Nitrogen isotopes in tooth enamel record diet and trophic level enrichment: Results from a controlled feeding experiment

2020 ◽  
pp. 120047
Author(s):  
Jennifer N. Leichliter ◽  
Tina Lüdecke ◽  
Alan D. Foreman ◽  
Nicolas N. Duprey ◽  
Daniela E. Winkler ◽  
...  
Keyword(s):  
Trophic Level ◽  
Nitrogen Isotopes ◽  
Tooth Enamel ◽  
Feeding Experiment

Use of stable-carbon and -nitrogen isotopes to assess weaning and fasting in female polar bears and their cubs

2001 ◽  
Vol 79 (3) ◽  
pp. 499-511 ◽  
Author(s):  
S C Polischuk ◽  
K A Hobson ◽  
M A Ramsay
Keyword(s):  
Stable Isotope ◽  
Trophic Level ◽  
Nitrogen Isotopes ◽  
Milk Proteins ◽  
Milk Lipid ◽  
Polar Bears ◽  
Stable Carbon ◽  
Stable Isotope Analyses ◽  
The Impact ◽  
Isotope Analyses

In some species, stable-isotope techniques can provide insights into dietary regimens where there are temporal shifts in trophic level or feeding frequency. We determined stable carbon (δ13C) and nitrogen (δ15N) isotope values for plasma and milk proteins and δ13C values for milk lipids from female polar bears (Ursus maritimus) and cubs to (i) ascertain whether cubs are at a higher trophic level than their mothers as a result of nursing and whether we can determine when weaning occurs, and (ii) determine the impact of seasonal fasting on δ13C and δ15N values. The plasma δ13C values for mothers and cubs were similar to milk-protein δ13C values and were significantly enriched in 13C compared with those for milk lipid. Plasma from cubs of the year (COYs) in spring, when milk was their only diet, was isotopically enriched in 15N by 1.0‰ over that of their mothers (δ15N = 21.5 ± 0.8‰ (mean ± SD) for cubs and 20.5 ± 0.5‰ for mothers) and depleted in 13C by 0.8 ‰ (δ13C = –19.6 ± 0.5‰ for cubs and –18.8 ± 0.8‰ for mothers). For bears who fasted between summer and fall (3–4 months), plasma became depleted in 13C by 0.5‰ and in 15N by 1‰. Plasma from females, who had fasted from summer to spring (7–8 months) and given birth to cubs, became enriched in 13C by 0.7‰ and in 15N by 2‰. By using stable-isotope analyses we were able to show that (i) young cubs were at a higher trophic level than their mother when milk was their only food source, and (ii) seasonal fasting influenced δ13C and δ15N values. However, we were not able to use stable-isotope analyses to determine the exact time of weaning.

scholarly journals Zinc isotopes from archaeological bones provide reliable tropic level information for marine mammals

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jeremy McCormack ◽  
Paul Szpak ◽  
Nicolas Bourgon ◽  
Michael Richards ◽  
Corrie Hyland ◽  
...  
Keyword(s):  
Trophic Level ◽  
Marine Mammals ◽  
Nitrogen Isotopes ◽  
Geographic Area ◽  
Marine Ecology ◽  
Dietary Analysis ◽  
Regional Food ◽  
Zinc Isotopes ◽  
Level Information ◽  
Discrimination Factors

AbstractIn marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate the geographic variability and trophic level isotopic discrimination factors of bone zinc 66Zn/64Zn ratios (δ66Zn value) and compared it to collagen nitrogen and carbon stable isotope (δ15N and δ13C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ66Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ15N and δ66Zn values in all locations, yet δ66Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ15N and δ13C analysis alone. When combining all three proxies, a more detailed and refined dietary analysis is possible.

Nitrogen isotopes and the trophic level of humans in archaeology

2007 ◽  
Vol 34 (8) ◽  
pp. 1240-1251 ◽  
Author(s):  
Robert E.M. Hedges ◽  
Linda M. Reynard
Keyword(s):  
Trophic Level ◽  
Nitrogen Isotopes

Advantages of zinc isotopes as a new dietary proxy in marine ecology

2020 ◽  
Author(s):  
Jeremy McCormack ◽  
Paul Szpak ◽  
Nicolas Bourgon ◽  
Michael P. Richards ◽  
Corrie Hyland ◽  
...  
Keyword(s):  
Trophic Level ◽  
Nitrogen Isotopes ◽  
Geographic Area ◽  
Marine Ecology ◽  
Trophic Levels ◽  
Dietary Analysis ◽  
Regional Food ◽  
Zinc Isotopes ◽  
Faunal Assemblages ◽  
Discrimination Factors

Abstract In marine ecology, dietary interpretations of faunal assemblages often rely on nitrogen isotopes as the main or only applicable trophic level tracer. We investigate geographic variability and trophic level isotopic discrimination factors of a new tracer, bone 66Zn/64Zn ratios (δ66Zn value), and compared it to collagen nitrogen and carbon stable isotope (δ15N and δ13C) values. Focusing on ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from multiple Arctic archaeological sites, we investigate trophic interactions between predator and prey over a broad geographic area. All proxies show variability among sites, influenced by the regional food web baselines. However, δ66Zn shows a significantly higher homogeneity among different sites. We observe a clear trophic spacing for δ15N and δ66Zn values in all locations, yet δ66Zn may more reliably record trophic levels between U. maritimus and prey species than δ15N. δ66Zn analysis allows a more direct dietary comparability between spatially and temporally distinct locations than what is possible by δ15N and δ13C analysis alone. When combining all three proxies a more detailed and refined dietary analysis is possible.

scholarly journals Stable isotopes, niche partitioning and the paucity of elasmosaur remains in the Maastrichtian type area

2016 ◽  
Vol 96 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Anne S. Schulp ◽  
Renée Janssen ◽  
Remy R. van Baal ◽  
John W.M. Jagt ◽  
Eric W.A. Mulder ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Late Cretaceous ◽  
Trophic Level ◽  
Tooth Enamel ◽  
Niche Partitioning ◽  
Skeletal Remains ◽  
Diving Behaviour ◽  
Foraging Area ◽  
Type Area

AbstractRemains of elasmosaurid plesiosaurs are exceedingly rare in the type-Maastrichtian strata (Late Cretaceous, southeast Netherlands and northeast Belgium), in stark contrast to relatively common skeletal remains of mosasaurs. Here, we present an analysis of δ13C stable isotope values for tooth enamel of two elasmosaur teeth from the type Maastrichtian. The δ13C signal is a proxy for foraging area, trophic level and diving behaviour, the net value of which in these rare elasmosaurs turns out to be not noticeably different from that for the much commoner mosasaurs in the type Maastrichtian. Therefore, the rarity of elasmosaurs in the area probably reflects a primary near-absence of such reptiles during the latest Cretaceous, rather than a taphonomic artefact.

Tooth Enamel Biogeochemistry and Early Hominin Diets

2017 ◽  
Author(s):  
Matt Sponheimer ◽  
Julia Lee-Thorp
Keyword(s):  
Trace Elements ◽  
Oxygen Isotope ◽  
Carbon Isotope ◽  
Trophic Level ◽  
Tooth Enamel ◽  
Isotope Composition ◽  
Oxygen Isotope Composition ◽  
Dietary Ecology ◽  
Isotope Analyses ◽  
Unambiguous Interpretation

Biogeochemical studies of hominin dietary ecology began decades ago, and, despite refinements, the basic tools being used and questions being asked have changed little since then. Carbon isotope analyses have had the most impact, with numerous studies showing that up to c.4 Ma, early hominins consumed primarily C3 vegetation, as do extant apes, but thereafter consumption of C4 foods became conspicuous if variable. Paranthropus boisei completely abandoned the ancestral C3 diet by at least 2 Ma to become a C4 consumer, a rarity among primates. These shifts were accompanied by changes in the australopith masticatory package. Applications using trace elements, particularly strontium and barium, as trophic level indicators have been less successful, partly because the distributions of trace elements in foodwebs are poorly understood. Similarly, while the oxygen isotope composition of tooth enamel unquestionably reflects ecology, the influences are complex and too poorly understood to allow unambiguous interpretation.

Reconstruction of the trophic levels of a fossil fish community from the Late Jurassic Solnhofen Archipelago

2020 ◽  
Author(s):  
Danijela Dimitrijevic ◽  
Martin Ebert ◽  
Martina Kölbl-Ebert ◽  
Axel Munnecke
Keyword(s):  
Trophic Level ◽  
Fossil Record ◽  
Late Jurassic ◽  
Fish Assemblages ◽  
Tooth Enamel ◽  
Trophic Levels ◽  
Mean Values ◽  
Functional Perspective ◽  
Diagenetic Alteration

<p>Trophic interactions of extinct fishes are central to our understanding of evolution, paleoecology and their role in the paleo-communities, but can be challenging, as these are limited by the incompleteness of the fossil record and by a lack of behavioural data. The extensive fossil record of Actinopterygii comes mostly from Conservation-Lagerstätten. They provide exceptionally rich information on fossil ecosystems and open outstanding windows into the evolution of life. The best-preserved Late Jurassic actinopterygians are known from the Solnhofen Archipelago, Germany. Despite that the diversity ichthyofauna of the Solnhofen Archipelago has been extensively explored in the last several decades, the dietary preferences of most fish remain unknown or have to be deduced by analogy from dentition and jaw morphology.</p><p>The aim of this study was to reconstruct the trophic levels of Late Jurassic fish assemblages using Sr/Ca and Ba/Ca measured from phosphatic fish remains, mostly ganoin and cycloid scales recovered from the Ettling locality, which is characterized by exceptionally well-preserved fossil fishes and moderate diagenetic alteration. We classified fish species into four trophic levels (durophagous, lower, middle, and higher trophic level) based on morphology available from the literature. Mean values of Sr, Ca, Ba and their ratios measured by Thermo Scientific iCAP Q inductively coupled plasma mass spectrometer in this study are in accordance with the mean values of previous studies. Differences in values between cleaned and uncleaned samples showed that the cleaning process successfully isolated primary dietary Sr content while dissolving away the diagenetic strontium present in carbonate in the pore spaces. All trophic levels showed low variation of Sr/Ca (0.003 - 0.008 μg/g) and high variation of Ba/Ca values (0.0003 - 0.0014 μg/g). The results showed significant differences between the middle and higher trophic levels (p = 0.03), while durophagous and lower trophic levels fell into the same range of values as the higher trophic level. </p><p>We demonstrate that enamel of fossil vertebrates from the Solnhofen Archipelago still contains near-in vivo Sr, Ba, and Ca. The clear distinction between middle and higher trophic levels offers a new functional perspective on the ecological and evolutionary relationships among fishes. However, future studies should not neglect the importance of diagenetic alteration of the samples; proper sample cleaning before measuring isotopic signatures, and careful selection of the analyzed tissue (i.e. tooth enamel instead of scales or bones due to its resistance to diagenesis).</p>

Relationship between morphometrics and trophic levels in deep-sea fishes

2020 ◽  
Vol 637 ◽  
pp. 225-235 ◽  
Author(s):  
MA Ladds ◽  
MH Pinkerton ◽  
E Jones ◽  
LM Durante ◽  
MR Dunn
Keyword(s):  
Stable Isotopes ◽  
Trophic Level ◽  
Deep Sea ◽  
Strong Relationship ◽  
Ecosystem Model ◽  
Trophic Levels ◽  
Fish Size ◽  
Wide Range ◽  
Gape Size ◽  
Morphological Variables

Marine food webs are structured, in part, by predator gape size. Species found in deep-sea environments may have evolved such that they can consume prey of a wide range of sizes, to maximise resource intake in a low-productivity ecosystem. Estimates of gape size are central to some types of ecosystem model that determine which prey are available to predators, but cannot always be measured directly. Deep-sea species are hypothesized to have larger gape sizes than shallower-water species relative to their body size and, because of pronounced adaptive foraging behaviour, show only a weak relationship between gape size and trophic level. Here we present new data describing selective morphological measurements and gape sizes of 134 osteichthyan and chondrichthyan species from the deep sea (200-1300 m) off New Zealand. We describe how gape size (height, width and area) varied with factors including fish size, taxonomy (class and order within a class) and trophic level estimated from stable isotopes. For deep-sea species, there was a strong relationship between gape size and fish size, better predicted by body mass than total length, which varied by taxonomic group. Results show that predictions of gape size can be made from commonly measured morphological variables. No relationship between gape size and trophic level was found, likely a reflection of using trophic level estimates from stable isotopes as opposed to the commonly used estimates from FishBase. These results support the hypothesis that deep-sea fish are generalists within their environment, including suspected scavenging, even at the highest trophic levels.

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