Composition and spatial variability of macroplankton and micronekton within the Antarctic Polar Frontal Zone of the Indian Ocean during austral autumn 1997

Abstract. Data obtained from long-term sediment trap experiments in the Indian Ocean in conjunction with satellite observations illustrate the influence of primary production and the ballast effect on organic carbon flux into the deep sea. They suggest that primary production is the main control on the spatial variability of organic carbon fluxes at most of our study sites in the Indian Ocean, except at sites influenced by river discharges. At these sites the spatial variability of organic carbon flux is influenced by lithogenic matter content. To quantify the impact of lithogenic matter on the organic carbon flux, the densities of the main ballast minerals, their flux rates and seawater properties were used to calculate sinking speeds of material intercepted by sediment traps. Sinking speeds in combination with satellite-derived export production rates allowed us to compute organic carbon fluxes. Flux calculations imply that lithogenic matter ballast increases organic carbon fluxes at all sampling sites in the Indian Ocean by enhancing sinking speeds and reducing the time of organic matter respiration in the water column. We calculated that lithogenic matter content in aggregates and pellets enhances organic carbon flux rates on average by 45 % and by up to 62 % at trap locations in the river-influenced regions of the Indian Ocean. Such a strong lithogenic matter ballast effect explains the fact that organic carbon fluxes are higher in the low-productive southern Java Sea compared to the high-productive western Arabian Sea. It also implies that land use changes and the associated enhanced transport of lithogenic matter from land into the ocean may significantly affect the CO2 uptake of the organic carbon pump in the receiving ocean areas.

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Inertia in physiological traits: Embryonopsis halticella caterpillars (Yponomeutidae) across the Antarctic Polar Frontal Zone

Journal of Insect Physiology ◽

10.1016/j.jinsphys.2004.11.011 ◽

2005 ◽

Vol 51 (1) ◽

pp. 87-97 ◽

Cited By ~ 7

Author(s):

C.J. Klok ◽

S.L. Chown

Keyword(s):

Frontal Zone ◽

Physiological Traits ◽

Polar Frontal Zone ◽

The Antarctic

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Characterization of the Antarctic Polar Frontal Zone to the north of South Georgia in summer 1994

Journal of Geophysical Research Atmospheres ◽

10.1029/97jc00381 ◽

1997 ◽

Vol 102 (C5) ◽

pp. 10483-10497 ◽

Cited By ~ 40

Author(s):

P. N. Trathan ◽

M. A. Brandon ◽

E. J. Murphy

Keyword(s):

Frontal Zone ◽

South Georgia ◽

Polar Frontal Zone ◽

The North ◽

The Antarctic

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Late Miocene vegetation and palaeoenvironments of the Drygalski Formation, Heard Island, Indian Ocean: evidence from palynology

Antarctic Science ◽

10.1017/s0954102005002865 ◽

2005 ◽

Vol 17 (3) ◽

pp. 427-442 ◽

Cited By ~ 10

Author(s):

ELIZABETH M. TRUSWELL ◽

PATRICK G. QUILTY ◽

A. MCMINN ◽

M.K. MACPHAIL ◽

G.E. WHELLER

Keyword(s):

Indian Ocean ◽

Southern Ocean ◽

Late Miocene ◽

Tree Species ◽

Frontal Zone ◽

Tierra Del Fuego ◽

Tree Pollen ◽

Marine Diatoms ◽

Heard Island ◽

The Antarctic

Well sorted, fine lithic sandstone within the Drygalski Formation at Cape Lockyer on the southern tip of Heard Island, preserves a diverse terrestrial palynoflora as well as marine diatoms and a few foraminifera. A combination of these elements suggests a Late Miocene age (10–5 Ma). The palaeovegetation was markedly different from that presently on the island, and appears to comprise at least two ecologically distinct communities: open heath or herbfield dominated by grasses and Asteraceae, and a more mesophytic community dominated by ferns but also including lycopods and angiosperms such as Gunnera. This may have represented a coastal flora similar to the ‘fern-bush’ community that exists now on Southern Ocean islands north of the Antarctic Polar Frontal Zone, and in Tierra del Fuego; however, there is no evidence of tree species in the local flora and trace amounts of tree pollen present may have blown in from other landmasses in the region.

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