Stable Carbon Isotope Studies on the Pecks Cove Mudflat Ecosystem in the Cumberland Basin, Bay of Fundy

1983 ◽  
Vol 40 (S1) ◽  
pp. s262-s272 ◽  
Author(s):  
Peter Schwinghamer ◽  
Francis C. Tan ◽  
Donald C. Gordon Jr.
Keyword(s):  
Carbon Isotope ◽  
Suspended Matter ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
Trophic Levels ◽  
Benthic Diatoms ◽  
Bay Of Fundy ◽  
Intertidal Mudflat ◽  
Relative Importance ◽  
Stable Carbon

Ratios of stable carbon isotopes (δ 13C) have been measured in components of an intertidal mudflat ecosystem located near the head of the Bay of Fundy. Special attention was given to the isolation and analysis of carbon source materials including phytoplankton, benthic algae, marsh grass (Spartina alterniflora), size-fractionated detritus, and "mineral" sediment. Bulk sediment and suspended matter were also analyzed. For most of the year the two major primary producers, Spartina and benthic diatoms (dominated by Gyrosigma spp.), had similar δ 13C values (−13 to −14‰). Some Spartina detritus, presumably "fresh" material, also had similar δ 13C values. It was therefore imposible to estimate the relative importance of carbon from these sources to the nutrition of consumer organisms. Zooplankton, benthic-feeding fish, and benthic fauna had δ 13C values mostly in the range of −12 to −15‰, suggesting that live Spartina, "fresh" detritus, and benthic diatoms could be major carbon sources. Phytoplankton and other isotopically light carbon sources including "aged" detritus, bulk and "mineral" sediment, do not appear to be major carbon sources for mudflat organisms. We found Spartina detritus to be abundant both in sediments and suspended matter outside the salt marshes, but the δ 13C values of most of the detritus were much lighter (−17 to −20‰) than those of live Spartina. The mechanism of this isotopic alteration is not known and we were not able to demonstrate it clearly in laboratory experiments. Although the δ 13C method has helped to assess the relative importance of some isotopically distinct carbon sources, we were unable to detect any 13C enrichment in various trophic levels of mudflat organisms and benthic-feeding fish.Key words: stable carbon isotope ratio, detritus, decomposition, mudflat ecosystem, Pecks Cove, Bay of Fundy

scholarly journals A metaproteomics method to determine carbon sources and assimilation pathways of species in microbial communities

2018 ◽  
Author(s):  
Manuel Kleiner ◽  
Xiaoli Dong ◽  
Tjorven Hinzke ◽  
Juliane Wippler ◽  
Erin Thorson ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Carbon Isotope ◽  
Isotope Ratio ◽  
Single Cells ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
Food Sources ◽  
Individual Species ◽  
Stable Carbon

AbstractMeasurements of the carbon stable isotope ratio (δ13C) are widely used in biology to address major questions regarding food sources and metabolic pathways used by organisms. Measurement of these so called stable carbon isotope fingerprints (SIFs) for microbes involved in biogeochemical cycling and microbiota of plants and animals have led to major discoveries in environmental microbiology. Currently, obtaining SIFs for microbial communities is challenging as the available methods either only provide limited taxonomic resolution, such as with the use of lipid biomarkers, or are limited in throughput, such as NanoSIMS imaging of single cells.Here we present “direct Protein-SIF” and the Calis-p software package (https://sourceforge.net/projects/calis-p/), which enable high-throughput measurements of accurate δ13C values for individual species within a microbial community. We benchmark the method using 20 pure culture microorganisms and show that the method reproducibly provides SIF values consistent with gold standard bulk measurements performed with an isotope ratio mass spectrometer. Using mock community samples, we show that SIF values can also be obtained for individual species within a microbial community. Finally, a case study of an obligate bacteria-animal symbiosis showed that direct Protein-SIF confirms previous physiological hypotheses and can provide unexpected new insights into the symbionts’ metabolism. This confirms the usefulness of this new approach to accurately determine δ13C values for different species in microbial community samples.SignificanceTo understand the roles that microorganisms play in diverse environments such as the open ocean and the human intestinal tract, we need an understanding of their metabolism and physiology. A variety of methods such as metagenomics and metaproteomics exist to assess the metabolism of environmental microorganisms based on gene content and gene expression. These methods often only provide indirect evidence for which substrates are used by a microorganism in a community. The direct Protein-SIF method that we developed allows linking microbial species in communities to the environmental carbon sources they consume by determining their stable carbon isotope signature. Direct Protein-SIF also allows assessing which carbon fixation pathway is used by autotrophic microorganisms that directly assimilate CO2.

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 Carbon sources in the North Sea evaluated by means of radium and stable carbon isotope tracers

2016 ◽  
Vol 61 (2) ◽  
pp. 666-683 ◽  
Author(s):  
W. J. Burt ◽  
H. Thomas ◽  
M. Hagens ◽  
J. Pätsch ◽  
N. M. Clargo ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
North Sea ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
Stable Carbon ◽  
Isotope Tracers ◽  
The North ◽  
The North Sea

scholarly journals Radiocarbon and Stable Carbon Isotope Ratio Data from a 4.7-Mlong Sediment Core of Lake Baikal (Southern Siberia, Russia)

Radiocarbon ◽  
2010 ◽  
Vol 52 (3) ◽  
pp. 1449-1457 ◽  
Author(s):  
Fumiko Watanabe Nara ◽  
Takahiro Watanabe ◽  
Toshio Nakamura ◽  
Takeshi Kakegawa ◽  
Fumitaka Katamura ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Sediment Core ◽  
Lake Baikal ◽  
Transition Period ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
Rapid Change ◽  
Stable Carbon ◽  
Last Glacial ◽  
The Last Glacial

A sediment core (VER99G12; core length, 4.66 m) was taken from the Buguldeika Saddle of Lake Baikal in 1999. Radiocarbon measurements of total organic carbon (TOC) and pollen concentrate fractions from the VER99G12 core were performed by a Tandetron accelerator mass spectrometry (AMS) system (Model-4130, HVEE) at Nagoya University. The AMS 14C ages showed that the VER99G12 core spans the past ∼30 cal ka BP (from the MIS 3 to present), and the average sedimentation rate of this core was calculated to be 13.6 cm/kyr based on the calibrated ages. This means that the time resolution of VER99G12 sediment samples in this study is better than ∼70–80 yr/cm. Stable carbon isotope ratios of TOC (δ13CTOC) in the VER99G12 core varied widely from about 26.6‰ to 31.3‰ during the last glacial/post-glacial transition period (about 17–12 cal ka BP). Therefore, a rapid change in the carbon sources in Lake Baikal occurred in the last glacial/post-glacial transition period is concluded.

scholarly journals Technical Note: Constraining stable carbon isotope values of microphytobenthos (C<sub>3</sub> photosynthesis) in the Arctic for application to food web studies

2013 ◽  
Vol 10 (11) ◽  
pp. 18151-18174 ◽  
Author(s):  
L. E. Oxtoby ◽  
J. T. Mathis ◽  
L. W. Juranek ◽  
M. J. Wooller
Keyword(s):  
Food Web ◽  
Carbon Isotope ◽  
Growth Rates ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
The Arctic ◽  
Stable Carbon ◽  
Marine Food Web ◽  
Carbon Isotopic ◽  
Marine Food

Abstract. Microphytobenthos (MPB) tends to be omitted as a possible carbon source to higher trophic level consumers in high latitude marine food web models that use stable isotopes. Here, we used previously published relationships relating the concentration of aqueous carbon dioxide ([CO2]aq), the stable carbon isotopic composition of dissolved inorganic carbon (DIC) (δ13CDIC), and algal growth rates (μ) to estimate the stable carbon isotope composition of MPB-derived total organic carbon (TOC) (δ13Cp) and fatty acid (FA) biomarkers (δ13CFA). We measured [CO2]aq and δ13CDIC values from bottom water at sampling locations in the Beaufort and Chukchi Seas (n = 18), which ranged from 17 to 72 mmol kg–1 and −0.1 to 1.4 ‰ (0.8 ± 0.4‰, mean ±1 s.d.), respectively. We combined these field measurements with a set of stable carbon isotopic fractionation factors reflecting differences in algal taxonomy and physiology to determine δ13Cp and δ13CFA values. Theδ13Cp and δ13CFA values for a mixed eukaryotic algal community were estimated to be −23.6 ± 0.4‰ and −30.6 ± 0.4‰, respectively. These values were similar to our estimates for Phaeodactylum tricornutum (δ13Cp = −23.9 ± 0.4‰, δ13CFA = −30.9 ± 0.4‰), a pennate diatom likely to be a dominant MPB taxon. Taxon-specific differences were observed between a centric diatom (Porosira glacialis, δ13Cp = −20.0 ± 1.6‰), a marine haptophyte (Emiliana huxleyi, δ13Cp = −22.7 ± 0.5‰), and a cyanobacterium (Synechococcus sp., δ13Cp = −16.2 ± 0.4‰) at μ = 0.1 d−1. δ13Cp and δ13CFA values increased by &amp;simeq; 2.5‰ for the mixed algal consortium and for P. tricornutum when growth rates were increased from 0.1 to 1.4 d−1. We compared our estimates of δ13Cp and δ13CFA values for MPB with previous measurements of δ13CTOC and δ13CFA values for other carbon sources in the Arctic, including ice-derived, terrestrial, and pelagic organic matter. We found that MPB values were significantly distinct from terrestrial and ice-derived carbon sources. However, MPB values overlapped with pelagic sources, which may result in MPB being overlooked as a significant source of carbon in the marine food web.

Amino Acids and Stable Carbon Isotope Distributions in Taihu Lake, China, Over the Last 15,000 Years, and Their Paleoecological Implications

2000 ◽  
Vol 53 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Wang Jinquan ◽  
Liu Jinling
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carbon Isotope ◽  
Organic Nitrogen ◽  
Taihu Lake ◽  
Stable Carbon Isotope ◽  
Carbon Sources ◽  
Stable Carbon ◽  
Amino Acid Contents ◽  
Organic Productivity

AbstractAmino acid, organic nitrogen, and stable carbon isotope (13C/12C) profiles through a core from East Taihu Lake are interpreted in terms of paleoecology and paleoclimate over the last ca. 15,000 yr. Lower amino acid contents and higher δ13C values at the base of the core represent a cool and arid climate, and coincide with low organic productivity. A marked increase in total amino acids and organic nitrogen, with a decrease in δ13C values from 193 to 90 cm (ca. 6500–6000 yr B.P.), indicates a warmer and moist climate, and greater organic productivity. Amino acids then decrease in abundance, while δ13C values increase progressively, beginning at 73 cm (ca. 6000 yr B.P.), reflecting cooling and lower organic productivity. The average δ13C values from a core from West Taihu Lake are evidently higher than values from East Taihu Lake. The latter may reflect a stream environment, whereas the high δ13C values from West Taihu Lake likely reflect autotrophic carbon sources and a lacustrine environment since 11,000 yr B.P.

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