scholarly journals Seabed images from Southern Ocean shelf regions off the northern Antarctic Peninsula and in the southeastern Weddell Sea

2017 ◽  
Author(s):  
Dieter Piepenburg ◽  
Alexander Buschmann ◽  
Amelie Driemel ◽  
Hannes Grobe ◽  
Julian Gutt ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Scientific Information ◽  
Weddell Sea ◽  
Observation System ◽  
Marine Research ◽  
Atlantic Sector ◽  
Antarctic Marine ◽  
The Antarctic ◽  
Water Depths

Abstract. Recent advances in underwater imaging technology allow for gathering invaluable scientific information on sea- floor ecosystems, such as direct in-situ views of seabed habitats and quantitative data on composition, diversity, abundance and distribution of epibenthic fauna. The imaging approach has been extensively used within the research project Dynamics of Antarctic Marine Shelf Ecosystems (DynAMo) of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI), which aimed to comparatively assess the pace and quality of the dynamics of Southern Ocean benthos. Within this framework, epibenthic spatial distribution patterns have been comparatively investigated in two regions of the Atlantic sector of the Southern Ocean, the shelf areas off the northern tip of the Antarctic Peninsula, representing a region with above-average warming of surface waters and sea-ice reduction, and the shelves of the eastern Weddell Sea, as an example of a stable high-Antarctic marine environment that is not (yet) affected by climate change. The Ocean Floor Observation System (OFOS) of the AWI was used to collect seabed imagery during two cruises of the German research vessel Polarstern, ANT-XXIX/3 (PS81) to the Antarctic Peninsula in January–March 2013 and ANT-XXXI/2 (PS96) to the Weddell Sea from December 2015 to February 2016. Here, we report on the image and data collections gathered during these cruises. During PS81, OFOS was successfully deployed at a total of 31 stations at water depths between 29 and 784 m. At most stations, series of 500 to 530 pictures (> 15,000 in total, each depicting a seabed area of approx. 3.45 m2 (= 2.3 m × 1.5 m)) were taken along transects of approx. 3.7 km length. During PS96, OFOS was used at a total of 13 stations at water depths between 200 and 754 m, yielding series of 110 to 293 photos (2,670 in total) along transects of 0.9 to 2.6 km length. All seabed images taken during the two cruises, including metadata, are available from the data publisher PANGAEA via the two persistent identifiers doi:10.1594/PANGAEA.872719 (for PS81) and doi:10.1594/PANGAEA.862097 (for PS96).

scholarly journals Seabed images from Southern Ocean shelf regions off the northern Antarctic Peninsula and in the southeastern Weddell Sea

2017 ◽  
Vol 9 (2) ◽  
pp. 461-469 ◽  
Author(s):  
Dieter Piepenburg ◽  
Alexander Buschmann ◽  
Amelie Driemel ◽  
Hannes Grobe ◽  
Julian Gutt ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Antarctic Peninsula ◽  
Scientific Information ◽  
Weddell Sea ◽  
Observation System ◽  
Marine Research ◽  
Atlantic Sector ◽  
Antarctic Marine ◽  
The Antarctic ◽  
Water Depths

Abstract. Recent advances in underwater imaging technology allow for the gathering of invaluable scientific information on seafloor ecosystems, such as direct in situ views of seabed habitats and quantitative data on the composition, diversity, abundance, and distribution of epibenthic fauna. The imaging approach has been extensively used within the research project DynAMo (Dynamics of Antarctic Marine Shelf Ecosystems) at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research Bremerhaven (AWI), which aimed to comparatively assess the pace and quality of the dynamics of Southern Ocean benthos. Within this framework, epibenthic spatial distribution patterns have been comparatively investigated in two regions in the Atlantic sector of the Southern Ocean: the shelf areas off the northern tip of the Antarctic Peninsula, representing a region with above-average warming of surface waters and sea-ice reduction, and the shelves of the eastern Weddell Sea as an example of a stable high-Antarctic marine environment that is not (yet) affected by climate change. The AWI Ocean Floor Observation System (OFOS) was used to collect seabed imagery during two cruises of the German research vessel Polarstern, ANT-XXIX/3 (PS81) to the Antarctic Peninsula from January to March 2013 and ANT-XXXI/2 (PS96) to the Weddell Sea from December 2015 to February 2016. Here, we report on the image and data collections gathered during these cruises. During PS81, OFOS was successfully deployed at a total of 31 stations at water depths between 29 and 784 m. At most stations, series of 500 to 530 pictures ( >  15 000 in total, each depicting a seabed area of approximately 3.45 m2 or 2.3  ×  1.5 m) were taken along transects approximately 3.7 km in length. During PS96, OFOS was used at a total of 13 stations at water depths between 200 and 754 m, yielding series of 110 to 293 photos (2670 in total) along transects 0.9 to 2.6 km in length. All seabed images taken during the two cruises, including metadata, are available from the data publisher PANGAEA via the two persistent identifiers at https://doi.org/10.1594/PANGAEA.872719 (for PS81) and https://doi.org/10.1594/PANGAEA.862097 (for PS96).

How many macrozoobenthic species might inhabit the Antarctic shelf?

2004 ◽  
Vol 16 (1) ◽  
pp. 11-16 ◽  
Author(s):  
JULIAN GUTT ◽  
BORIS I. SIRENKO ◽  
IGOR S. SMIRNOV ◽  
WOLF E. ARNTZ
Keyword(s):  
Species Richness ◽  
Southern Ocean ◽  
Weddell Sea ◽  
Intermediate Species ◽  
Atlantic Sector ◽  
Species Accumulation ◽  
Antarctic Shelf ◽  
The Antarctic

Based on data from the Weddell Sea in the Atlantic sector of the Southern Ocean, the total number of macrozoobenthic species was estimated for the entire Antarctic shelf using species-accumulation methods, jack-knife estimators, and Incidence-based Coverage Estimators of species richness. Ranging between 11 000 and 17 000 expected species, Antarctica seems to have an intermediate species richness when compared to other selected tropical, temperate or Arctic habitats.

scholarly journals New species and occurrences of <i>Bradleya</i> Benson, 1972, <i>Harleya</i> Jellinek & Swanson, 2003 and <i>Poseidonamicus</i> Benson, 1972 (Ostracoda: Cytheroidea) from the Atlantic Sector of the Southern Ocean

2011 ◽  
Vol 30 (2) ◽  
pp. 141-166 ◽  
Author(s):  
Simone N. Brandão ◽  
Olinga Päplow
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Geographical Distribution ◽  
Weddell Sea ◽  
Bathymetric Distribution ◽  
Atlantic Sector ◽  
Three New Species ◽  
Abyssal Zone ◽  
The Antarctic ◽  
First Time

Abstract. The Southern Ocean shelf ostracod fauna is quite well known, while the bathyal and abyssal ones remain poorly understood. Herein, Recent Thaerocytheridae ostracods collected from deep regions in the Atlantic Sector of the Southern Ocean are described and figured. The discovery of Bradleya mesembrina Mazzini, 2005 extends its geographical and bathymetric distribution to the Antarctic zone of the Southern Ocean and to shallower (231 m) and to deeper regions (4420 m). Harleya ansoni (Whatley, Moguilevsky, Ramos &amp; Coxill, 1998) is reported for the first time from the Weddell Sea. We also describe three new species: Poseidonamicus hunti Brandão &amp; Päplow sp. nov., Poseidonamicus tainae Brandão sp. nov. and Poseidonamicus yasuharai Brandão &amp; Päplow sp. nov. For the first time we provide SEM photos of the lectotype of Poseidonamicus viminea (Brady, 1880) nomen dubium. We observe that P. yasuharai displays features intermediate to Harleya and Poseidonamicus, indicating that these two genera may require new diagnoses. The bathymetric distribution of Poseidonamicus is extended to the abyssal zone and to shallower environments, and its geographical distribution is extended southwards. Finally, the inter-specific variability in the number and type of setae and claws found on several segments of Poseidonamicus limbs are intermediate between the highly variable Bairdioidea and the homogeneous Macrocyprididae.

scholarly journals Ventilation of the abyss in the Atlantic sector of the Southern Ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camille Hayatte Akhoudas ◽  
Jean-Baptiste Sallée ◽  
F. Alexander Haumann ◽  
Michael P. Meredith ◽  
Alberto Naveira Garabato ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Bottom Water ◽  
Climate Models ◽  
Deep Ocean ◽  
Analytical Framework ◽  
Weddell Sea ◽  
Global Ocean ◽  
Shelf Water ◽  
Antarctic Bottom Water ◽  
Atlantic Sector

AbstractThe Atlantic sector of the Southern Ocean is the world’s main production site of Antarctic Bottom Water, a water-mass that is ventilated at the ocean surface before sinking and entraining older water-masses—ultimately replenishing the abyssal global ocean. In recent decades, numerous attempts at estimating the rates of ventilation and overturning of Antarctic Bottom Water in this region have led to a strikingly broad range of results, with water transport-based calculations (8.4–9.7 Sv) yielding larger rates than tracer-based estimates (3.7–4.9 Sv). Here, we reconcile these conflicting views by integrating transport- and tracer-based estimates within a common analytical framework, in which bottom water formation processes are explicitly quantified. We show that the layer of Antarctic Bottom Water denser than 28.36 kg m$$^{-3}$$ - 3 $$\gamma _{n}$$ γ n is exported northward at a rate of 8.4 ± 0.7 Sv, composed of 4.5 ± 0.3 Sv of well-ventilated Dense Shelf Water, and 3.9 ± 0.5 Sv of old Circumpolar Deep Water entrained into cascading plumes. The majority, but not all, of the Dense Shelf Water (3.4 ± 0.6 Sv) is generated on the continental shelves of the Weddell Sea. Only 55% of AABW exported from the region is well ventilated and thus draws down heat and carbon into the deep ocean. Our findings unify traditionally contrasting views of Antarctic Bottom Water production in the Atlantic sector, and define a baseline, process-discerning target for its realistic representation in climate models.

Movements of southern elephant seals

1996 ◽  
Vol 74 (8) ◽  
pp. 1485-1496 ◽  
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.

Molecular systematics of Thouarella (Octocorallia:Primnoidae) with the description of three new species from the Southern Ocean based on combined molecular and morphological evidence

2021 ◽  
Author(s):  
Mónica Núñez-Flores ◽  
Daniel Gomez-Uchida ◽  
Pablo J. López-González
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Species Delimitation ◽  
Nuclear Dna ◽  
Phylogenetic Analyses ◽  
Weddell Sea ◽  
Morphological Evidence ◽  
Three New Species ◽  
Taxonomic Framework ◽  
The Antarctic

Thouarella Gray, 1870, is one of the most speciose genera among gorgonians of the family Primnoidae (Cnidaria:Octocorallia:Anthozoa), being remarkably diverse in the Antarctic and sub-Antarctic seafloor. However, their diversity in the Southern Ocean is likely underestimated. Phylogenetic analyses of mitochondrial and nuclear DNA markers were integrated with species delimitation approaches as well as morphological colonial and polyps features and skeletal SEM examinations to describe and illustrate three new species within Thouarella, from the Weddell Sea, Southern Ocean: T. amundseni sp. nov., T. dolichoespinosa sp. nov. and T. pseudoislai sp. nov. Our species delimitation results suggest, for the first time, the potential presence of Antarctic and sub-Antarctic cryptic species of primnoids, based on the likely presence of sibling species within T. undulata and T. crenelata. With the three new species here described, the global diversity of Thouarella has increased to 41 species, 15 of which are endemic to the Antarctic and sub-Antarctic waters. Consequently, our results provide new steps for uncovering the shelf benthonic macrofauna’s hidden diversity in the Southern Ocean. Finally, we recommend using an integrative taxonomic framework in this group of organisms and species delimitation approaches because the distinctions between some Thouarella species based only on a superficial examination of their macro- and micromorphological features is, in many cases, limited.

scholarly journals A description and summary of the Antarctic Humpback Whale Catalogue

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.

The role of fish in the Antarctic marine food web: differences between inshore and offshore waters in the southern Scotia Arc and west Antarctic Peninsula

2002 ◽  
Vol 14 (4) ◽  
pp. 293-309 ◽  
Author(s):  
ESTEBAN BARRERA-ORO
Keyword(s):  
Food Web ◽  
Antarctic Peninsula ◽  
Demersal Fish ◽  
Pelagic Fish ◽  
West Antarctic ◽  
Antarctic Marine ◽  
Scotia Arc ◽  
West Antarctic Peninsula ◽  
The Antarctic

The role of fish in the Antarctic food web in inshore and offshore waters is analysed, taking as an example the coastal marine communities of the southern Scotia Arc (South Orkney Islands and South Shetland Islands) and the west Antarctic Peninsula. Inshore, the ecological role of demersal fish is more important than that of krill. There, demersal fish are major consumers of benthos and also feed on zooplankton (mainly krill in summer). They are links between lower and upper levels of the food web and are common prey of other fish, birds and seals. Offshore, demersal fish depend less on benthos and feed more on zooplankton (mainly krill) and nekton, and are less accessible as prey of birds and seals. There, pelagic fish (especially lantern fish) are more abundant than inshore and play an important role in the energy flow from macrozooplankton to higher trophic levels (seabirds and seals). Through the higher fish predators, energy is transferred to land in the form of fish remains, pellets (birds), regurgitation and faeces (birds and seals). However, in the general context of the Antarctic marine ecosystem, krill (Euphausia superba) plays the central role in the food web because it is the main food source in terms of biomass for most of the high level predators from demersal fish up to whales. This has no obvious equivalent in other marine ecosystems. In Antarctic offshore coastal and oceanic waters the greatest proportion of energy from the ecosystem is transferred to land directly through krill consumers, such as flying birds, penguins, and seals. Beside krill, the populations of fish in the Antarctic Ocean are the second most important element for higher predators, in particular the energy-rich pelagic Myctophidae in open waters and the pelagic Antarctic silver fish (Pleuragramma antarcticum) in the high Antarctic zone. Although the occurrence of these pelagic fish inshore has been poorly documented, their abundance in neritic waters could be higher than previously believed.

Description of three new species of the deep-sea munnopsid genus Belonectes (Crustacea, Isopoda, Asellota) from the Weddell Sea, Southern Ocean

Zootaxa ◽  
2009 ◽  
Vol 2277 (1) ◽  
pp. 33-52
Author(s):  
MARINA V. MALYUTINA ◽  
ANGELIKA BRANDT
Keyword(s):  
New Species ◽  
Southern Ocean ◽  
Weddell Sea ◽  
Distal Margin ◽  
Atlantic Sector ◽  
Medial Lobe ◽  
Southeastern Pacific ◽  
Three New Species ◽  
Article 5 ◽  
Northeastern Atlantic

Three new species of the genus Belonectes Wilson & Hessler, 1981, from the munnopsid subfamily Eurycopinae Hansen are described from the deep Weddell Sea, Atlantic sector of the Southern Ocean. Belonectes grasslei sp. nov., B. stoddarti sp. nov., and B. daytoni sp. nov. are the first species of the genus described from the region: previously only two species of Belonectes were known from the northeastern Atlantic and the Peru-Chile Trench, the southeastern Pacific. The modified diagnosis of the genus Belonectes and a key to the species of the genus are presented. The pattern of the total ventral sculpture of the natasome, a medial lobe of article 4 of the maxillipedal palp which is larger than article 5 and the navicular male pleopod 1 with its deep keel are suggested to be additional important generic characters of Belonectes. The most useful characters to distinguish species of Belonectes are the size of article 1 of the antennula, the shape and size of the articles 3–5 of the maxillipedal palp, the shape of the distal margin of the male pleopod 1, the shape of distolateral part of the protopod of the male pleopod 2, the size and shape of the preanal ridge, and the size of the exopod of the uropod.

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