Trophic Enrichment Factors of Carbon and Nitrogen Isotopic Ratios (Δ13C and Δ15N) in Four Marine Ciliates

Understanding the magnitude and causes of isotopic fractionation between organisms and their dietary resources is crucial for gaining knowledge on stable isotope ecology. However, little is known regarding the diet-tissue fractionation values of marine ciliates, which play a critical role in the reconstruction of microbial food webs. In the present study, we conducted experiments on two benthic (Pseudokeronopsis pararubra and Protocruzia labiata) and two pelagic (Strombidium sulcatum and Uronemella filificum) marine ciliates, where they were fed with isotopically constant foods (Chaetoceros calcitrans and Isochrysis galbana) under laboratory culture conditions to determine their carbon and nitrogen isotopic fractionation values (Δ13C and Δ15N). The stable isotope values (δ13C and δ15N) of ciliates for all experiments rapidly increased after the initial feeding, with half-lives ranging from 6.1 to 23.0h for δ13C and from 3.1 to 24.9h for δ15N. The Δ13C and Δ15N for all ciliates represented significantly positive enrichments, with overall mean fractionations of 0.6±0.2 and 1.2±0.4, respectively. Irrespective of the dietary type, both Δ13C and Δ15N were very similar for the same ciliate species. These results suggest that Δ13C and Δ15N for marine ciliates are similar to those found in common marine organisms with very little food-dependent variation. Overall, quantifying the specific isotopic fractionation of marine ciliates is expected to provide fundamental information on the trophic transfer of carbon, nitrogen, and energy flow through the microbial pathway in marine ecosystems.

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Effects of light intensity, water velocity, and species composition on carbon and nitrogen stable isotope ratios in periphyton

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-075 ◽

1998 ◽

Vol 55 (8) ◽

pp. 1919-1925 ◽

Cited By ~ 62

Author(s):

Neil A MacLeod ◽

David R Barton

Keyword(s):

Stable Isotope ◽

Light Intensity ◽

Isotopic Fractionation ◽

Water Velocity ◽

Benthic Boundary Layer ◽

Low Light ◽

Small Stream ◽

Isotopic Signatures ◽

Carbon And Nitrogen ◽

Stable Isotope Fractionation

Periphyton was allowed to grow on glass plates suspended in the water column of a small stream under two conditions of light and water velocity, over two seasons, to assess the influence of the thickness of benthic boundary layers on stable isotope fractionation. Isotopic signatures for both carbon and nitrogen in samples of periphyton varied with light intensity and season, but not with current velocity. In summer, periphyton grown under low-light conditions had depleted 13C and 15N values relative to periphyton grown under high light. In autumn, isotopic signatures were generally more depleted than in summer, but did not vary systematically with light intensity or water velocity. These results suggest that isotopic fractionation in periphyton was more strongly influenced by the intensity of metabolic activity than by variations in the thickness of the benthic boundary layer.

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Stable carbon and nitrogen isotopic fractionation between diet and swine tissues

Scientia Agricola ◽

10.1590/s0103-90162006000600012 ◽

2006 ◽

Vol 63 (6) ◽

pp. 579-582 ◽

Cited By ~ 23

Author(s):

Gabriela Bielefeld Nardoto ◽

Patricia Barboza de Godoy ◽

Epaminondas Sansigolo de Barros Ferraz ◽

Jean Pierre Henry Balbaud Ometto ◽

Luiz Antonio Martinelli

Keyword(s):

Stable Isotope ◽

Isotopic Fractionation ◽

Isotope Ratios ◽

Animal Nutrition ◽

Stable Carbon ◽

Carbon And Nitrogen ◽

Dietary Reconstruction ◽

Naturally Occurring ◽

C And N ◽

The One

Naturally occurring stable isotope ratios can be a powerful tool in studies of animal nutrition, provided that the assumptions required for dietary reconstruction are validated by studies such as the one presented here. The objective of this study was to document the magnitude of isotopic fractionation between swine diet and their different tissues. For this, the isotopic ratios of carbon and nitrogen of the diet and selected tissues (hair, nail, liver, muscle, fat and cartilage) were determined. The delta13C and delta15N of the diet were -15.9‰ and 1.3‰, respectively, and all delta15N of swine tissues were 2.2 to 3.0‰ enriched in 15N in relation to the diet. Little variation in delta15N occurred among tissues, with exception to liver that was less enriched in 15N than the nail. Nail and hair presented no 13C enrichment relative to diet. Cartilage was ~1.0‰ enriched in 13C as compared to diet. Liver and muscle were on average 2.1‰ more depleted in 13C in relation to diet as well as fat tissues. Some of the C and N isotope ratios of swine tissues differed in organs, but the isotopic fractionation trends among tissues appears to be similar to other mammals. Therefore our data provide a good baseline to interpret stable isotope patterns in domestic mammals (such as swine) in controlled or semi-controlled experiments.

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Identification of the production system of beef cattle by the stable isotope analysis

Pesquisa Agropecuária Brasileira ◽

10.1590/s1678-3921.pab2020.v55.01501 ◽

2020 ◽

Vol 55 ◽

Author(s):

Alexandre Perdigão ◽

Cyntia Ludovico Martins ◽

Luiz Carlos Vieira Junior ◽

Maria Márcia Pereira Sartori ◽

Maria Betânia Niehues ◽

...

Keyword(s):

Stable Isotope ◽

Beef Cattle ◽

Production Systems ◽

Isotopic Ratio ◽

Cattle Production ◽

Classification Rate ◽

Δ13c And Δ15n ◽

Carbon And Nitrogen ◽

Tropical Conditions ◽

Beef Cattle Production

Abstract: The objective of this work was to evaluate the potential of the stable isotope technique to characterize beef cattle production systems in tropical conditions. For this, carbon and nitrogen stable isotopes were identified in non-defatted and defatted bovine muscles. A total of 45 cattle were evaluated in three production systems: pasture, conventional feedlot, and young beef bull feedlot (n = 15 per system). Samples from the Trapezius cervicis, Longissimus dorsi, and Semitendinosus muscles were collected to determine the isotopic composition of δ13C and δ15N. The isotopic data of the δ13C and δ15N of non-defatted and defatted muscles were subjected to the principal component analysis (PCA) and to the discriminant analysis (DA). The PCA allowed separating the three production systems based on the results obtained for the non-defatted and defatted muscles. A correct global classification rate of 100% and a cross-validation rate of 100% were obtained with the DA. The carbon and nitrogen isotopic ratio of non-defatted and defatted muscles allows for the precise identification of beef cattle production systems in tropical conditions.

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Investigating Intra-Individual Dietary Changes and 14C Ages Using High-Resolution δ13C and δ15N Isotope Ratios and 14C Ages Obtained from Dentine Increments

Radiocarbon ◽

10.2458/azu_rc.57.18338 ◽

2015 ◽

Vol 57 (4) ◽

pp. 665-677 ◽

Cited By ~ 8

Author(s):

Laura G van der Sluis ◽

Paula J Reimer ◽

Niels Lynnerup

Keyword(s):

High Resolution ◽

Stable Isotope ◽

Isotope Analysis ◽

Permanent Teeth ◽

Nitrogen Stable Isotope ◽

Δ13c And Δ15n ◽

Dietary Changes ◽

Carbon And Nitrogen ◽

Single Tooth

Ten medieval permanent teeth were subjected to incremental dentine sectioning and stable isotope analysis to investigate dietary changes in high resolution. In addition to this, eight increments were also selected for radiocarbon measurements to examine possible intra-individual age differences. Results reveal the cessation of weaning, various dietary profiles, and in some cases significantly different 14C ages obtained from a single tooth. This case study illustrates how 14C measurements can function as a proxy alongside the commonly used carbon and nitrogen stable isotope values to interpret the diet of past individuals.

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Carbon and nitrogen dynamics in the coastal Japan Sea inferred from 15 years of measurements of stable isotope ratios of Calanus sinicus

10.5194/os-2021-74 ◽

2021 ◽

Author(s):

Ken-ichi Nakamura ◽

Atsushi Nishimoto ◽

Saori Yasui-Tamura ◽

Yoichi Kogure ◽

Misato Nakae ◽

...

Keyword(s):

Stable Isotope ◽

Japan Sea ◽

Isotope Ratios ◽

Stable Isotope Ratios ◽

Interannual Variations ◽

Calanus Sinicus ◽

Δ13c And Δ15n ◽

Δ13c Values ◽

Carbon And Nitrogen ◽

The Japan Sea

Abstract. Human activities have caused sometimes dramatic changes to the marine environment globally and locally during the last half century. We hypothesized that the carbon and nitrogen stable isotope ratios (δ13C and δ15N) of the copepod Calanus sinicus, one of the dominant secondary producers of North Pacific coastal waters, would record anthropogenic impacts on the coastal environment of the Japan Sea. We monitored these isotope ratios during the spring at four stations in the Japan Sea from 2006 to 2020. The δ13C values ranged from −24.7 ‰ to −15.0 ‰ and decreased from the spring bloom (February/March) to the post-bloom (June/July). This monthly variation was attributed to changes in both the physiology of C. sinicus and phytoplankton δ13C. The negative correlation between the δ13C values of C. sinicus and their carbon:nitrogen ratios reflected lipid accumulation by the copepods; high δ13C values were associated with high sea surface chlorophyll a concentrations. The δ15N values ranged from 2.8 ‰ to 8.8 ‰. The tendency of the δ15N values to increase from the bloom to post-bloom was attributable to an increase of the δ15N of the phytoplankton associated with nitrate depletion and Rayleigh fractionation. These monthly changes were synchronized among the four stations, but δ13C and δ15N differed significantly between stations. Interannual variations were statistically significant, but there were no significant monotonic trends. Interannual variations differed between δ13C and δ15N as well as among stations. These results suggest that local conditions rather than global-scale trends were the primary determinants of elemental cycles in this coastal ecosystem.

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TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b93b4af8c32.73166623 ◽

2017 ◽

Author(s):

Sosuke Otani ◽

Akira Umehara ◽

Haruka Miyagawa ◽

...

Keyword(s):

Stable Isotope ◽

Secondary Production ◽

Isotope Ratios ◽

Ruditapes Philippinarum ◽

Transfer Efficiency ◽

Food Sources ◽

Stable Isotope Ratios ◽

Primary Producers ◽

Nitrogen Stable Isotope ◽

Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

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