A new genus of frenulates (Annelida: Siboglinidae) from shallow waters of the Yenisey River estuary, Kara Sea

2021 ◽  
Author(s):  
N. P. Karaseva ◽  
N. N. Rimskaya-Korsakova ◽  
I. A. Ekimova ◽  
M. M. Gantsevich ◽  
V. N. Kokarev ◽  
...  

Only seven frenulate species are currently known along the Eurasian coast of the Arctic Ocean. We describe a new genus and a new species of frenulates Crispabrachia yenisey, gen. nov. et sp. nov. The morphological analysis involved standard anatomical techniques, semithin sections and scanning electron microscopy (SEM). The molecular study included four markers (partial COI, 16S, 18S and 28S) and implemented Bayesian and Maximum likelihood phylogenetic approaches. The description of Crispabrachia gen. nov. is the first documented finding of frenulates in the Kara Sea at the estuary of the Yenisey River in rather shallow water (28 m). The establishment of a new genus is warranted based on the composition of morphological characters and several specific features including free, comparatively short curly tentacles, a triangular cephalic lobe with amplate base, the valvate extension of the posterior part of the forepart and prominent papillae on the nonmetameric region. The tube structure with prominent frills and the worm’s numerous tentacles, metameric papillae with cuticular plaques and segmental furrow on the forepart indicate that the new genus belongs to the polybrachiid group. Although the type locality in the Yenisey River estuary is unusual for siboglinids in general, the physical conditions here are common for other frenulates habitats, i.e. salinity ~30–33, bottom water temperature –1.5°C. This finding was made in the Yenisey Gulf in the region with the highest methane concentrations in the southern part of the Kara Sea that reflects permafrost degradation under the influence of river flow. Further study of the region would help to understand the factors influencing frenulate distributions and improve our knowledge of their biodiversity.

2020 ◽  
Vol 29 (1) ◽  
pp. 138-154
Author(s):  
R.V. Smirnov ◽  
O.V. Zaitseva ◽  
A.A. Vedenin

A new species of Pogonophora obtained from one station at a depth of 25 m from near the Dikson Island in the Kara Sea is described. Galathealinum karaense sp. nov. is one of the largest pogonophorans, the first known representative of the rare genus Galathealinum Kirkegaard, 1956 in the Eurasian part of the Arctic Ocean and a highly unusual finding for the desalted shallow of the Yenisey Gulf. Several characters occurring in the new species are rare or unique among the congeners: under-developed, hardly discernible frills on the tube segments, extremely thin felted fibres in the external layer of the tube, and very faintly separated papillae in the anterior part of the trunk. Morphological characters useful in distinguishing species within the genus Galathealinum are defined and summarised in a table. Diagnosis of the genus Galathealinum is emended and supplemented by new characters. Additionally, three taxonomic keys are provided to the species of Galathealinum and to the known species of the Arctic pogonophorans using either animals or their empty tubes only, with the brief zoogeographical information on each Arctic species.


Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 434 ◽  
Author(s):  
Irina Streletskaya ◽  
Alexander Vasiliev ◽  
Gleb Oblogov ◽  
Dmitry Streletskiy

Permafrost degradation of coastal and marine sediments of the Arctic Seas can result in large amounts of methane emitted to the atmosphere. The quantitative assessment of such emissions requires data on variability of methane content in various types of permafrost strata. To evaluate the methane concentrations in sediments and ground ice of the Kara Sea coast, samples were collected at a series of coastal exposures. Methane concentrations were determined for more than 400 samples taken from frozen sediments, ground ice and active layer. In frozen sediments, methane concentrations were lowest in sands and highest in marine clays. In ground ice, the highest concentrations above 500 ppmV and higher were found in massive tabular ground ice, with much lower methane concentrations in ground ice wedges. The mean isotopic composition of methane is −68.6‰ in permafrost and −63.6‰ in the active layer indicative of microbial genesis. The isotopic compositions of the active layer is enriched relative to permafrost due to microbial oxidation and become more depleted with depth. Ice-rich sediments of Kara Sea coasts, especially those with massive tabular ground ice, hold large amounts of methane making them potential sources of methane emissions under projected warming temperatures and increasing rates of coastal erosion.


Zootaxa ◽  
2020 ◽  
Vol 4808 (1) ◽  
pp. 79-100 ◽  
Author(s):  
ELENA M. KRYLOVA ◽  
HEIKO SAHLING

A new monotypic genus, Turneroconcha, is established for T. magnifica (Boss & Turner) which was originally assigned to the genus Calyptogena Dall. The distinguishing morphological characters of the new genus are the combination of both conchological and anatomical features including: the presence of only two tooth elements in the right valve; submerged location of the posterior part of the posterior lamellar ligament layer; the absence of a subumbonal pit, lunular incision, escutcheon and pallial sinus; the presence of both pairs of demibranchs; the tubular structure of marginal parts of the interlamellar septa in gills; an inner valve of the inhalant siphon without processes; tentaculate inner mantle fold 3 and a Z-shaped digestive tract. Analysis of morphological data on Recent and fossil pliocardiines shows that Turneroconcha gen. nov. can be presently considered as a monotypic genus. The comparative morphological analysis of the new genus with described pliocardiine genera is consistent with available molecular results. Turneroconcha gen. nov. is endemic to the East-Pacific Rise and Galapagos Rift and occurs at water depths of 2251 to 2791 m. It is the only pliocardiine genus known so far with a mainly epifaunal life habit. No fossils of Turneroconcha gen. nov. are known.  


2005 ◽  
Vol 19 (4) ◽  
pp. 325 ◽  
Author(s):  
Hiroshi Fukuda ◽  
Winston F. Ponder

A new genus, Cryptassiminea, is introduced for the taxon previously known as Assiminea buccinoides (Quoy & Gaimard). These small gastropods are abundant in mangrove and salt marsh habitats in south-eastern and subtropical eastern Australia. Seven species (five new) are recognised using morphological characters in the complex previously treated as a single species. Five taxa have rather narrow ranges while the other two are widespread and often sympatric. Two groups of species are recognised. One contains Cryptassiminea buccinoides, widespread in south-east and east Australia, and two closely related allopatric taxa from South Australia and south-eastern Tasmania (C. adelaidensis, sp. nov. and C. kershawi, sp. nov.). A second group of species is typified by Cryptassiminea tasmanica (Tenison-Woods), also widespread in east and south-east Australia and often sympatric with C. buccinoides. Allied to C. tasmanica, are two closely related taxa from western Victoria: C. glenelgensis, sp. nov. from the Glenelg River estuary and C. surryensis, sp. nov. from the Surry River estuary and Western Port, in the vicinity of Geelong. A distinctive species, Cryptassiminea insolata, sp. nov. from the east coast of Queensland, also has similarities with C. tasmanica. A cladistic analysis using morphological characters of the Cryptassiminea taxa and three other genera of Assimininae, with an omphalotropidine as the outgroup, resulted in a single tree. The new genus has rather poor support, possibly because many of its characters appear to be plesiomorphic within Assimineinae. Cryptassiminea is defined by a unique combination of characters but lacks any obvious synapomorphy. Two clades within Cryptassiminea are well supported, each containing the species-groups referred to above.


2014 ◽  
Vol 46 (6) ◽  
pp. 763-782 ◽  
Author(s):  
Ulrik SØCHTING ◽  
Isaac GARRIDO-BENAVENT ◽  
Rod SEPPELT ◽  
Miris CASTELLO ◽  
Sergio PÉREZ-ORTEGA ◽  
...  

AbstractBased on a combined three locus analysis two new genera,CharcotianaandAmundsenia,are proposed in the lichen familyTeloschistaceae, subfamilyXanthorioideae.Charcotianaincludes the new speciesC. antarctica, which is known only from continental Antarctica. The bipolar genusAmundseniaincludes the new speciesA. austrocontinentalis, which is also known only from continental Antarctica, and the Arctic speciesCaloplaca approximatawhich is here combined into the new genus. The two new genera are phylogenetically distinct, but poor in morphological characters; the new species consist mainly of minute apothecia in cracks of rocks located in the climatically harshest regions of the Antarctic. They are somewhat similar to another continental Antarctic species,Austroplaca frigida,which is described as a new name based on the illegitimate nameCaloplaca frigidaSøchting. The distribution of the four species is mapped.


2021 ◽  
Author(s):  
Nataliia Zadorozhnaia ◽  
Gleb Oblogov ◽  
Alexander Vasiliev ◽  
Irina Streletskaya

<p>Many researchers study the Earth's climate change and the impact of the greenhouse effect on this process. The large amount of methane (CH<sub>4</sub>) is preserved in permafrost. In this regard, scientists recently pay a great attention to the problem of methane emission during the permafrost degradation in the Arctic zone. Until now, the methane content in underground ice, frozen Quaternary sediments has been studied insufficiently. The methane content in the active layer is especially poorly studied.</p><p>The authors researched methane content in frozen grounds of the upper permafrost horizon (transition zone) and in thawed sediments of the active layer for different tundra landscapes near the Marre-Sale polar station on the western coast of the Yamal peninsula and for landscapes of the Pechora river estuary area (Russia).</p><p>More than 420 samples of gas from sediments in active and transient layer were collected in Marre-Sale and 36 samples in Pechora area. To determine the methane content, the samples were placed in syringes and degassed using the “head space” technique. CH<sub>4</sub> measurements were carried out on a chromatograph with flame ionization detector (FID) Shimadzu GC-2014 (Japan) in the laboratory of Federal State Institution “VNIIOkeangeologiya” (Saint-Petersburg, Russia).</p><p>Methane content in the frozen and thawed sediments of different dominant landscapes of typical tundra on Yamal peninsula and landscapes of southern tundra on Pechora area is extremely variable. The greatest amount of methane is typical for the most wet landscapes with primarily of silt loam soils. In dry primarily sandy well-drained landscapes, the methane content is low. The highest methane content is measured within the low floodplain of river, water tracks, swampy depressions of polygonal relief, and lake basins landscapes (mean varied from 0.8 to 2.5 ml [CH4] / kg, with a maximum of 9.0 ml [CH4] / kg). For landscapes of the moist surface of typical tundra, the average values of methane content were approximately 0.4 ml [CH4] / kg (with a maximum of 3.4 ml [CH4] / kg). The lowest methane contents in soils were characteristic of the landscapes of well-drained tundra, and sand fields where the average values do not exceed 0.2 ml [CH4] / kg. Mean methane content in soils of Pechora river mouth landscapes varied from 0.05 to 4.5 ml [CH4] / kg, with a maximum of 15.8 ml [CH4] / kg.</p><p>Determined that methane contents in the frozen soils of the transition zone is 2 to 5 times higher than in the soils of the active layer. High content of methane in upper layers of permafrost should be considered as a significant source of methane, which can be involved in emission of greenhouse gases into the atmosphere during permafrost degradation.</p>


Author(s):  
Nataliya Belova ◽  
Nataliya Belova ◽  
Alisa Baranskaya ◽  
Alisa Baranskaya ◽  
Osip Kokin ◽  
...  

The coasts of Baydaratskaya Bay are composed by loose frozen sediments. At Yamal Peninsula accumulative coasts are predominant at the site where pipeline crosses the coast, while thermoabrasional coast are prevail at the Ural coast crossing site. Coastal dynamics monitoring on both sites is conducted using field and remote methods starting from the end of 1980s. As a result of construction in the coastal zone the relief morphology was disturbed, both lithodynamics and thermal regime of the permafrost within the areas of several km around the sites where gas pipeline crosses coastline was changed. At Yamal coast massive removal of deposits from the beach and tideflat took place. The morphology of barrier beach, which previously was a natural wave energy dissipater, was disturbed. This promoted inland penetration of storm surges and permafrost degradation under the barrier beach. At Ural coast the topsoil was disrupted by construction trucks, which affected thermal regime of the upper part of permafrost and lead to active layer deepening. Thermoerosion and thermoabrasion processes have activated on coasts, especially at areas with icy sediments, ice wedges and massive ice beds. Construction of cofferdams resulted in overlapping of sediments transit on both coasts and caused sediment deficit on nearby nearshore zone areas. The result of technogenic disturbances was widespread coastal erosion activation, which catastrophic scale is facilitated by climate warming in the Arctic.


Author(s):  
Alla Savenko ◽  
Alla Savenko ◽  
Oleg Pokrovsky ◽  
Oleg Pokrovsky ◽  
Irina Streletskaya ◽  
...  

The distribution of dissolved chemical elements (major ions, nutrients, and trace elements) in the Yenisei River estuary and adjacent water area in 2009 and 2010 are presented. These results were compared to the data obtained during previous hydrochemical studies of this region. The transport of major cations (Na, K, Mg, Ca) and some trace elements (Rb, Cs, Sr, B, F, As, Mo, U) in the estuary follows conservative mixing. Alkalinity also belongs to conservative components, however this parameter exhibits substantial spatial heterogeneity caused by complex hydrological structure of the Yenisei Bay and adjoining part of the Kara Sea formed under the influence of several sources of desalination and salty waters inflow. Concentrations of Pmin, Si, and V in the desalinized waters of photic layer decrease seaward owing to uptake by phytoplankton. The losses of these elements reach 30–57, 30, and 9% of their supply by river runoff, respectively. The content of dissolved phosphates and vanadium in the intermediate and near-bottom layers of the Yenisei River estuary strongly increases with salinity due to regeneration of precipitated organic matter, whereas silica remineralization is much less pronounced. Barium is characterized by additional input of dissolved forms in the mixing zone in the quantity comparable to that carried out by river runoff. This may be caused by its desorption from river suspended matter due to ion exchange. The transport of dissolved Al and Mn in the estuarine zone is probably controlled by the coagulation and flocculation of organic and organomineral colloids, which is indicated by a decrease in the concentration of these elements at the beginning of the estuary (31 and 56%, respectively) followed by a stable concentration further seaward.


1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 648
Author(s):  
Stanislav Myslenkov ◽  
Vladimir Platonov ◽  
Alexander Kislov ◽  
Ksenia Silvestrova ◽  
Igor Medvedev

The recurrence of extreme wind waves in the Kara Sea strongly influences the Arctic climate change. The period 2000–2010 is characterized by significant climate warming, a reduction of the sea ice in the Arctic. The main motivation of this research to assess the impact of climate change on storm activity over the past 39 years in the Kara Sea. The paper presents the analysis of wave climate and storm activity in the Kara Sea based on the results of numerical modeling. A wave model WAVEWATCH III is used to reconstruct wind wave fields for the period from 1979 to 2017. The maximum significant wave height (SWH) for the whole period amounts to 9.9 m. The average long-term SWH for the ice-free period does not exceed 1.3 m. A significant linear trend shows an increase in the storm wave frequency for the period from 1979 to 2017. It is shown that trends in the storm activity of the Kara Sea are primarily regulated by the ice. Analysis of the extreme storm events showed that the Pareto distribution is in the best agreement with the data. However, the extreme events with an SWH more than 6‒7 m deviate from the Pareto distribution.


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