FG)

by Valentina Caracuta

Caracuta V. 2011. Journal of Post-Classical  Archaeology 1, 275-295.

Britton, K., Gaudzinski-Windheuser, S., Roebroeks, W., Kindler, L., Richards, M.P., in press. Stable isotope analysis of well-preserved 120,000-year-old herbivore bone collagen from the Middle Palaeolithic site of Neumark-Nord 2, Germany reveals niche separation between bovids and equids. Palaeogeography, Palaeoclimatology, Palaeoecology (2012), doi:10.1016/j.palaeo.2012.03.028

by Sabine Gaudzinski-Windheuser

Herbivores from the Neumark-Nord 2 archaeological site, Germany, were analysed for bone collagen stable carbon (δ13C)... more Herbivores from the Neumark-Nord 2 archaeological site, Germany, were analysed for bone collagen stable carbon (δ13C) and nitrogen (δ15N) isotope ratios in order to investigate feeding ecology at this early Last Interglacial (Eemian) shallow-lake site. Of 42 faunal samples selected, 23 yielded collagen, demonstrating remarkable preservation for material of this age. The results indicate clear inter-specific differences in δ15N and
δ13C values, notably between equids (Equus) and bovids (Bos/Bison), with mean difference Δ15N of +2‰ measured in the bovids compared to the equids. The potential reasons for these differences are explored, including physiology, herbivore feeding ecology, biogeography and resource partitioning within the local environment. The data are compared to previously published archaeological data, and modern experimental and
ecological data, suggesting that these inter-specific differences are not consistent and therefore unlikely to be solely the product of physiology or habitual forage preference. Data from this study are compared to the local vegetation (as reconstructed from pollen profiles), and it is suggested that these trends are likely the result of niche partitioning at the shallow lake site, reflecting the local diversity in vegetational zones. The evidence for
resource partitioning amongst Pleistocene herbivore communities at Neumark-Nord 2 and elsewhere is discussed.
This study represents one of the largest data sets for collagen of this age, and the implications for our understanding of Late Pleistocene herbivore ecology, local herbivore community behaviour and hominin
palaeodietary studies are explored.

Marine Feeding Patterns of Anadromous Brook Trout (Salvelinus Fontinalis) Inhabiting An Estuarine River Fjord

by Genevieve Morinville

Dietary Heterogeneity among Western Industrialized Countries Reflected in the Stable Isotope Ratios of Human Hair

by Luciano Valenzuela

PLoS ONE

Although the globalization of food production is often assumed to result in a homogenization of consumption patterns... more Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization). Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardized diet or whether there is persistent heterogeneity and glocalization among countries as a result of different dietary patterns and the use of local food products. Here we report isotopic differences among carbon, nitrogen and sulfur isotope ratios of human hair collected in thirteen Western European countries and in the USA. European hair samples had significantly lower δ13C values (-22.7 to -18.3 ‰), and significantly higher δ15N (7.8 to 10.3 ‰) and δ34S (4.8 to 8.3 ‰) values than samples from the USA (δ13C: -21.9 to -15.0 ‰, δ15N: 6.7 to 9.9 ‰, δ34S: -1.2 to 9.9 ‰). Within Europe, we detected differences in hair δ13C and δ34S values among countries and covariation of isotope ratios with latitude and longitude. This geographic structuring of isotopic data suggests heterogeneity in the food resources used by citizens of industrialized nations and supports the presence of different dietary patterns within Western Europe despite globalization trends. Here we showed the potential of stable isotope analysis as a population-wide tool for dietary screening, particularly as a complement of dietary surveys, that can provide additional information on assimilated macronutrients and independent verification of data obtained by those self-reporting instruments.

Key words: Hair protein, stable isotopes, Western Europe, dietary heterogeneity, glocalization, globalization.

A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain

by Jane Evans

J. A. Evans, C. A. Chenery and J. Montgomery

This paper presents a compilation of strontium and oxygen isotope data from human tooth enamel that has been produced... more This paper presents a compilation of strontium and oxygen isotope data from human tooth enamel that has been produced at NERC Isotope Geosciences Laboratory over the last c.15 years. These many and often small studies are here combined to provide an overview of data from Britain. The strontium isotope composition ranges between 0.7078 and 0.7165 (excluding individuals deemed to be of non-British origin). The median Sr concentration is 84 ppm but there is a vector of increasing Sr concentrations related to seawater strontium isotope composition that is seen in individuals predominantly from the west coast of Scotland attributed to the used of kelp as a fertilizer. The oxygen isotope data is normally distributed with a mean value of 17.7‰ ± 1.4‰ (2SD n = 615). Two sub-populations of local individuals have been identified that provide control groups for human enamel values from the eastern side of Britain where there are lower rainfall levels: 17.2‰ ± 1.3‰, (2SD, n = 83) and western area of Britain where rainfall levels are higher = 18.2‰ ± 1‰, (2SD, n = 40). These data make it possible to make direct comparisons of population means between burial populations and the control dataset to assess commonality of origin.

Discrimination between farmed and free-living invasive salmonids in Chilean Patagonia using stable isotope analysis

by Carlos Garcia de Leaniz

Schröder,V.; Garcia de Leaniz,C.(2011). Biological Invasions 13: 203-213
DOI 10.1007/s10530-010-9802-z

In Chilean Patagonia relatively pristine aquatic environments are being modified by the introduction of exotic... more In Chilean Patagonia relatively pristine aquatic environments are being modified by the introduction of exotic salmonids, initially through their deliberate release for sport fishing since the early 20th century, and more recently via the accidental escape from fish farms. There is therefore a need to reliably distinguish between naturally reproducing and fugitive salmonids associated with the Chilean salmonid farming industry, the second largest in the world. We tested the ability of stable isotope analysis (SIA) and analysis of scale growth profiles to discriminate between farmed and free-living salmonids sampled around the Island of Chiloé. Juvenile Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) from aquaculture facilities were significantly more enriched in ä15N and lipid-corrected ä13C than river-caught individuals. Scale growth slopes during the first year in freshwater were significantly higher in farmed than in wild-caught rainbow trout, indicating faster somatic growth under hatchery conditions. Stable isotopes analysis classified 94% of juvenile Atlantic salmon and rainbow trout to their correct farm or free-living groups. Our results, therefore, can help to elucidate the origin and spread of exotic invasive salmonids in Chile, and address one of the biggest threats to native freshwater fishes in Patagonia and other temperate zones of the Southern Hemisphere. Keywords: stable isotope analysis, invasive species, salmonids, aquaculture

Empirical determination of oxygen isotope fractionation factors for titanite with respect to zircon and quartz

by Bart Kowallis

King, E.M., Valley, J.W., Davis, D.W., and Kowallis, B.J., 2001, Empirical determination of oxygen isotope fractionation factors for titanite with respect to zircon and quartz: Geochimica et Cosmochimica Acta, v. 65, p. 3165-3175.

Brewing and stewing: the effect of culturally mediated behaviour on the oxygen isotope composition of ingested fluids and the implications for human provenance studies

by Jane Evans

Brettell, Montgomery and Evans J. Anal. At. Spectrom., 2012, Advance Article
DOI: 10.1039/C2JA10335D

‘Small beer’, ‘wort drinks’ and ‘pottage’ may have been regularly consumed by children during the Medieval Period.... more ‘Small beer’, ‘wort drinks’ and ‘pottage’ may have been regularly consumed by children during the Medieval Period. This culturally mediated behaviour could have affected the oxygen isotope composition of their water intake beyond that which is accommodated in the current conversion equations used in archaeological studies to assess environmental origins. Experimental data shows that brewing may increase the δ18O value of ale by 1.3‰ over that of the initial water (‘liquor’) used, boiling water to make hot drinks raises the δ18O value of the fluid consumed by 0.4‰ and slow-cooking using a large stew pot results in an increase in the oxygen isotope composition of the ‘pottage’ by an average of 10.2‰ after 3 hours of cooking. Thus, if ingested fluids included 20% from ale, 10% from ‘teas’ and 20% from stews (the latter increased from −7.0‰ to +3.2‰ by three hours of cooking) then the overall effect on the calculated drinking water value from the tooth enamel will be +2.3‰.

Endangered species, archaeology, and stable isotopes: huemul (Hippocamelus bisulcus) isotopic ecology in central-western Patagonia (South America)

by Ramiro Barberena

R. BARBERENA, C. MÉNDEZ, F. MENA, O. REYES
(J. Arc. Sc. 2011)

The management and conservation of animal species should be based upon a long-term analysis that considers its... more The management and conservation of animal species should be based upon a long-term analysis that considers its geographical distribution and feeding patterns. The study of carbon and nitrogen stable isotopes on skeletal remains provides a quantitative approach to the paleodietary reconstructions and constitutes a potent tool for comparing behavioral aspects of the fauna. In this paper we present the first set of isotopic values for modern and archaeological samples of Huemul (Hippocamelus bisulcus) from the forests of Central-western Patagonia, Chile. Contrary to initial expectations, our analysis indicates that there is no evidence of an important incidence of the canopy effect on the δ13Ccollagen values, which we suggest is due to an ecological selection that drives the huemul to focus its predation on open sectors within the forest. On the other hand, a wide range of δ15Ncollagen values for huemul was verified. This could reflect the N impoverishment of the forest soils and provide an interesting ecological indicator. The long-term information offered by the archaeological record provides the necessary context for decision-making conducive towards the preservation of Hippocamelus bisulcus in Patagonia.

On the trophic ecology of Gammaridea (Crustacea: Amphipoda) in coastal waters: A European-scale analysis of stable isotopes data

by giorgio mancinelli

Detection of Counterfeit Scotch Whisky by 2H and 18O Stable Isotope Analysis

by Wolfram Meier-Augenstein

This article has been pre-published on-line but is not available in print yet.

Neat Scottish whiskies and the local source water used for and during whisky production have been analyzed for their... more Neat Scottish whiskies and the local source water used for and during whisky production have been analyzed for their 2H and 18O isotopic composition by High Temperature Conversion – Isotope Ratio Mass Spectrometry (TC/EA-IRMS).  With coefficients of determination R2 for d2H and d18O of 0.71 and 0.88, respectively, measured d2H and d18O values for water used in the production of Scottish Whisky were found to be well correlated with the d2H and d18O values observed for the corresponding whiskies.  By plotting bulk 2H against bulk 18O isotope abundance data of authentic whisky and counterfeit whisky samples it was possible to discriminate between samples of authentic whisky and samples of counterfeit whisky.

Reconstruction of late Pleistocene climate in the Valsequillo Basin (Central Mexico) through isotopic analysis of terrestrial and freshwater snails

by Rhiannon Stevens

Dynamics of Polynesian Subsistence: Insights from Archaeofauna and

by Melinda Allen

Published in Pacific Science 63:477-506, 2009.

Climatic, vegetation and cultural change in the eastern Mediterranean during the mid-Holocene environmental transition

by Valentina Caracuta

Neil Roberts,Warren J. Eastwood,Catherine Kuzucuogˇ lu, Girolamo Fiorentino, Valentina Caracuta
published in The Holocene 21(1) 147-162

Determining trophic niche width: An experimental test of the stable isotope approach

by Elke Reichwaldt

Fink, P., Reichwaldt, E.S., Harrod, C. & Rossberg, A.G. (2012) Determining trophic niche width: An experimental test of the stable isotope approach. Oikos (accepted, February 3, 2012)