Changes in the δ<sup>13</sup>C of surface water particulate organic matter across the subtropical convergence in the SW Indian Ocean

François, Roger; Altabet, Mark A.; Goericke, Ralf; McCorkle, Daniel C.; Brunet, Christian; Poisson, Alain

doi:10.1029/93gb01277

Cited by 252 publications

(297 citation statements)

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“…Temperature has only a minor influence on isotope fractionation between gaseous and dissolved CO 2 [Vogel et al, 1970] and anyway large regional variations in the d 13 C of dissolved CO 2 have already been ruled out [Rau et al, 1982[Rau et al, , 1989. True, temperature influences dissolved CO 2 solubility and therefore concentrations [Rau et al, 1989;Goericke and Fry, 1994] and it affects phytoplankton growth rates and the expression of carbon isotope fractionation [Rau et al, 1992[Rau et al, , 1996François et al, 1993;Goericke and Fry, 1994;Laws et al, 1995;Dehairs et al, 1997] in ways that might translate into variability in the d 13 C of organic matter. But SSTs reconstructed via diatombased transfer functions for the three sediment core sites reported here indicate little variation in temperature between these sites.…”

Section: Resultsmentioning

confidence: 99%

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

et al. 2008

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[1] Measurements of d 13 C, d 15 N, and C/N on diatom-bound organic matter were made over the Holocene and Last Glacial Maximum (LGM) from three sediment cores in the Southern Ocean, one each from the Atlantic, Indian, and Pacific sectors. The site in the Scotia Sea (Atlantic sector) differed considerably from the other two sites by having markedly lower d 13 C, more variable d 15 N and C/N ratios, and a sedimentary diatom assemblage that was never dominated by Fragilariopsis kerguelensis. Although environmental parameters certainly have a strong impact on the isotope ratios, d 13 C is also correlated to the proportion of F. kerguelensis in the three cores investigated here (r 2 = 0.8). Extreme values of d 13 C, d 15 N, and C/N at the Last Glacial Maximum were also related to the abundance of winter stages of Eucampia antarctica. These results suggest that diatom specific isotope records should be interpreted in conjunction with information on the species composition of the samples.

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Section: Resultsmentioning

confidence: 99%

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

et al. 2008

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“…Lower-latitude plankton food bases have higher d 13 C values relative to higher-latitude waters in the Southern Ocean and the geographical range Stable isotope signature of cephalopod beaks Y. Cherel & K. A. Hobson 1605 between Antarctica, Kerguelen and the subtropics spans a natural gradient in d 13 C values in marine waters (François et al 1993). Hence, the very negative d 13 C value of S. circumantarctica, which is identical to that of the endemic Antarctic P. glacialis, strongly suggests that the species grew in Antarctic waters before migrating to the Kerguelen area.…”

Section: Discussion (A) Methodological Commentsmentioning

confidence: 99%

“…Beaks from avian predators were fresh items, not accumulated items, thus indicating that squids were caught in Kerguelen waters, as were fish prey. To help the investigation of feeding areas of cephalopods, the isotopic signatures of species spanning a latitudinal gradient in stable isotopes (François et al 1993) were used. These control species were one Antarctic squid from Adélie Land (Psychroteuthis glacialis), two endemic Kerguelen octopuses (Benthoctopus thielei and Graneledone gonzalezi) and one subtropical octopus from Amsterdam Island.…”

Section: Methodsmentioning

confidence: 99%

Stable isotopes, beaks and predators: a new tool to study the trophic ecology of cephalopods, including giant and colossal squids

2005

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Cephalopods play a key role in the marine environment but knowledge of their feeding habits is limited by lack of data. Here, we have developed a new tool to investigate their feeding ecology by combining the use of their predators as biological samplers together with measurements of the stable isotopic signature of their beaks. Cephalopod beaks are chitinous hard structures that resist digestion and the stable isotope ratios of carbon (d 13 C) and nitrogen (d 15 N) are indicators of the foraging areas and trophic levels of consumers, respectively. First, a comparison of d 13 C and d 15 N values of different tissues from the same individuals showed that beaks were slightly enriched in 13 C but highly impoverished in 15 N compared with lipid-free muscle tissues. Second, beaks from the same species showed a progressive increase in their d 15 N values with increasing size, which is in agreement with a dietary shift from lower to higher trophic levels during cephalopod growth. In the same way, there was an increase in the d 15 N signature of various parts of the same lower beaks in the order rostrum, lateral walls and wings, which reflects the progressive growth and chitinization of the beaks in parallel with dietary changes. Third, we investigated the trophic structure of a cephalopod community for the first time. Values of d 15 N indicate that cephalopods living in slope waters of the subantarctic Kerguelen Islands (nZ18 species) encompass almost three distinct trophic levels, with a continuum of two levels between crustacean-and fish-eaters and a distinct higher trophic level occupied by the colossal squid Mesonychoteuthis hamiltoni. d 13 C values demonstrated that cephalopods grow in three different marine ecosystems, with 16 species living and developing in Kerguelen waters and two species migrating from either Antarctica (Slosarczykovia circumantarctica) or the subtropics (the giant squid Architeuthis dux). The stable isotopic signature of beaks accumulated in predators' stomachs therefore revealed new trophic relationships and migration patterns and is a powerful tool to investigate the role of the poorly known cephalopods in the marine environment.

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“…1982Rau et al, . , 1989Francois et al, 1993 . Phytoplankton and zooplankton collected from the Ž . surface Southern Ocean waters SST s 88C were 5‰ lower in d 13 C compared to the samples collected from the warm regions where pCO concentrations 2 Ž .…”

Section: Comparison Of D 13 C Signatures In Plankton and Sediments Ofmentioning

confidence: 99%

Radiocarbon and stable carbon isotope compositions of organic compound classes in sediments from the NE Pacific and Southern Oceans

Wang

Druffel

2001

Marine Chemistry

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AbstractŽ 14 .Ž 13 . Radiocarbon D C abundance and stable carbon isotope d C compositions were measured for total lipid, total Ž . Ž . hydrolyzable amino acids THAA , total carbohydrates TCHO , and acid-insoluble organic fractions separated from Ž . phytoplankton, zooplankton, and sediment cores collected from two abyssal sites, one in the northeast NE Pacific Ocean and one in the Southern Ocean. These results are compared with those obtained for a separate core from the NE Pacific and w Ž . In contrast, sediment from the Southern Ocean had much lower TOC and D 14 C values, which indicated that organic matter was extremely refractory. Sedimentation rates calculated from 14 C ages of TOC for both sites indicate that the differences in the organic composition and D 14 C signatures of organic matter in the sediments likely resulted from the differences in production and deposition of organic matter to the sediment, and the diagenetic stages of sedimentary organic matter in the two oceans. 14 Ž 13 . Unlike D C, stable carbon isotopic d C compositions of TOC in the sediments of the two oceans had similar values, which reflect not only the organic matter input from marine-derived sources but also the nature of degraded, predominately uncharacterized organic fraction in these sediments. The differences in d 13 C values among the compound classes in sediments at both sites can be attributed to the carbon isotopic signatures in original sources during photosynthesis and associated environmental factors. Preferential degradation of organic matter and heterotrophic effects may also play important roles for the observed d 13 C variations and these effects need to be further investigated. q 2001 Elsevier Science B.V. All rights reserved. -C. Wang, E.R.M. Druffelr Marine Chemistry 73 2001 65-81 66

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Changes in the δ¹³C of surface water particulate organic matter across the subtropical convergence in the SW Indian Ocean

Cited by 252 publications

References 56 publications

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

Stable isotopes, beaks and predators: a new tool to study the trophic ecology of cephalopods, including giant and colossal squids

Radiocarbon and stable carbon isotope compositions of organic compound classes in sediments from the NE Pacific and Southern Oceans

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Changes in the δ13C of surface water particulate organic matter across the subtropical convergence in the SW Indian Ocean

Cited by 252 publications

References 56 publications

Diatom δ13C, δ15N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

Diatom δ13C, δ15N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

Stable isotopes, beaks and predators: a new tool to study the trophic ecology of cephalopods, including giant and colossal squids

Radiocarbon and stable carbon isotope compositions of organic compound classes in sediments from the NE Pacific and Southern Oceans

Contact Info

Product

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Changes in the δ¹³C of surface water particulate organic matter across the subtropical convergence in the SW Indian Ocean

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition

Diatom δ¹³C, δ¹⁵N, and C/N since the Last Glacial Maximum in the Southern Ocean: Potential impact of Species Composition