Analysenautomat zur simultanen Mikrobestimmung von C, H und N

Monar, Irene

doi:10.1007/bf01239145

Cited by 25 publications

(18 citation statements)

References 26 publications

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“…The water was prefiltered with a 200 Km mesh, and a measured volume of between 100 and 900 ml, depending on particulate load, was immediately filtered through a pre-ashed (400 "C for 6 h) 25 mm Whatman GF/F filter by gentle hand-pump filtration. Filters were oven-dried at 50°C for 3 d and combusted in a Heraeus CHNMikro Universal combustion analyser calibrated with cyclohexanone (Monar 1972). Unused, pre-ashed filters were analysed as carbon and nitrogen blanks.…”

Section: Methodsmentioning

confidence: 99%

Carbon and nitrogen resources available to kelp bed filter feeders in an upwelling environment

Fielding¹,

Davis²

1989

Mar. Ecol. Prog. Ser.

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ABSTRACT. Environmental variables, and summer and winter particulate concentrations in the water column of a kelp bed in an upwelling region on the western Cape coast of South Africa, were measured daily to assess short-term fluctuations. There were significant differences between the summer and winter upwelling index, water temperature and wave height. Summer part~culate carbon and nitrogen concentrations of 533 11g 1-' and 66 pg 1-' respectively were lower than winter levels of 764 pg C 1-' and 79 pg N 1-'. However, summer upwelling events did not reduce particulate carbon and nitrogen to the very low levels that might be expected from previous studies of chlorophyll concentrations in the kelp bed. Large waves resulted in C:N ratios that were significantly hlgher in winter than in summer @ < 0.01), and during continuous winter downwelling, a large proportion of the particulate material in the water column was of macrophyte rather than phytoplankton origin. In summer the carbon and nitrogen load was most highly correlated with temperature, while wind and wave size were the most important factors affecting particulate concentrations in winter. Mean particulate organic concentrations were 380 big C I-' and 43 pg N I-' and these compare weU with concentrations of 301 k~g C 1-' and 4 1 pg N 1-' estimated from previous primary production studies. The estimated carbon demands of Choromytilus meridjonalis and Aulacomya ater, 2 mussels that commonly occur in kelp beds on the west coast, could be met in winter and summer by the particulate organic component in the kelp bed water column. Particulate nitrogen resources probably meet most of the nitrogen requirements of the 2 mussels.

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Section: Methodsmentioning

confidence: 99%

Carbon and nitrogen resources available to kelp bed filter feeders in an upwelling environment

Fielding¹,

Davis²

1989

Mar. Ecol. Prog. Ser.

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“…After drying at 60 "C the filter was submitted to CHN analysis. This was done using a Heraeus CHN-Mikro Universal Combustion Analyser (model CHN-RAPID) calibrated with cyclohexane (Monar, 1972).…”

Section: Methodsmentioning

confidence: 99%

Particulate organic matter in a mountain stream in the south-western Cape, South Africa

et al. 1987

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The quality and quantity of allochthonous inputs and of benthic organic matter were investigated in a secondorder, perennial mountain stream in the south-west Cape, South Africa, between April 1983 and January 1986. Although the endemic, riparian vegetation is sclerophyllous, low and evergreen, inputs of allochthonous detritus to the stream (434 to 500 g m-2y-1) were similar to those recorded for riparian communities worldwide, as were calorific values of these inputs (9548 to 10 032 KJ mm2y-'). Leaf fall of the riparian vegetation is seasonal, occurring in spring (November) as discharge decreases, resulting in retention of benthic organic matter (BOM) on the stream bed during summer and early autumn (maximum 224 g me2). Early winter rains (May) scoured the stream almost clean of benthic detritus (winter minimum 8 g mm2). Therefore, BOM was predictably plentiful for about half of each year and predictably scarce for the other half. Coarse BOM (CBOM) and fine BOM (FBOM) constituted 46 -64% of BOM standing stock, ultra-fine BOM (UBOM) 16 -33 070 and leaf packs 13 -24%. The mean annual calorific value of total BOM standing stock was 1709 KJ me2. Both standing stocks and total calorific values of BOM were lower than those reported for streams in other biogeographical regions. Values of C:N ratios decreased with decrease in BOM particle size with no seasonal trends. The stream is erosive with a poor ability to retain organic detritus. Its character appears to be dictated by abiotic factors, the most important of which is winter spates.

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“…Samples of 200ml seawater were filtered through 25mm Whatman GF/F filters which had been previously ashed at 450 "C for 6 h. The filters from samples which had been filtered in the field were stored on ice and then oven-dried at 50°C for 12 h before being analysed with a Heraeus elemental analyser using cyclohexanone (10.14 % N; 51.79 % C) as a standard (Monar 1972).…”

Section: Methodsmentioning

confidence: 99%

Particle clearance and yield in relation to bacterioplankton and suspended particulate availability in estuarine and open coast populations of the mussel Mytilus edulis

Lucas¹,

Newell²,

Shumway³

et al. 1987

Mar. Ecol. Prog. Ser.

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Measurements were made of resource availabihty and the filtration rate and particle retention efficiency of mussels M y t h s edulis L. from an estuarine site on the River Lynher and from an open coastal site at Whitsand Bay, Cornwall, UK. Small cocci of 0.25 km, large cocci of 0.56 pm and small rods of 0.725 pm mean spherical diameter comprised 87 % of the free-living bacterial population at Whitsand Bay and 86% in the Lynher estuary during September 1984. Free-living bacteria represented only 5 % of the carbon and 9.7 and 11 3 O/O respectively of the nitrogen potentially available for exploitation as a food resource in the water column at the estuanne and open coast sites. Weightspecific clearance rate of particles > 12.7 km diameter by M. edulis from the Lynher estuary was approximately 2.5 1 g-' h-' at 14'C whdst that for mussels from Whltsand Bay was 2.6 1 g-' h-'. Relative retention efficiency of particles was generally similar for mussels from the 2 sites, declining to ca 28 O/O for natural bacterioplankton of 0.513 to 0.524 pm mean spherical diameter. These results suggest no significant intraspecific differences in filtration rates or relatlve particle retention efficiencies, for mussels from the 2 sites, in spite of major differences in partlcle concentrations at the sites. Although ca 65 O/O of the natural bacterioplankton were cleared from the expenmental vessels after 335 min at 14 'C, carbon and nitrogen yield from bacterioplankton at natural concentrations is likely to be small. The complete particle spectrum, represented by living phytoplankton cells, detritus and bacterioplankton, would need to be exploited by the Whitsand Bay population of mussels to sustain carbon and nitrogen demands since the total yleld from all particulate size classes was only 713 ug C h-' and 78 pg N h-' compared with an estimated minimum requirement of 737 pg C h-' and 45.5 ug N h-'. The total carbon and nitrogen resource in the Lynher estuary was well in excess of the estimated requirements of the mussels. However, it is estimated that the free-living bacterial resource would contribute only 4.2 % to the carbon budget and 17 % to the nitrogen budget of the Lynher estuary mussels compared with 1.6 and 7 % respectively of that of the open coast mussels. These results suggest that mussels from both the estuarine and coastal sites utilize phytoplankton or similar sized particles as a primary nutritional resource, although in other systems where bacterial standing stocks are high relative to other particulate resources, bacterioplankton may make a more important contribution to the carbon and nitrogen requirements of filter-feedmg organisms.

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Analysenautomat zur simultanen Mikrobestimmung von C, H und N

Cited by 25 publications

References 26 publications

Carbon and nitrogen resources available to kelp bed filter feeders in an upwelling environment

Carbon and nitrogen resources available to kelp bed filter feeders in an upwelling environment

Particulate organic matter in a mountain stream in the south-western Cape, South Africa

Particle clearance and yield in relation to bacterioplankton and suspended particulate availability in estuarine and open coast populations of the mussel Mytilus edulis

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