Phytoplankton production characteristics in the southern Atlantic and the Atlantic sector of the Southern Ocean in the austral summer of 2009–2010

Oceanology ◽  
2012 ◽  
Vol 52 (2) ◽  
pp. 206-218 ◽  
Author(s):  
A. B. Demidov ◽  
S. A. Mosharov ◽  
V. I. Gagarin
Keyword(s):  
Southern Ocean ◽  
Austral Summer ◽  
Phytoplankton Production ◽  
Atlantic Sector ◽  
Production Characteristics

Distribution of iodide and iodate in the Atlantic sector of the southern ocean during austral summer

2011 ◽  
Vol 58 (25-26) ◽  
pp. 2733-2748 ◽  
Author(s):  
K. Bluhm ◽  
P.L. Croot ◽  
O. Huhn ◽  
G. Rohardt ◽  
K. Lochte
Keyword(s):  
Southern Ocean ◽  
Austral Summer ◽  
Atlantic Sector

scholarly journals Large-scale spatial variabilities in the humpback whale acoustic presence in the Atlantic sector of the Southern Ocean

2020 ◽  
Vol 7 (12) ◽  
pp. 201347
Author(s):  
Elena Schall ◽  
Karolin Thomisch ◽  
Olaf Boebel ◽  
Gabriele Gerlach ◽  
Stefanie Spiesecke ◽  
...  
Keyword(s):  
Southern Ocean ◽  
High Latitude ◽  
Large Scale ◽  
Austral Summer ◽  
Humpback Whale ◽  
Humpback Whales ◽  
Stock Management ◽  
Atlantic Sector ◽  
Acoustic Activity ◽  
Passive Acoustic

Southern Hemisphere humpback whales ( Megaptera novaeangliae ) inhabit a wide variety of ecosystems including both low- and high-latitude areas. Understanding the habitat selection of humpback whale populations is key for humpback whale stock management and general ecosystem management. In the Atlantic sector of the Southern Ocean ( ASSO ), the investigation of baleen whale distribution by sighting surveys is temporally restricted to the austral summer. The implementation of autonomous passive acoustic monitoring, in turn, allows the study of vocal baleen whales year-round. This study describes the results of analysing passive acoustic data spanning 12 recording positions throughout the ASSO applying a combination of automatic and manual analysis methods to register humpback whale acoustic activity. Humpback whales were present at nine recording positions with higher acoustic activities towards lower latitudes and the eastern and western edges of the ASSO . During all months, except December (the month with the fewest recordings), humpback whale acoustic activity was registered in the ASSO . The acoustic presence of humpback whales at various locations in the ASSO confirms previous observations that part of the population remains in high-latitude waters beyond austral summer, presumably to feed. The spatial and temporal extent of humpback whale presence in the ASSO suggests that this area may be used by multiple humpback whale breeding populations as a feeding ground.

Distribution and demography of Antarctic krill in the Southeast Atlantic sector of the Southern Ocean during the austral summer 2008

Polar Biology ◽  
2010 ◽  
Vol 33 (7) ◽  
pp. 957-968 ◽  
Author(s):  
B. A. Krafft ◽  
W. Melle ◽  
T. Knutsen ◽  
E. Bagøien ◽  
C. Broms ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Antarctic Krill ◽  
Austral Summer ◽  
Atlantic Sector

scholarly journals Modelled estimates of spatial variability of iron stress in the Atlantic sector of the Southern Ocean

2017 ◽  
Vol 14 (17) ◽  
pp. 3883-3897 ◽  
Author(s):  
Thomas J. Ryan-Keogh ◽  
Sandy J. Thomalla ◽  
Thato N. Mtshali ◽  
Hazel Little
Keyword(s):  
Southern Ocean ◽  
Primary Production ◽  
Austral Summer ◽  
Production Model ◽  
Photosynthetic Parameters ◽  
Atlantic Sector ◽  
Mean Values ◽  
Biogeochemical Models ◽  
The Absolute ◽  
Iron Addition

Abstract. The Atlantic sector of the Southern Ocean is characterized by markedly different frontal zones with specific seasonal and sub-seasonal dynamics. Demonstrated here is the effect of iron on the potential maximum productivity rates of the phytoplankton community. A series of iron addition productivity versus irradiance (PE) experiments utilizing a unique experimental design that allowed for 24 h incubations were performed within the austral summer of 2015/16 to determine the photosynthetic parameters αB, PBmax and Ek. Mean values for each photosynthetic parameter under iron-replete conditions were 1.46 ± 0.55 (µg (µg Chl a)−1 h−1 (µM photons m−2 s−1)−1) for αB, 72.55 ± 27.97 (µg (µg Chl a)−1 h−1) for PBmax and 50.84 ± 11.89 (µM photons m−2 s−1) for Ek, whereas mean values under the control conditions were 1.25 ± 0.92 (µg (µg Chl a)−1 h−1 (µM photons m−2 s−1)−1) for αB, 62.44 ± 36.96 (µg (µg Chl a)−1 h−1) for PBmax and 55.81 ± 19.60 (µM photons m−2 s−1) for Ek. There were no clear spatial patterns in either the absolute values or the absolute differences between the treatments at the experimental locations. When these parameters are integrated into a standard depth-integrated primary production model across a latitudinal transect, the effect of iron addition shows higher levels of primary production south of 50° S, with very little difference observed in the subantarctic and polar frontal zone. These results emphasize the need for better parameterization of photosynthetic parameters in biogeochemical models around sensitivities in their response to iron supply. Future biogeochemical models will need to consider the combined and individual effects of iron and light to better resolve the natural background in primary production and predict its response under a changing climate.

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