ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Monograph available for loan

Structure and function of contemporary food webs on Arctic shelves : a pan-Arctic comparison (2006)

Wassmann, Paul

New York, NY [u.a.] : Elsevier

add to mindlist on the mindlist

Details Availability

Call number: AWI G2-17-90655

Type of Medium: Monograph available for loan

Pages: S. 123-477 , Ill., graph. Darst., Kt

ISSN: 0079-6611

Series Statement: Progress in oceanography Vol. 71, No. 2-4

Language: English

Note: Contents: Structure and function of contemporary food webs on Arctic shelves: an introduction / P. Wassmann. - Past glacial and interglacial conditions in the Arctic Ocean and marginal seas - a review / D. A. Darby, L. Polyak and H. A. Bauch. - Climate variability and physical forcing of the food webs and the carbon budget on panarctic shelves / E. Carmack, D. Barber, J. Christensen, R. Macdonald, B. Rudels and E. Sakshaug. - Physical and biological characteristics of the pelagic system across Fram Strait to Kongsfjorden / H. Hop, S. Falk-Petersen, H. Svendsen, S. Kwasniewski, V. Pavlov, O. Pavlova and J. E. Søreide. - Food webs and carbon flux in the Barents Sea / P. Wassmann, M. Reigstad, T. Haug, B. Rudels, M. L. Carroll, H. Hop, G. W. Gabrielsen, S. Falk-Petersen, S. G. Denisenko, E. Arashkevich, D. Slagstad and O. Pavlova.

Location: AWI Reading room

Branch Library: AWI Library

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

BOOK

Link to Library Catalog

S·F·X

2

facet.materialart.13

Calibration of sediment traps and particulate organic carbon export using 234Th in the Barents Sea (2002)

Coppola, Laurent ; Roy-Barman, Matthieu ; Wassmann, Paul ; [et al.]

Elsevier BV

Associated volumes

add to mindlist on the mindlist

Details

In: Marine Chemistry, 3664

Description / Table of Contents: Profiles of particulate and dissolved 234Th (t1/2=24.1 days) in seawater and particulate 234Th collected in drifting traps were analyzed in the Barents Sea at five stations during the ALV3 cruise (from June 28 to July 12, 1999) along a transect from 78°15′N–34°09′E to 73°49′N–31°43′E. 234Th/238U disequilibrium was observed at all locations. 234Th data measured in suspended and trapped particles were used to calibrate the catchment efficiency of the sediment traps. Model-derived 234Th fluxes were similar to 234Th fluxes measured in sediment traps based on a steady-state 234Th model. This suggests that the sediment traps were not subject to large trapping efficiency problems (collection efficiency ranges from 70% to 100% for four traps). The export flux of particulate organic carbon (POC) can be calculated from the model-derived export flux of 234Th and the POC/234Th ratio. POC/234Th ratios measured in suspended and trapped particles were very different (52.0±9.9 and 5.3±2.2 μmol dpm−1, respectively). The agreement between calculated and measured POC fluxes when the POC/234Th ratio of trapped particles was used confirms that the POC/234Th ratio in trap particles is representative of sinking particles. Large discrepancies were observed between calculated and measured POC fluxes when the POC/234Th ratio of suspended particles was used. In the Barents Sea, vertical POC fluxes are higher than POC fluxes estimated in the central Arctic Ocean and the Beaufort Sea and lower than those calculated in the Northeast Water Polynya and the Chukchi Sea. We suggest that the latter fluxes may have been strongly overestimated, because they were based on high POC/234Th ratios measured on suspended particles. It seems that POC fluxes cannot be reliably derived from thorium budgets without measuring the POC/234Th ratio of sediment trap material or of large filtered particles.

Type of Medium: 13

ISSN: 0304-4203 , 1872-7581

URL: https://doi.org/10.1016/S0304-4203(02)00071-3

URL: https://cat.telegrafenberg.de/cgi-bin/koha/opac-image.pl?thumbnail=1&imagenumber=850

Language: English

Note: Outline Abstract Keywords 1. Introduction 2. Methods 2.1. Sample collection 2.2. 234Th analyses 2.3. Particulate organic carbon analyses 3. Results 3.1. Hydrography 3.2. Nutrients 3.3. 234Th activities and POC concentrations 3.4. Trapped material 4. Discussion 4.1. Origins of 234Th/238U disequilibrium 4.2. Determining 234Th fluxes 4.3. Calibration of sediment trap with 234Th 4.4. Vertical flux of particulate organic carbon and the POC/234Thp ratio 5. Conclusion Acknowledgements References

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

E-BOOK

Fulltext

3

Electronic Resource

Sea ice algae in the White and Barents seas: composition and origin (2005)

Ratkova, Tatjana N. ; Wassmann, Paul

Oxford, UK : Blackwell Publishing Ltd

Polar research 24 (2005), S. 0

add to mindlist on the mindlist

Details

ISSN: 1751-8369

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography , Geosciences

Notes: To examine algae populations, three expeditions (in March 2001, April 2002 and February 2003) were conducted in the Guba Chupa (Chupa Estuary; north-western White Sea), and one cruise was carried out in the open part of the White Sea in April 2003 and in the northern part of the Barents Sea in July 2001. Sea ice algae and phytoplankton composition and abundance and the content of sediment traps under the land-fast ice in the White Sea and annual and multi-year pack ice in the Barents Sea were investigated. The community in land-fast sea ice was dominated by pennate diatoms and its composition was more closely related to that of the underlying sediments than was the community of the pack ice, which was dominated by flagellates, dinoflagellates and centric diatoms. Algae were far more abundant in land-fast ice: motile benthic and ice-benthic species found favourable conditions in the ice. The pack ice community was more closely related to that of the surrounding water. It originated from plankton incorporation during sea ice formation and during seawater flood events. An additional source for ice colonization may be multi-year ice. Algae may be released from the ice during brine drainage or sea ice melting. Many sea ice algae developed spores before the ice melt. These algae were observed in the above-bottom sediment traps all year around. Three possible fates of ice algae can be distinguished: 1) suspension in the water column, 2) sinking to the bottom and 3) ingestion by herbivores in the ice, at the ice-water interface or in the water column.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/j.1751-8369.2005.tb00143.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Patterns of production and sedimentation in the boreal and polar Northeast Atlantic (1991)

WASSMANN, PAUL ; PEINERT, ROLF ; SMETACEK, VICTOR

Oxford, UK : Blackwell Publishing Ltd

Polar research 10 (1991), S. 0

add to mindlist on the mindlist

Details

ISSN: 1751-8369

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Geography , Geosciences

Notes: Pelagic systems are potentially capable of retaining and recycling all autochthonous organic material, although some losses due to sinking particles inevitably occur. Relating processes in the surface layers quantitatively to vertical particle flux is difficult because only a small percentage of the total production is lost annually via sinking in the open ocean. Further, only a few types of particles contribute to this flux and only a smalt proportion of these may actually reach greater depths.Measurements of vertical flux with sediment traps revealed seasonal and regional patterns also within the northwestern Atlantic and indicate imbalances between particle formation and degradation. The classical pattern of spring bloom sedimentation followed by reduced loss rates has been found in shelf and shallow water regions such as the Norwegian Coastal Current and fjords and is also encountered in the Barents Sea. In the Norwegian Sea. however, the seasonal pattern appears different as the seasonal maximum has been observed during late summer/autumn.The physical environment determines nutrient availability and hence the particles potentially available for sedimentation. The relationship between phyto- and zooplankton governs vertical flux seasonality, and zooplankters with different life cycles and feeding strategies further modify the principle patterns. Herbivores with life-cycle strategies involving overwintering of large biomass and predictable seasonal appearance (copepods, cuphausiids) will have a different impact than opportunistic organisms with very low overwintering biomass, for example salps and ptcropods. The latter exhibit much greater intcrannual biomass variation and may thus contribute to intcrannual variability of the vertical flux. Shelf systems of similar latitude arc generally comparable with respect to their flux patterns and also share similarities with marginal ice zones. Open ocean systems as the Norwegian Sea, however, exhibit different patterns which are similar to the subarctic Pacific.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/j.1751-8369.1991.tb00647.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

Retention versus export food chains: processes controlling sinking loss from marine pelagic systems (1997)

Wassmann, Paul

Springer

Hydrobiologia 363 (1997), S. 29-57

add to mindlist on the mindlist

Details

ISSN: 1573-5117

Keywords: export and retention food chains ; vertical flux ; top-downregulation ; zooplankton ; global carbon flux

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract The role of export and retention food chains forpelagic-benthic coupling is considered by evaluatingdifferent food chain scenarios and processes such asaggregation, grazing and zooplankton-mediated fluxes.The consequences of grazing of primary production bydifferent zooplankton for the vertical export ofparticulate organic matter from the euphotic zone arediscussed. Reference is made to existing data andalgorithms regarding primary production and verticalexport of carbon from the euphotic zone, both onannual and daily time scales. Examples regarding therole of nutrient addition, removal of pelagiccarnivores and zooplankton grazing for vertical fluxare presented. It is speculated how variable grazingimpact of micro- and mesozooplankton, as well asherbivorous, omnivorous and carnivorous feedingstrategies of mesozooplankton could compete withaggregation during phytoplankton blooms and influenceexport fluxes. It is concluded that the transport ofparticulate organic matter to depth not only dependson bottom-up regulation as determined by physicalforcing, but also on the structure and function of theprevailing planktonic food web. Scenarios arepresented which indicate that top-down regulationplays a pivotal role for the regulation of verticalflux. This conclusion may have crucial consequencesfor future biogeochemical programmes investigatingpelagic-benthic coupling in the ocean. The endeavoursof many research programmes are dominated by lines ofthought where straightforward biogeochemistry andbottom-up regulation is the focus. Phyto- andzooplankton as well as process-oriented researchactivities have to be the focal point of futureresearch if the current comprehension of export fromand retention in the upper layers is going to makedistinct progress.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1003113403096

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

Nutrient runoff and transfer from land and rivers to the Gulf of Riga (1999)

Stålnacke, Per ; Vagstad, Nils ; Tamminen, Timo ; [et al.]

Springer

Hydrobiologia 410 (1999), S. 103-110

add to mindlist on the mindlist

Details

ISSN: 1573-5117

Keywords: nutrients ; Gulf of Riga ; agricultural runoff ; riverine loads ; marine eutrophication

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract In this paper, we have synthesized and integrated results regarding nutrient loads and eutrophication of the Gulf of Riga (GoR) that were obtained in three projects that were part of a six-year research programme (1993–1998). In particular, we focused our attention on the factors that control the temporal variability in the load of nutrients in the drainage basin and rivers, as well as the effects of such nutrients on the environment of the recipient, the Gulf of Riga. The results indicate that the rivers play a crucial role in the total input of nutrients to the GoR, and exceed the combined contribution from atmospheric deposition, point emissions from cities and industries along the coast, and nitrogen fixation by marine organisms. It was found that natural variability in water discharge was the main factor controlling the temporal variability in the riverine load of nutrients (i.e. differences in load between seasons and years). Moderate nutrient losses to surface waters, especially from agriculture, and weak riverine response to the sudden decrease in agricultural production after the disintegration of the Soviet Union in the early 1990s were also found. It is suggested that this is most likely related to the inertia in, and buffering capacity of, agricultural soils, i.e. depending of factors such as hydrological conditions, the size of ground water aquifers and water-saturated soils, creating favourable conditions for nutrient retention processes in the agricultural landscape. Regardless of the relatively low area-specific riverine inputs, the pollution loads in the rivers have contributed significantly to eutrophication of the Gulf of Riga. This seems to be true despite the relatively rapid distribution of the loads beyond the littoral zone of the gulf, resulting in a moderate all-over eutrophication of the entire recipient, characteried by a continuously shifting gradient between the southern and northern parts of the gulf. Furthermore, the marine eutrophication seems to be less prominent and less confined to the southernmost basin than previously assumed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1003736620843

Permalink