Origins and fate of dissolved sterols in the Weddell Sea, Antarctica

Mühlebach, Anneke; Weber, Kurt

doi:10.1016/s0146-6380(98)00097-7

Cited by 27 publications

(13 citation statements)

References 29 publications

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“…The ratio of sterols in SCEs to total sterols in dietary phytoplankton was estimated to be less than a few percent based on the ratio of SCEs to chlorophylls in fecal pellets and the chlorophylls : sterol ratio in phytoplankton (Parsons et al 1984), consistent with the estimation of Mühlebach and Weber (1998) Table 1. Compositions of sterols (mole %) in dietary green algae (Chlorella, Scendesmus, Stigeoclonium) and of SCE sterols in fecal pellets of Daphnia magna fed on Chlorella (n ϭ 1) and Scendesmus (n ϭ 1), and those in fecal pellets of Asellus hilgendorfi fed on Scendesmus (n ϭ 2) and Stigeoclonium (n ϭ 2) 17.1 0 SCE, steryl chlorin ester; C 27 ∆ 5,22 , cholesta-5, 22-dien-3 -ol; C 27 ∆ 5 , cholest-5-en-3 -ol; C 28 ∆ 5,7,22 , 24-methylcholesta-5, 7,22-trien-3 -ol; C 28 ∆ 5,22 , 24-methylcholesta-5, 22-dien-3 -ol; C 28 ∆ 5,24 , 24-methylcholesta-5, 24-dien-3 -ol; C 28 ∆ 5 , 24-methylcholest-5-en-3 -ol; C 28 ∆ 7 , 24-methylcholest-7-en-3 -ol; C 29 ∆ 5,22 , 24-ethylcholesta-5, 22-dien-3 -ol; C 29 ∆ 7,22 , 24-ethylcholesta-7, 22-dien-3 -ol; C 29 ∆ 5,24 , 24-ethylcholesta-5, 24-dien-3 -ol; C 29 ∆ 5 , 24-ethylcholest-5-en-3 -ol; C 29 ∆ 7 , 24-ethylcholest-7-en-3 -ol reported compositions of sterols in SCEs fairly well reflect the compositions in dietary phytoplankton (Harradine et al 1996b, Pearce et al 1998, Talbot et al 1999a, we presume that the selectivity in the ester-bonding formation in SCEs does not change significantly among sterols in grazers.…”

Section: Resultssupporting

confidence: 62%

“…Mass spectra were collected by scanning from m/z 50-550 with scan time 0.5 s and electron energy 70 eV. TMSi-sterols were identified by retention times and by comparing the mass spectra with the literature (Kondo et al 1991;Mühlebach and Weber 1998). Available standard samples of sterols are limited; therefore, the relative abundances of sterols were calculated from the relative intensities of m/z 129, a characteristic and common fragment ion of TMSi-sterols, assuming that the specific intensities of m/z 129 of the sterols are the same as that of cholesterol.…”

Section: Methodsmentioning

confidence: 99%

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Sterol composition of steryl chlorin esters (SCEs) formed through grazing of algae by freshwater crustaceans: relevance to the composition of sedimentary SCEs

et al. 2005

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In a laboratory experiment, we studied the composition of sterols in steryl chlorin esters (SCEs) egested in fecal pellets of freshwater crustaceans (Daphnia magna and Asellus hilgendorfi) fed on a single green algae (Chlorella, Scendesmus, or Stigeoclonium) or on phytoplankton collected from a shallow pond abundant in diatoms. Both unaltered sterols present in dietary phytoplankton and sterols formed by metabolism in crustaceans were incorporated in the SCEs. C 27 sterols except for cholesterol (C 27 ∆ 5 ) and C 28 sterols, major sterols in diatoms, were scarce in the SCEs compared with those in the dietary algae, whereas cholesterol, which could be formed by crustacean metabolism, was relatively abundant in the SCEs. Therefore, the contribution of diatoms to the total phytoplankton population would be underestimated if diatom-specific C 27 and C 28 sterols in sedimentary SCEs were used in estimations as biomarkers of diatoms.

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Section: Resultssupporting

confidence: 62%

Section: Methodsmentioning

confidence: 99%

Sterol composition of steryl chlorin esters (SCEs) formed through grazing of algae by freshwater crustaceans: relevance to the composition of sedimentary SCEs

et al. 2005

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“…Sterols were identified by retention times, sterol standards and mass spectra. For further details about the method see Mühlebach &Weber (1998). While the FID was routinely used as a detector, the proportions of nearly coeluting sterols, e.g.…”

Section: Methodsmentioning

confidence: 99%

On the trophic fate of Phaeocystis pouchetii. VII. Sterols and fatty acids reveal sedimentation of P. pouchetii-derived organic matter via krill

Hamm¹,

Reigstad²,

Riser³

et al. 2001

Mar. Ecol. Prog. Ser.

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As part of a joint project on the fate of phytoplankton in Balsfjorden in Northern Norway, we investigated the trophic fate and sedimentation potential of Phaeocystis pouchetii by tracing the transition of biomarker patterns from a phytoplankton bloom to sediment traps and during a gutpassage experiment. The phytoplankton biomass during the spring bloom 1996 was dominated by colonial P. pouchetii (ca 85%) and 4 members of the diatom family Thalassiosiraceae (ca 10%). Particulate organic carbon in sediment traps largely consisted of fecal material from the Arctic krill Thysanoessa sp. Sterol and fatty acid biomarker patterns in the phytoplankton bloom could be reproduced by combining the individual biomarker patterns of the isolated phytoplankters P. pouchetii and Thalassiosira decipiens in a ratio of ca 75:25. In a laboratory experiment, Arctic krill (Thysanoessa raschii) fed with similar efficiency on P. pouchetii colonies and the Thalassiosiraceae. During gut passage, the abundance of Thalassiosiraceae biomarkers in fecal strings increased relative to P. pouchetii biomarkers, while biomarkers from krill became dominant. This transition of biomarker patterns due to gut passage in T. raschii closely resembled the biomarker transition from the surface bloom to material in sediment traps at 40 to 170 m depth, which was mainly composed of krill fecal strings. We conclude that krill grazed efficiently on P. pouchetii colonies in Balsfjorden and caused sedimentation of P. pouchetii-derived organic matter below the euphotic zone via fecal strings. Hence, both transfer to higher trophic levels and sedimentation of Phaeocystis spp.-derived organic matter can be more effective than is commonly believed. KEY WORDS: Phaeocystis · Diatoms · Krill · Trophic fate · Vertical flux · BiomarkersResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 209: 55-69, 2001 rates of recognizable Phaeocystis spp. colonies and cells are low (Wassmann 1994 and references therein, Andreassen &Wassmann 1998). In contrast, the sudden disappearance of Phaeocystis spp. blooms from the euphotic zone, the existence of nitrate-depleted, silicate-rich water bodies with low phytoplankton concentrations in the vicinity of Phaeocystis spp. blooms (Wassmann et al. 1990, Smith et al. 1991, and the occurrence of pigments and dimethylsulphoniopropionate (DMSP) typical of Phaeocystis spp. in deeper layers and the sediment (di Tullio et al. 1996(di Tullio et al. , 2000 have suggested efficient sedimentation of Phaeocystis spp.-derived organic matter to aphotic zones in spite of the low sedimentation potential of Phaeocystis spp. aggregates (Riebesell 1993, Passow & Wassmann 1994, Riebesell et al. 1995.Arctic krill were argued to be largely responsible for the vertical flux of particulate organic carbon in Balsfjorden, where krill feces dominated sedimentation during Phaeocystis pouchetii blooms (Lutter et al. 1990, Riebesell et al. 1995. The resulting proposition that krill grazed efficiently on P. pouch...

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“…Thus 'dissolved' organic species reservoir cannot be neglected in organic production or other biological activities, as 'dissolved' compounds can be incorporated rapidly into the sedimentation process through absorption, bioaccumulation and bioaggregation (Laureillard and Saliot 1993). It is well known that sterols remain in particular matter in sediments and as suspended solids in the water column (Tolosa et al 2003;Wang et al 2004;Sangiorgi et al 2005 (Gagosian 1975;Muhlebach and Weber 1998). Thus sterol fingerprinting in dissolved organic matter of natural aqueous samples have been applied recently to trace their origins (Jeanneau et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Tracing origins of sewage and organic matter using dissolved sterols in Masan and Haengam Bay, Korea

Hong¹,

Kim²,

Ha³

et al. 2011

Ocean Sci. J.

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Masan and Haengam Bays in Korea are highly polluted and semi-enclosed. Domestic and industrial effluents are directly or indirectly discharged into the bays through sewage treatment plants (STP) and creeks. In this study, 15 dissolved sterol compounds were determined in order to understand their sources and relative contribution. Freshwater samples were taken from 13 creeks and at two STP sites on a monthly basis. Total dissolved sterol concentrations ranged from 993 to 4158 ng/L. The concentrations of sterols in winter were higher than in summer. Among the sterols analyzed, cholesterol, β-sitosterol, coprostanol and cholestanone were major compounds in creek water. Seawater samples were concurrently collected at 21 stations in Masan Bay. Total sterol concentrations ranged 118-6,956 ng/L. Inner bay showed high concentrations of sterols in summer, while outer bay showed high sterol concentrations in winter. Among the sterols, cholesterol, β-sitosterol and brassicasterol were major compounds in seawater. In order to examine the contribution of urban sewage, the concentration of coprostanol and fecal sterol ratios were calculated. Most of the creek water, inner bay and near STP outlet samples were affected by sewage. Terrestrial organic matters accounted for a high proportion of dissolved organic matter origin. Fecal origins were relatively high in the inner bay areas and in the STP outlet, while sterols of marine origin were high in the outer bay areas.

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Origins and fate of dissolved sterols in the Weddell Sea, Antarctica

Cited by 27 publications

References 29 publications

Sterol composition of steryl chlorin esters (SCEs) formed through grazing of algae by freshwater crustaceans: relevance to the composition of sedimentary SCEs

Sterol composition of steryl chlorin esters (SCEs) formed through grazing of algae by freshwater crustaceans: relevance to the composition of sedimentary SCEs

On the trophic fate of Phaeocystis pouchetii. VII. Sterols and fatty acids reveal sedimentation of P. pouchetii-derived organic matter via krill

Tracing origins of sewage and organic matter using dissolved sterols in Masan and Haengam Bay, Korea

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