Geologic history of the Maurice Ewing Bank of the Falkland Plateau (southwest Atlantic sector of the Southern Ocean) based on piston and drill cores

1977 ◽  
Vol 25 (1-3) ◽  
pp. 175-207 ◽  
Author(s):  
Paul F. Ciesielski ◽  
Sherwood W. Wise
1995 ◽  
Vol 7 (3) ◽  
pp. 221-226 ◽  
Author(s):  
S.A. Evseenko ◽  
K.-H. Kock ◽  
M.M. Nevinsky

Dissostichus eleginoides spawn over the continental slope from June to September. The eggs, 4.3–4.7 mm diameter, were found in the upper 500 m of the water column over waters 2200–4400 m deep. Incubation of eggs is likely to take about three months. Hatching is probably in October/November. Embryos in egg development stages III and IV are described. Scales are not present until the fish are about 64–74 mm long.


2021 ◽  
Author(s):  
Banafsheh Najjarifarizhendi ◽  
Gabriele Uenzelmann-Neben

<p>High-resolution 2D multichannel seismic data collected by the Alfred Wegener Institute in 2019 across the Maurice Ewing Bank, the high-altitude easternmost section of the Falkland Plateau in the SW South Atlantic, are integrated with information from DSDP Leg 36, Sites 327, 329, and 330 and Leg 71 Site 511. A seismostratigraphic model is defined, including five units ranging in age from the Middle Jurassic to Quaternary and are interpreted with respect to the evolutional history of the oceanic circulations in the South Atlantic sector of the Southern Ocean. Sedimentary sequences of late Cretaceous and early Paleogene include little and restricted evidence of current activity, attributable to shallow-intermediate depth connections between the developing South Atlantic and Southern Ocean. In contrast, sedimentary sequences of the late Eocene/Oligocene and Neogene reveal a strong history of current-related erosion and deposition. These features exhibit specific water-depth expressions attesting to the long-term activity of different water masses, in stable circulation patterns as those of the present day. We thus suggest that proto-Upper and -Lower Circumpolar Deep Waters have been shaping the bank since the Oligocene. This implies that this bathymetric high has been acting as a barrier for the deep and bottom water masses flowing within the Antarctic Circumpolar Current since its establishment about the Eocene-Oligocene boundary.</p>


2020 ◽  
pp. 137-158
Author(s):  
So Kawaguchi ◽  
Stephen Nicol

Antarctic krill is a key species in the Southern Ocean ecosystem as well as the target for the largest fishery in the Southern Ocean, which has been operating continuously since the early 1970s. The krill fishery began by operating all around the continent but gradually contracted to the West Antarctica in the 1990s, where it is currently concentrated on a few fishing grounds in the Southwest Atlantic sector. This fishery has regained some commercial attraction because of recent technological developments in harvesting and processing. These developments permit the production of high-value products, and the total annual catch has increased to nearly 400,000 t over the last decade. Climate change has already affected the krill fishery, with the reduced winter sea ice in the South Atlantic allowing current fishery operations farther south than what was previously possible. The Antarctic krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Its management system is unique in taking into account the state of the ecosystem as well as that of the harvested stock. The establishment of a feedback management approach for this fishery has been the major task for the Scientific Committee of CCAMLR to realize this ecosystem-based management objective. This chapter provides a general introduction to krill biology and ecology, followed by a narrative of the forces that prompted the development of a krill fishery and the current issues that surround its management.


2018 ◽  
Author(s):  
Angelika Wanda Słomska ◽  
Anna Panasiuk ◽  
Agata Weydmann-Zwolicka ◽  
Justyna Wawrzynek-Borejko ◽  
Marta Konik ◽  
...  

AbstractOver the last three decades, a significant variability in Salpa thompsoni occurrence has been observed as a response to the environmental fluctuations of the Southern Ocean ecosystem, e.g. changes in sea surface temperature as well as shrinking of ice-cover extent around the cold Antarctic waters.This study presents the historical data of salps abundance from the southwest Atlantic Sector of the Southern Ocean and covers time span of 20 years. Presented dataset allowed to track previous fluctuations in Antarctic salp abundance and enabled to combine their distribution with different bottom depth, thermal and ice conditions. The subsequent goal of this work was to reveal hot spots of salps location and to predict the future range of S. thompsoni distribution with upcoming climate warming in the next 50 years.Results of our study revealed that the highest salp number was located mostly in the shallow shelf waters with ice-cover and lower temperature. In the studied area, Salpa thompsoni hot spot distributions have been located mostly around Elephant Island but also within islands around Brensfield and Gerlache Straits, as well as to the south near the cold Bellingshausen Sea. The inference of future salp distribution demonstrated that the range of S. thompsoni would presumably move southwards enlarging their habitat area by nearly 500 000 km2.


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