scholarly journals CO1 Metabarcoding of Marine Water Samples from the 2nd Turkish Antarctic Expedition (TAE2) Highlights the Deficiencies in the Reference Barcoding Databases for the Continent

2021 ◽  
Vol 4 ◽  
Author(s):  
Rasit Bilgin ◽  
Kübra Karaman ◽  
Yağmur Tarhana ◽  
Ceylan Yücel ◽  
Elizabeth Hemond ◽  
...  

Based on climate projections, the Antarctic Peninsula is one of the regions on the earth expected to be most drastically affected by climate change in the 2nd half of the 21st century. In order to establish baseline levels of marine biodiversity using the environmental DNA approach, we undertook metabarcoding based on the CO1 gene. Samples were collected using 0.22 mM pore-sized Sterivex filters during TAE2 undertaken in 2018, from one site at Deception Island (2 filters), one site at Nansen Island (2 filters), and three sites (one offshore) at Robert Island. A total of 20 taxa were identified (unique hits with BLAST percent identity ≥ 97%) belonging to three kingdoms (Chromista, Plantae, Animalia), nine phyla, 11 classes, 17 orders, 19 families, and 20 genera. Of these, 18 were identified to the species level, one to the genus level, and the other one to the family level. Genetically identified taxa included seven planktonic algae, nine seaweeds, a stalked jellyfish, a nematode, a planktonic copepod, and a demersal fish. In addition, 129 unique OTUs were detected (unique hits with BLAST percent identity < 97%) as unidentified. These results indicate the high levels of undocumented genetic diversity (without CO1 barcode sequences in GenBank) in the Antarctic Peninsula region and adjacent waters, and the need for more work to complete the reference barcode databases for the continent. A dendrogram resulting from cluster analysis (Bray-Curtis similarity measure, group-average linkage) based on the presence/absence data of 20 identified species revealed three well-defined sample (i.e. filter containing DNA fragments of multiple taxa) groups, which almost coincided with their geographical locations. First group included samples (filters) collected from the coast of Deception Island and the second one from the coast of Robert Island, both in the South Shetland Islands, off the northern tip of the Antarctic Peninsula. The third group included samples from Nansen Island coast (off the west coast of Graham Land, Antarctic Peninsula) together with the only sample collected offshore, off Robert Island. The significance of this clustering, thus the difference among sampling sites with regard to species composition, was confirmed by Analysis of Similarity (ANOSIM) results (Global R = 0.982, p = 0.001). The highest number of identified taxa (per filter) and unidentified OTUs (per filter) were observed offshore off Robert Island. Considering that all of the other sampling sites were by the coasts of islands, this observation indicates i) the offshore waters might contain more DNA-bearing material than coastal sites, and/or ii) a methodological issue where the high phytoplankton and suspended matter concentrations by the coasts created a bottleneck in terms of capturing actual species diversity at the coasts, due to clogging of filters by phytoplankton and fine suspended particles.

2014 ◽  
Vol 27 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Facundo Llompart ◽  
Matías Delpiani ◽  
Eugenia Lattuca ◽  
Gabriela Delpiani ◽  
Adriana Cruz-Jiménez ◽  
...  

AbstractDuring the research programme conducted on the OV Puerto Deseado in the summers of 2011 and 2013, 36 stations were sampled using a demersal net at depths between 53–590 m in the Antarctic Peninsula and South Shetland Islands. A total 3378 fish specimens belonging to 36 species were recorded. Notothenidae was the best-represented family in species number, with Lepidonotothen nudifrons, L. larseni and Trematomus scotti being the most numerous species. Of the fish assemblages, 20% of the species were considered as dominant, 10% as common, 13% as occasional and 57% as rare. Six groups (and two sub-groups) were obtained by the ordination diagram based on geographical location: group 1=Gerlache Strait, group 2=Deception Islands, group 3=Biscoe Island, group 4=between Elephant and King George islands, group 5=northern Antarctic Peninsula, and group 6=South Shetland Islands, with sub-groups 6a shallower South Shetland Islands and 6b deeper South Shetland Islands. Sampling depth and water temperature significantly explained the spatial pattern. A latitudinal pattern of decreasing abundance from north-east to south-west was found in L. larseni and the opposite in T. scotti. The predictability of fish composition in the assemblages’ areas could be a useful tool for ecosystem-based management.


2011 ◽  
Vol 32 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Vagn Alstrup ◽  
Ulrik Søchting

Massalongia olechiana (Massalongiaceae, Peltigerales), a new lichen species from the Antarctic A new species of lichenized ascomycete, Massalongia olechiana Alstrup et Søchting, sp. nov. (Massalongiaceae) is described from the South Shetland Islands and the Antarctic Peninsula. The species is distinguished by laminal isidia and 5-7-septate ascospores. The relationships with the other species of the genus are discussed. From Massalongia carnosa, recorded from both the Arctic and the Antarctic, the new species is distinguished by its lack of isidioid squamules and in having pluriseptate ascospores instead of 1-septate ascospores.


1997 ◽  
Vol 9 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Masanori Takahashi ◽  
Tetsuo Iwami

The stomach contents of demersal fish in late January 1982 were analysed. Samples were taken at 100, 300 and 500 m depth south of Elephant Island, Bransfield Strait and north of Livingston Island, and at 800 m to the east of Smith Island. Fifty four taxa of fish belonging to 11 families were collected. The diets of 2101 fish representing 38 taxa were examined. These were classified into three categories, fish feeders, krill feeders and benthos feeders. Fish prey species fed on krill and/or benthos. Krill was a major dietary component for 32 (84.2%) out of 38 taxa. Gobionotothen gibberifrons was distributed at all 10 stations (100–800 m in depth) and its diet comprised krill and benthos. The present findings verify the importance of krill in the Antarctic marine ecosystem and indicate that krill is consumed by benthic fish at greater depths than previously reported.


Polar Record ◽  
2009 ◽  
Vol 46 (3) ◽  
pp. 210-221 ◽  
Author(s):  
J. Stephen Dibbern

ABSTRACTDeception Island in the South Shetland Islands was the site of some of the earliest commercial activity to be carried out in the Antarctic with the early 19th century hunting of Antarctic fur seals. Nearly a century later it was the site of the most extensive anchorage for the reconstructed ships and ocean liners used as non-pelagic whale processing factories. Deception was also the site of what is the only successful land based commercial activity in Antarctic history. The Hektor whaling station operated in Whalers Bay from 1912 until 1931. Most of the remains of the station have now been obliterated by the volcanic activity that occurred in the late 1960s and 1970. By the later part of the twentieth century Deception Island had become a regular stop for the growing Antarctic tourist cruise industry. No other place in Antarctica has been so thoroughly identified with commercial activity.


2002 ◽  
Vol 14 (4) ◽  
pp. 293-309 ◽  
Author(s):  
ESTEBAN BARRERA-ORO

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.


2021 ◽  
pp. M55-2018-68 ◽  
Author(s):  
Philip T. Leat ◽  
Teal R. Riley

AbstractThe Antarctic Peninsula contains a record of continental-margin volcanism extending from Jurassic to Recent times. Subduction of the Pacific oceanic lithosphere beneath the continental margin developed after Late Jurassic volcanism in Alexander Island that was related to extension of the continental margin. Mesozoic ocean-floor basalts emplaced within the Alexander Island accretionary complex have compositions derived from Pacific mantle. The Antarctic Peninsula volcanic arc was active from about Early Cretaceous times until the Early Miocene. It was affected by hydrothermal alteration, and by regional and contact metamorphism generally of zeolite to prehnite–pumpellyite facies. Distinct geochemical groups recognized within the volcanic rocks suggest varied magma generation processes related to changes in subduction dynamics. The four groups are: calc-alkaline, high-Mg andesitic, adakitic and high-Zr, the last two being described in this arc for the first time. The dominant calc-alkaline group ranges from primitive mafic magmas to rhyolite, and from low- to high-K in composition, and was generated from a mantle wedge with variable depletion. The high-Mg and adakitic rocks indicate periods of melting of the subducting slab and variable equilibration of the melts with mantle. The high-Zr group is interpreted as peralkaline and may have been related to extension of the arc.


1995 ◽  
Vol 69 (1) ◽  
pp. 66-84 ◽  
Author(s):  
Simon R. A. Kelly

New discoveries of trigonioid bivalves are documented from three areas in the Antartic Peninsula: the Fossil Bluff Group of Alexander Island, the Latady Formation of the Orville Coast, and the Byers Group of Livingston Island, South Shetland Islands. Eleven taxa are described, representing six genera or subgenera. The faunas are characterized by genera including Vaugonia (Vaugonia), the first Early Jurassic trigonioid recognized on the continent; Vaugonia (V.) and V. (Orthotrigonia?) in the Late Jurassic; and Iotrigonia (Iotrigonia), Myophorella (Scaphogonia), and Pterotrigonia (Pterotrigonia), which span the Jurassic–Cretaceous boundary, reaching the Berriasian stage. The following species are new: Pterotrigonia (P.) cramei n. sp., Pterotrigonia (P.) thomsoni n. sp., Vaugonia (V.) orvillensis n. sp., and V. (Orthotrigonia?) quiltyi n. sp. The faunas show affinities with those of New Zealand and southern Africa. Trigonioids characterize the shallower marine biofacies in the Jurassic of the Antarctic and reflect the principal shallowing events in the history of the region.


2004 ◽  
Vol 16 (3) ◽  
pp. 339-344 ◽  
Author(s):  
BRENDA L. HALL ◽  
ETHAN R. PERRY

Raised beach ridges on Livingston Island of the South Shetland Islands display variations in both quantity and source of ice rafted detritus (IRD) received over time. Whereas the modern beach exhibits little IRD, all of which is of local origin, the next highest beach (∼250 14C yr BP) has large amounts, some of which comes from as far away as the Antarctic Peninsula. Significant quantities of IRD also were deposited ∼1750 14C yr BP. Both time periods coincide with generally cooler regional conditions and, at least in the case of the ∼250 yr old beach, local glacial advance. We suggest that the increases in ice rafting may reflect periods of greater glacial activity, altered ocean circulation, and/or greater iceberg preservation during the late Holocene. Limited IRD and lack of far-travelled erratics on the modern beach are both consistent with the ongoing warming trend in the Antarctic Peninsula region.


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