Krill and salp faecal pellets contribute equally to the carbon flux at the Antarctic Peninsula

AbstractKrill and salps are important for carbon flux in the Southern Ocean, but the extent of their contribution and the consequences of shifts in dominance from krill to salps remain unclear. We present a direct comparison of the contribution of krill and salp faecal pellets (FP) to vertical carbon flux at the Antarctic Peninsula using a combination of sediment traps, FP production, carbon content, microbial degradation, and krill and salp abundances. Salps produce 4-fold more FP carbon than krill, but the FP from both species contribute equally to the carbon flux at 300 m, accounting for 75% of total carbon. Krill FP are exported to 72% to 300 m, while 80% of salp FP are retained in the mixed layer due to fragmentation. Thus, declining krill abundances could lead to decreased carbon flux, indicating that the Antarctic Peninsula could become a less efficient carbon sink for anthropogenic CO2 in future.

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Movements of southern elephant seals

Canadian Journal of Zoology ◽

10.1139/z96-163 ◽

1996 ◽

Vol 74 (8) ◽

pp. 1485-1496 ◽

Cited By ~ 72

Author(s):

B. J. McConnell ◽

M. A. Fedak

Keyword(s):

Southern Ocean ◽

Continental Shelf ◽

Antarctic Peninsula ◽

Average Rate ◽

Stationary Phases ◽

Mirounga Leonina ◽

Elephant Seals ◽

South Georgia ◽

Southern Elephant Seals ◽

The Antarctic

Twelve southern elephant seals (Mirounga leonina) were tracked for an average of 119 days as they left their breeding or moulting beaches on the island of South Georgia between 1990 and 1994. Females travelled either eastward up to 3000 km away to the open Southern Ocean or to the continental shelf on or near the Antarctic Peninsula. Males either stayed close to South Georgia or used South Georgia as a base for shorter trips. The females all left South Georgia in a directed manner at an average rate of 79.4 km/day over at least the first 15 days. Thereafter travel was interrupted by bouts of slower travel or stationary phases. The latter were localized at sites on the continental shelf or along its edge. Three seals that were tracked over more than one season repeated their outward direction of travel and used some of the same sites in subsequent years. The magnitude of the movements makes most of the Southern Ocean potentially available to elephant seals.

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A description and summary of the Antarctic Humpback Whale Catalogue

J. Cetacean Res. Manage. ◽

10.47536/jcrm.vi.307 ◽

2020 ◽

pp. 95-99

Author(s):

Judith Allen ◽

Carole Carlson ◽

Peter T. Stevick

Keyword(s):

South America ◽

Southern Ocean ◽

Antarctic Peninsula ◽

Humpback Whale ◽

Humpback Whales ◽

Western Coast ◽

Long Distance ◽

Dorsal Fin ◽

Feeding Area ◽

The Antarctic

The Antarctic Humpback Whale Catalogue (AHWC) is an international collaborative project investigating movement patterns of humpback whales in the Southern Ocean and corresponding lower latitude waters. The collection contains records contributed by 261 researchers and opportunistic sources. Photographs come from all of the Antarctic management areas, the feeding grounds in southern Chile and also most of the known or suspected low-latitude breeding areas and span more than two decades. This allows comparisons to be made over all of the major regions used by Southern Hemisphere humpback whales. The fluke, left dorsal fin/flank and right dorsal fin/flank collections represent 3,655, 413 and 407 individual whales respectively. There were 194 individuals resighted in more than one year, and 82 individuals resighted in more than one region. Resightings document movement along the western coast of South America and movement between the Antarctic Peninsula and western coast of South America and Central America. A single individual from Brazil was resighted off South Georgia, representing the first documented link between the Brazilian breeding ground and any feeding area. A second individual from Brazil was resighted off Madagascar, documenting long distance movement of a female between non-adjacent breeding areas. Resightings also include two matches between American Samoa and the Antarctic Peninsula, documenting the first known feeding site for American Somoa and setting a new long distance seasonal migration record. Three matches between Sector V and eastern Australia support earlier evidence provided by Discovery tags. Multiple resightings of individuals in the Antarctic Peninsula during more than one season indicate that humpback whales in this area show some degree of regional feeding area fidelity. The AHWC provides a powerful non-lethal and non-invasive tool for investigating the movements and population structure of the whales utilising the Southern Ocean Sanctuary. Through this methodical, coordinated comparison and maintenance of collections from across the hemisphere, large-scale movement patterns may be examined, both within the Antarctic, and from the Antarctic to breeding grounds at low latitudes.

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Coccolithophore populations and their contribution to carbonate export during an annual cycle in the Australian sector of the Antarctic zone

Biogeosciences ◽

10.5194/bg-15-1843-2018 ◽

2018 ◽

Vol 15 (6) ◽

pp. 1843-1862 ◽

Cited By ~ 7

Author(s):

Andrés S. Rigual Hernández ◽

José A. Flores ◽

Francisco J. Sierro ◽

Miguel A. Fuertes ◽

Lluïsa Cros ◽

...

Keyword(s):

Southern Ocean ◽

Ocean Acidification ◽

Deep Ocean ◽

Sediment Traps ◽

Global Ocean ◽

Field Observations ◽

Scotia Sea ◽

Allochthonous Species ◽

Circumpolar Current ◽

The Antarctic

Abstract. The Southern Ocean is experiencing rapid and relentless change in its physical and biogeochemical properties. The rate of warming of the Antarctic Circumpolar Current exceeds that of the global ocean, and the enhanced uptake of carbon dioxide is causing basin-wide ocean acidification. Observational data suggest that these changes are influencing the distribution and composition of pelagic plankton communities. Long-term and annual field observations on key environmental variables and organisms are a critical basis for predicting changes in Southern Ocean ecosystems. These observations are particularly needed, since high-latitude systems have been projected to experience the most severe impacts of ocean acidification and invasions of allochthonous species. Coccolithophores are the most prolific calcium-carbonate-producing phytoplankton group playing an important role in Southern Ocean biogeochemical cycles. Satellite imagery has revealed elevated particulate inorganic carbon concentrations near the major circumpolar fronts of the Southern Ocean that can be attributed to the coccolithophore Emiliania huxleyi. Recent studies have suggested changes during the last decades in the distribution and abundance of Southern Ocean coccolithophores. However, due to limited field observations, the distribution, diversity and state of coccolithophore populations in the Southern Ocean remain poorly characterised. We report here on seasonal variations in the abundance and composition of coccolithophore assemblages collected by two moored sediment traps deployed at the Antarctic zone south of Australia (2000 and 3700 m of depth) for 1 year in 2001–2002. Additionally, seasonal changes in coccolith weights of E. huxleyi populations were estimated using circularly polarised micrographs analysed with C-Calcita software. Our findings indicate that (1) coccolithophore sinking assemblages were nearly monospecific for E. huxleyi morphotype B/C in the Antarctic zone waters in 2001–2002; (2) coccoliths captured by the traps experienced weight and length reduction during summer (December–February); (3) the estimated annual coccolith weight of E. huxleyi at both sediment traps (2.11 ± 0.96 and 2.13 ± 0.91 pg at 2000 and 3700 m) was consistent with previous studies for morphotype B/C in other Southern Ocean settings (Scotia Sea and Patagonian shelf); and (4) coccolithophores accounted for approximately 2–5 % of the annual deep-ocean CaCO3 flux. Our results are the first annual record of coccolithophore abundance, composition and degree of calcification in the Antarctic zone. They provide a baseline against which to monitor coccolithophore responses to changes in the environmental conditions expected for this region in coming decades.

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Seasonally Resolved Proxy Data From the Antarctic Peninsula Support a Heterogeneous Middle Eocene Southern Ocean

Paleoceanography and Paleoclimatology ◽

10.1029/2019pa003581 ◽

2019 ◽

Author(s):

Emily J. Judd ◽

Linda C. Ivany ◽

Robert M. DeConto ◽

Anna Ruth W. Halberstadt ◽

Nicole M. Miklus ◽

...

Keyword(s):

Southern Ocean ◽

Antarctic Peninsula ◽

Middle Eocene ◽

Proxy Data ◽

The Antarctic

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Stratigraphy of Antarctic late Cenozoic pectinid-bearing deposits

Antarctic Science ◽

10.1017/s0954102098000212 ◽

1998 ◽

Vol 10 (2) ◽

pp. 161-170 ◽

Cited By ~ 20

Author(s):

H.A. Jonkers

Keyword(s):

Southern Ocean ◽

Food Availability ◽

Habitat Loss ◽

Antarctic Peninsula ◽

East Antarctica ◽

Combined Effects ◽

Late Cenozoic ◽

Late Pliocene ◽

Antarctic Waters ◽

The Antarctic

Antarctic late Cenozoic pectinid-bearing sedimentary strata are chiefly confined to localities in the northern part of the Antarctic Peninsula, in the McMurdo Sound area, and Marine Plain, East Antarctica. Ages of these deposits range from Oligocene to Holocene. Chlamys-like scallops, which are absent from today's Southern Ocean, thrived in Antarctic waters during both glacial and interglacial episodes, but disappeared during the Late Pliocene. Their extinction is believed to result from the combined effects of increased carbonate solubility, habitat loss and limitations in food availability, associated with major cooling.

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