Sulfur isotopes (δ34S) in Arctic marine mammals: indicators of benthic vs. pelagic foraging

2020 ◽  
Vol 653 ◽  
pp. 205-216
Author(s):  
P Szpak ◽  
M Buckley
Keyword(s):  
Marine Mammals ◽  
Sulfur Isotope ◽  
Foraging Ecology ◽  
Sulfur Isotopes ◽  
Stable Carbon Isotope ◽  
Ringed Seal ◽  
Trophic Levels ◽  
Bone Collagen ◽  
The Arctic ◽  
Stable Carbon

Consumer tissue stable carbon isotope compositions (δ13C) are well established indicators of benthic and pelagic foraging in marine ecosystems. Stable sulfur isotope compositions (δ34S) are also potentially useful in this regard but have not been widely utilized outside of estuaries and salt marsh ecosystems. To test the ability of δ13C and δ34S to reflect benthic and pelagic foraging, we analyzed the stable carbon, nitrogen (δ15N), and sulfur isotope compositions of bone collagen from walrus (an obligate benthic feeder) and ringed seal (a mixed benthic/pelagic feeder) sampled from across the North American Arctic. Both had relatively low δ34S values compared to those typically observed in marine consumers. These data suggest an important role for benthic microalgae in coastal marine food webs in the Arctic. At all of the 10 locations where both taxa could be sampled, walrus had lower δ34S values than ringed seal, suggesting that this measurement is a useful indicator of benthic and pelagic foraging in nearshore Arctic environments. Contrary to expectations, there were no consistent differences in δ13C between walrus and ringed seal at any of these sites, suggesting that this measurement may not always be best interpreted in light of benthic vs. pelagic foraging, particularly when comparisons are made across trophic levels. When the foraging ecology of a consumer is unknown, our data suggest that δ34S may be a more sensitive indicator of the relative importance of benthic and pelagic prey in the diet than δ13C.

scholarly journals Stable Carbon Isotope Measurements on Hair from Wild Animals from Altiplanic Environments of Jujuy, Argentina

Radiocarbon ◽  
2002 ◽  
Vol 44 (3) ◽  
pp. 709-716 ◽  
Author(s):  
Héctor O Panarello ◽  
C Jorge Fernández
Keyword(s):  
Stable Carbon Isotopes ◽  
Stable Carbon Isotope ◽  
Trophic Levels ◽  
Bone Collagen ◽  
Wild Animals ◽  
Stable Carbon ◽  
Animal Tissues ◽  
Isotopic Study ◽  
The Andes ◽  
Different Types

The use of stable carbon isotopes as dietary tracers is an application that is widening its scope within the fields of ecology and paleoecology. Although hair is potentially one of the most favorable animal tissues for isotopic measurement for dietary studies, this tissue is rarely included in research works. This may be due to the fact that many aspects related to hair tissue are not fully understood, especially in the case of wild animals whose diets consist of plants with contrasting 13C/12C ratios, their abundance depending on seasonality. The present isotopic study of hair from animals inhabiting the Andes in northwestern Argentina, at heights ranging from 3500 to about 5000 m above sea level (asl) shows that 1) δ13C values measured on hair from herbivores with a mixed and isotopically contrasting diet, and from their carnivorous predators, differ in their respective trophic levels, 2) in primary consumers, different types of hair from the same individual have different δ13C values, whereas hair values are homogeneous in carnivores, and 3) some types of hair from rodents, such as whiskers, show δ13C values similar to those of less metabolically active tissues such as bone collagen.

A study of food chains in seagrass communities. III. Stable carbon isotope ratios

1985 ◽  
Vol 36 (5) ◽  
pp. 683 ◽  
Author(s):  
PD Nichols ◽  
DW Klumpp ◽  
RB Johns
Keyword(s):  
Carbon Isotope ◽  
Opposite Effect ◽  
Stable Carbon Isotope ◽  
Benthic Algae ◽  
Trophic Levels ◽  
Food Chains ◽  
Stable Carbon ◽  
Commercial Fish ◽  
Δ13c Values ◽  
Stable Carbon Isotope Ratios

Stable carbon isotope determinations have been used to obtain a general background to food chains being studied by a range of chemical and biological techniques. δ13C values indicate that animals (δ13CC - 11.4‰ to - 14.9‰), including two locally important commercial fish, Platycephalus laevigatus (rock flathead) and Hyporhamphus melanochir (southern sea garfish), from the Corner Inlet seagrass and non-seagrass communities are dependent to varying degrees upon seagrass (δ13C - 7.0‰ to - 9.3‰) and benthic algae for their carbon source. The largest changes in δ13C values in the food chains is at the point involving seagrasses and their direct herbivores. The latter have more negative δ13C values (H. melanochir - 12.1%o, isopods - 11.4%o). Little or no change in δ13C values is apparent at the higher trophic levels (carnivores - 13 .0‰ to - 14.9‰). Epiphytic material on the fresh leaves of the two seagrass species in the Inlet is depleted in 13C when compared with the seagrass leaves. An opposite effect is observed for epiphytic material on Posidonia australis detritus.

scholarly journals Diet and association of Pontonia pinnophylax occurring in Pinna nobilis: insights from stable isotope analysis

2001 ◽  
Vol 81 (1) ◽  
pp. 177-178 ◽  
Author(s):  
H. Kennedy ◽  
C.A. Richardson ◽  
C.M. Duarte ◽  
D.P. Kennedy
Keyword(s):  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Carbon Sources ◽  
Posidonia Oceanica ◽  
Mantle Cavity ◽  
Trophic Levels ◽  
Stable Carbon ◽  
Pinna Nobilis ◽  
Wide Range ◽  
Sea Grass

Stable carbon isotope measurements (δ13C) were used to assess the sources of carbon assimilated by the fan mussel Pinna nobilis, in sea grass Posidonia oceanica meadows, and an associated shrimp Pontonia pinnophylax which occurs within this bivalve's mantle cavity. The primary carbon sources available to both animals displayed a wide range of δ13C values, from −12·3 to −22·3‰. The δ13C and δ15N of Pinna nobilis and Pontonia pinnophylax suggest that they assimilate carbon from similar sources, occupy comparable trophic levels and that their association is commensal.

Understanding specifics in generalist diets of carnivorans by analyzing stable carbon isotope values in Pleistocene mammals of Florida

Paleobiology ◽  
10.1666/13055 ◽  
2014 ◽  
Vol 40 (3) ◽  
pp. 477-493 ◽  
Author(s):  
Robert S. Feranec ◽  
Larisa R. G. DeSantis
Keyword(s):  
Food Webs ◽  
Carbon Isotope ◽  
Prey Species ◽  
Tooth Enamel ◽  
Stable Carbon Isotope ◽  
Trophic Levels ◽  
Trophic Relationships ◽  
Stable Carbon ◽  
Generalist Diet ◽  
Ancient Food

Within ancient ecosystems, it is generally difficult to determine the specific diets of species from higher trophic levels, which in turn hinders our understanding of trophic relationships and energy flow through these systems. To better understand the ecology of taxa at higher trophic levels, we used analysis of tooth enamel stable carbon isotope values to infer the dietary preferences of Canis edwardii and Smilodon gracilis from the Leisey Shell Pit 1A (LSP 1A) and Inglis 1A, two Pleistocene localities in Florida. The goals of the analyses were to (1) determine whether these carnivorans specialized in particular prey types or maintained a generalist diet; (2) ascertain whether carbon isotope values support what was previously suggested about the ecology of these species; and (3) establish what ecological details of ancient food webs can be discovered by carbon isotope analyses at higher trophic levels. Results show that the sampled carnivoran carbon isotope values are distributed among suspected prey isotope values, suggesting that varied prey were taken at the study localities. Prey compositions were modeled for each carnivoran species by using Stable Isotope Analysis in R (SIAR). The modeled diets indicate that each studied carnivoran had a generalist diet; however, there are differences in how these taxa achieved dietary generalization. At the glacial Inglis 1A locality, sampled individuals of C. edwardii and S. gracilis show similar isotope values and modeled dietary prey proportions, although both carnivorans do show a preference for grazing prey species. The similar isotopic values, and calculated prey proportions, observed between these species may imply greater interspecific competition for food. At the interglacial LSP 1A locality, C. edwardii shows values similar to those observed at Inglis 1A. In contrast, the data for S. gracilis shows a preference for consuming browsing prey species. Further, its restricted range of carbon isotope values suggests that S. gracilis may have concentrated its feeding within a particular habitat. Examination of stable carbon isotope values among species at higher trophic levels reveals that some intricacies of ancient food webs can be discerned.

scholarly journals Consensus δ13C Values

Radiocarbon ◽  
1984 ◽  
Vol 26 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Richard Burleigh ◽  
Keith Matthews ◽  
Morven Leese
Keyword(s):  
Carbon Isotope ◽  
Stable Carbon Isotope ◽  
Mean Value ◽  
Bone Collagen ◽  
Natural Material ◽  
Base Line ◽  
Stable Carbon ◽  
Plant Materials ◽  
Animal Bone ◽  
The Mean

Selected stable carbon isotope measurements published in Radiocarbon over a 12-year period have been abstracted, plotted, and summarized, to give more reliable estimates of the mean value and range of δ13C for five classes of natural material (human bone collagen, non-human animal bone collagen, plant materials, wood, and charcoal), and to provide a firmer base line for stable carbon isotope dietary and environmental studies.

scholarly journals Combining δ13C and δ15N from bone and dentine in marine mammal palaeoecological research: insights from toothed whales

2021 ◽  
Author(s):  
Alba Rey-Iglesia ◽  
Tess Wilson ◽  
Jennifer Routledge ◽  
Mikkel Skovrind ◽  
Eva Garde ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Marine Mammals ◽  
Mammalian Species ◽  
Population Level ◽  
Bone Collagen ◽  
Correction Factors ◽  
Stable Carbon ◽  
Δ13c And Δ15n ◽  
Toothed Whale ◽  
Isotope Ratio Mass Spectrometer

Rationale Stable carbon (δ13C) and nitrogen (δ15N) isotope compositions of bone and dentine collagen extracted from subfossil specimens of extinct and extant mammalian species have been widely used to study the paleoecology of past populations. Due to possible systematic differences in stable isotope values between bone and dentine, dentine values can be transformed into bone-collagen equivalent using a correction factor. This approach has been applied to terrestrial species, but correction factors specifically for marine mammals are lacking. Here, we provide correction factors to transform dentine δ13C and δ15N values into bone-collagen equivalent for two toothed whale sister species: narwhal and beluga. Methods We sampled bone and tooth dentine from the skulls of 11 narwhals and 26 belugas. In narwhals, dentine was sampled from tusk and embedded tooth; in beluga, dentine was sampled from tooth. δ13C and δ15N were measured using an elemental analyzer coupled to a continuous flow isotope ratio mass spectrometer. Intraindividual bone and dentine isotopic compositions were used to calculate correction factors for each species, and to translate dentine isotopic values into bone-collagen equivalent. Results Our analysis revealed differences in δ13C and δ15N between bone and dentine. In narwhals, we found (i) lower average δ13C in bone compared with dentine from tusk and embedded tooth; (ii) no difference in dentine δ13C between tusk and embedded tooth; (iii) lower average δ15N in bone compared with dentine, with the highest values found in embedded tooth. For belugas, we also detected lower δ13C and δ15N in bone compared with tooth dentine. Conclusions Based on our analysis, we provide bone/dentine correction factors for narwhals (both at species and population level), and for belugas. The correction factors, when applied to dentine δ13C and δ15N values, enable the combined analysis of stable isotope data from bone and dentine.

scholarly journals Porewater <i>δ</i><sup>13</sup>C<sub>DOC</sub> indicates variable extent of degradation in different talik layers of coastal Alaskan thermokarst lakes

2021 ◽  
Vol 18 (7) ◽  
pp. 2241-2258
Author(s):  
Ove H. Meisel ◽  
Joshua F. Dean ◽  
Jorien E. Vonk ◽  
Lukas Wacker ◽  
Gert-Jan Reichart ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Greenhouse Gas ◽  
Carbon Isotope ◽  
Lake Sediment ◽  
Stable Carbon Isotope ◽  
The Arctic ◽  
High Porosity ◽  
Stable Carbon ◽  
Thermokarst Lakes ◽  
Wide Range

Abstract. Thermokarst lakes play an important role in permafrost environments by warming and insulating the underlying permafrost. As a result, thaw bulbs of unfrozen ground (taliks) are formed. Since these taliks remain perennially thawed, they are zones of increased degradation where microbial activity and geochemical processes can lead to increased greenhouse gas emissions from thermokarst lakes. It is not well understood though to what extent the organic carbon (OC) in different talik layers below thermokarst lakes is affected by degradation. Here, we present two transects of short sediment cores from two thermokarst lakes on the Arctic Coastal Plain of Alaska. Based on their physiochemical properties, two main talik layers were identified. A “lake sediment” is identified at the top with low density, sand, and silicon content but high porosity. Underneath, a “taberite” (former permafrost soil) of high sediment density and rich in sand but with lower porosity is identified. Loss on ignition (LOI) measurements show that the organic matter (OM) content in the lake sediment of 28±3 wt % (1σ, n=23) is considerably higher than in the underlying taberite soil with 8±6 wt % (1σ, n=35), but dissolved organic carbon (DOC) leaches from both layers in high concentrations: 40±14 mg L−1 (1σ, n=22) and 60±14 mg L−1 (1σ, n=20). Stable carbon isotope analysis of the porewater DOC (δ13CDOC) showed a relatively wide range of values from −30.74 ‰ to −27.11 ‰ with a mean of -28.57±0.92 ‰ (1σ, n=21) in the lake sediment, compared to a relatively narrow range of −27.58 ‰ to −26.76 ‰ with a mean of -27.59±0.83 ‰ (1σ, n=21) in the taberite soil (one outlier at −30.74 ‰). The opposite was observed in the soil organic carbon (SOC), with a narrow δ13CSOC range from −29.15 ‰ to −27.72 ‰ in the lake sediment (-28.56±0.36 ‰, 1σ, n=23) in comparison to a wider δ13CSOC range from −27.72 ‰ to −25.55 ‰ in the underlying taberite soil (-26.84±0.81 ‰, 1σ, n=21). The wider range of porewater δ13CDOC values in the lake sediment compared to the taberite soil, but narrower range of comparative δ13CSOC, along with the δ13C-shift from δ13CSOC to δ13CDOC indicates increased stable carbon isotope fractionation due to ongoing processes in the lake sediment. Increased degradation of the OC in the lake sediment relative to the underlying taberite is the most likely explanation for these differences in δ13CDOC values. As thermokarst lakes can be important greenhouse gas sources in the Arctic, it is important to better understand the degree of degradation in the individual talik layers as an indicator for their potential in greenhouse gas release, especially, as predicted warming of the Arctic in the coming decades will likely increase the number and extent (horizontal and vertical) of thermokarst lake taliks.

scholarly journals ECOLOGICAL AND ENVIRONMENTAL-PHYSIOLOGICAL RESEARCHES OF PINNIPEDS OF BARENTS, WHITE AND KARA SEAS IN 2015–2019

2020 ◽  
Vol 11 (4) ◽  
pp. 198-214
Author(s):  
N.N. Kavtsevich ◽  
◽  
I.A. Erokhina ◽  
V.N. Svetochev ◽  
O.N. Svetocheva ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Satellite Telemetry ◽  
Ringed Seal ◽  
Harp Seal ◽  
The Arctic ◽  
Bearded Seal ◽  
Arctic Seas ◽  
Physiological Studies

A brief review of the most significant ecological and environmental-physiological studies of three species of true seals living in the arctic seas is presented. The results were obtained on the basis of the analysis of materials from the expeditions of Marine Mammals Laboratory in the Barents, White and Kara seas in 2015–2019. Special attention is paid to the application of satellite telemetry as well as hematological,biochemical, cytochemical methods in the study of harp seal, ringed seal, bearded seal.

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