scholarly journals Salinity gradient meiobenthos distribution on the Razdolnaya River’s estuary

2018 ◽  
Vol 7 (1) ◽  
pp. 76-83
Author(s):  
Alexandra Alexandrovna Milovankina ◽  
Natalia Petrovna Fadeeva ◽  
Elena Sergeevna Chertoprud
Keyword(s):  
Salinity Gradient ◽  
Far East ◽  
Nematode Community ◽  
The Sea Of Japan ◽  
Freshwater Species ◽  
Estuarine Zone ◽  
Harpacticoid Copepods ◽  
Mesohaline Zone ◽  
Taxonomic Groups ◽  
Specific Species

The paper studies salinity gradient meiobenthos distribution based on the results of the benthic surveys of the Razdolnaya estuary (the Sea of Japan, Amursky Bay). The density was increased with salinity growth on the Razdolnaya Rivers estuary. Meiobenthos was comprised by 8 taxonomic groups (Nematoda, Copepoda, Ostracoda, Oligochaeta, Mollusca, Amphipoda, Polychaeta и Chironomidae) with the dominance of nematodes. Most of meiobenthic species are presented by marine euryhaline species and registered throughout the Razdolnaya Rivers estuary. Fresh water species Dorylaimus chassanicus, Hofmaenneria gratiosa, Theristus brevisetosus and nematodes of the genera Paradontophora , widespread on estuaries of Far East of Russia, were dominated in meiobenthos in oligohaline zone of estuary; Monhystrella sp. Oncholaimium japonicum, Anoplostoma cuticularia, Daptonema inversum and Harpacticoid Copepods Remanea naksanensis, Onychocamptus mohammed, Huntemannia biarticulatus, Halectinosoma sp. were dominated in mesohaline zone. Nematode community are changed by zones throughout the estuary: Paradontophora genera are dominated in freshwater and olihaline zones, as well as freshwater species ( Dorylaimus chassanicus, Hofmaenneria gratiosa, Theristus brevisetosus ) were presented; Monhystrella sp. are dominated and freshwater spicies are decreased in the number at the mesohaline zone; Paracanthonchus macrodon, Onсholaimium paraolium, Sabatieria finitima, Dorylaimopsis peculiaris and S. palmaris are dominated at the euhaline zone. The nematocenes of inner part of estuarine zone arent characterized by specific species assemblage and consist of species typical for nematode community of shallow water and of marine zones.

The first lichenological survey in Koryakia (Northern Kamchatka, Russia) — the last unexplored part of Beringia

2019 ◽  
Vol 53 (1) ◽  
pp. 107-142 ◽  
Author(s):  
D. E. Himelbrant ◽  
I. S. Stepanchikova ◽  
T. Ahti ◽  
V. Yu. Neshataeva
Keyword(s):  
East Asia ◽  
Russian Far East ◽  
Far East ◽  
Kamchatka Peninsula ◽  
Lichen Diversity ◽  
Magadan Region ◽  
Specific Species ◽  
First Time ◽  
Lichen Flora

The first lichenological inventory in Koryakia has resulted in the list of 315 species reported from Parapolsky Dale, within and in vicinities of the Koryak State Reserve. Altogether 46 species are published from the Kamchatka Territory for the first time, including Lecanographa grumulosa new to Russia, East Asia and Beringia; Cercidospora trypetheliza, Lecania dubitans, Pertusaria borealis, Piccolia ochrophora, Protoparmelia cupreobadia, Rimularia badioatra and Strangospora moriformis new to Russian Far East; Abrothallus bertianus, Cladonia strepsilis, Physciella melanchra, Rimularia badioatra, Sclerococcum parasiticum, Sphinctrina leucopoda and Strangospora moriformis new to Beringia. The lichen diversity of the study area is relatively poor due to natural reasons. Comparison with neighboring regions (Kamchatka Peninsula, Chukotka, Magadan Region, Yakutia and Alaska) shows that the lichen flora of Parapolsky Dale contains almost no specific species. The majority of the species recorded here are also known from neighboring regions, especially Alaska and Kamchatka Peninsula.

The large-scale vegetation maps of the western coast of Peter the Great Bay (Far East, the Sea of Japan)

2000 ◽  
pp. 50-61 ◽  
Author(s):  
S. V. Osipov ◽  
V. P. Verkholat
Keyword(s):  
Vegetation Cover ◽  
Large Scale ◽  
Far East ◽  
Peter The Great Bay ◽  
The Sea Of Japan ◽  
Western Coast ◽  
Spatial Unit ◽  
Peter The Great ◽  
Great Bay ◽  
River Valleys

Two territories on the western coast of Peter the Great Bay were mapped in the large scale. The geobotanical mapping means revealing and displaying the essential regularities of vegetation cover. Both the spatial and temporal regularities of vegetation under natural and anthropogenic influences are well pronounced in the territory under consideration. The concept of the vegetation spatial unit (vegetation complexes) was applied as a basis for mapping. The maps and their legend were worked out as a system of vegetation combination types (vegetation combination is a spatial unit of the supracoenotic level). Such categories, as vegetation of tops and slopes, lowlands and river valleys, sea coasts reflect maximal contrasts in vegetation cover, so they are the highest level divisions of the map legend. Types of succession series and stages of series are developed for construction of the second and third levels of the legend. Communities, similar in ecotope, total species composition, saplings and some other characteristics, are referred to one type of series. 5 types of series have been distinguished: dry, fresh, moist, very moist, wet. The main factor of dynamics in considered territory is fire and the series are mainly pyrogeneous. Series are presented as sequences of vegetation stages. The vegetation stages for tops and slopes are: closed low forest — open low woodland — shrub thicket with saplings — meadow with saplings, for lowlands and river valleys they are: open low woodland — thicket of saplings — meadow or mire with saplings.

scholarly journals Paleogeographical Researches in Pacific Geographical Institute

2021 ◽  
pp. 15-32
Author(s):  
Н.Г. Разжигаева ◽  
Л.А. Ганзей ◽  
Т.А. Гребенникова ◽  
В.Б. Базарова ◽  
П.С. Белянин ◽  
...  
Keyword(s):  
Climate Changes ◽  
Far East ◽  
High Temporal Resolution ◽  
The Sea Of Japan ◽  
The South ◽  
Short Term ◽  
Natural Factors ◽  
Middle Mountains ◽  
Eastern Mongolia

Представлены результаты работы лаборатории палеогеографии и геоморфологии ТИГ ДВО РАН в 2017–2020 гг. Приведены новые данные по изучению развития материковых и островных геосистем юга Дальнего Востока и реакции их компонентов на короткопериодные климатические изменения позднего плейстоцена–голоцена. Палеоэкологические изменения с высоким временным разрешением восстановлены в среднегорье Восточного Сихотэ-Алиня. Новые данные получены по развитию геосистем побережья Японского моря, определена роль зональных и азональных природных факторов в их развитии. Выделены этапы развития ландшафтов платобазальтового рода. Реконструированы обстановки осадконакопления и формирования пойменных ландшафтов Приханкайской равнины. Сделаны детальные реконструкции хода развития островных ландшафтов для юга Приморья. Для юга Дальнего Востока проведен синтез изменений ландшафтов в последнее интенсивное потепление – малый оптимум голоцена (VII–XIII вв.). Проанализировано проявление природных катастроф и их пространственно-временной масштаб. Продолжены работы, направленные на оценку цунамиопасности на побережье восточного Приморья. Для Курильских островов выделены наиболее сильные цунами, которые могут быть рассмотрены как кандидаты в мегацунами. Внимание уделено трансформации ландшафтов при освоении территории юга Дальнего Востока древним человеком. Геоархеологические исследования проводились также во внутриконтинентальных районах (Западное Забайкалье, Восточная Монголия). The authors present the results of the researches of the laboratory of paleogeography and geomorphology of PGI FEB RAS in 2017–2020. New data include the study of the development of continental and island geosystems of the South Far East and the response of their components to short-term climate changes in the Late Pleistocene-Holocene. Paleoecological changes with a high temporal resolution have been restored in the middle mountains of the Eastern Sikhote-Alin. New data were obtained on the development of geosystems of the coast of the Sea of Japan, the role of zonal and azonal natural factors in their development was determined. The stages of development of landscapes of the platobasalt genus are highlighted. The conditions of sedimentation and formation of floodplain landscapes of the Khanka Lake plain were reconstructed. Detailed reconstructions of the island landscapes development for the south of Primorye have been made. For the south of the Far East, a synthesis of landscape changes in the last intense warming – Medieval Warm Period of the Holocene (VII-XIII centuries) was made. The manifestation of natural disasters and their space-time scale were analyzed. The investigations aimed at assessment of the tsunami hazard on the coast of eastern Primorye were continued. For the Kuril Islands, the most powerful tsunamis have been identified, which can be considered as candidates for megatsunami. Transformation of landscapes and a human impact on landscapes were also discussed. Geoarchaeological studies were also carried out in the intra-continental regions (Western Transbaikalia, Eastern Mongolia).

scholarly journals Polychaetes associated with decaying wood in Térraba mangrove, South Pacific, Costa Rica

2016 ◽  
pp. 61-74
Author(s):  
Jeffrey A. Sibaja-Cordero ◽  
Silvia Echeverría-Sáenz
Keyword(s):  
Costa Rica ◽  
Salinity Gradient ◽  
Benthic Fauna ◽  
Central American ◽  
Faunal Assemblage ◽  
Sediment Samples ◽  
Estuarine Zone ◽  
Decaying Wood ◽  
Number Of Individuals ◽  
Sand Bottom

The present study shows spatial patterns in the faunal assemblage of decaying wood and sediments, with emphasis on the polychaetes. The survey was executed across a salinity gradient in a tropical mangrove estuary of Costa Rica. To capture the organisms we analyzed decomposing logs found in the Térraba mangrove and sediment samples were taken with a corer in the sand bottom. Seven different phyla were found in the sediment samples. Of the 192 individuals found in the sediment samples, 18 were polychaetes belonging to nine families and 11 species. Analyses of decaying wood resulted in 2 564 individuals distributed in five phyla. Polychaetes accounted for 429 individuals belonging to eight families and 16 species. Although, polychaetes were more abundant in decaying wood, and their diversity was lower. The abundance of polychaetes in decaying wood was negatively correlated with the number of individuals of Mollusca, Hexapoda and Crustacea. A change in the composition of polychaetes in decaying wood was found along the salinity gradient of this estuarine zone. Dissimilarities in the composition of benthic fauna in decaying wood and sediments in the Térraba mangrove showed that biodiversity was increased by the microhabitats inside the mangrove forest. Finally, several genera or species of polychaetes are new records for Costa Rica and the Central American Pacific Coast.

Black Bass Diversity: Multidisciplinary Science for Conservation

2015 ◽  
Keyword(s):  
Spatial Variation ◽  
Largemouth Bass ◽  
Salinity Gradient ◽  
Micropterus Salmoides ◽  
Metabolic Cost ◽  
Population Level ◽  
Freshwater Species ◽  
Population Demographics ◽  
Bioenergetics Modeling ◽  
Black Bass

<em>Abstract.</em>—Largemouth Bass <em>Micropterus salmoides</em> is typically thought of as a freshwater species, but populations occur in oligohaline portions of estuaries throughout the U.S. Atlantic and Gulf of Mexico coasts, often with popular fisheries. These coastal populations must deal with the physiological stresses associated with salinity variation and may be isolated from inland freshwater populations, increasing the potential for differentiation. To understand factors important to the ecology and management of these coastal populations, we quantified individual- and population-level parameters for Largemouth Bass across a natural salinity gradient in the Mobile-Tensaw River delta in southwestern Alabama during 2002–2009 (including population demographics, feeding ecology, movement, recruitment, and bioenergetics processes). Combining traditional mark–recapture and telemetry techniques with otolith microchemical analyses, we demonstrated that Largemouth Bass of all ages moved very little, even in response to increasing salinity (up to 15‰) in downstream areas. Large individuals were rare in our sampling across both fresh and brackish habitats (only 7 out of 9,530 individuals were >2.27 kg), and fish body condition increased downstream with increasing marine influence. Growth responses for fish across the estuary were more complex, varying with both fish age and salinity. Faster growth was observed in the brackish, downstream areas for fish ≤age 2, while growth of older fish was faster in freshwater upstream sites. Using bioenergetics modeling, we demonstrated that a complex combination of spatial variation in water temperature, prey energetic content, and metabolic cost of salinity was responsible for age-specific spatial variation in growth. Preliminary genetic analysis suggests that these coastal Largemouth Bass may differ genetically from inland fish. Coastal Largemouth Bass populations face a number of potential conservation concerns, and their management will require different approaches compared to their inland counterparts, including different goals and expectations, likely even requiring consideration as unique stocks.

scholarly journals A conservation palaeobiological approach to assess faunal response of threatened biota under natural and anthropogenic environmental change

2019 ◽  
Vol 16 (12) ◽  
pp. 2423-2442 ◽  
Author(s):  
Sabrina van de Velde ◽  
Elisabeth L. Jorissen ◽  
Thomas A. Neubauer ◽  
Silviu Radan ◽  
Ana Bianca Pavel ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Changes ◽  
Sea Water ◽  
Salinity Gradient ◽  
Conservation Strategies ◽  
The Black Sea ◽  
Freshwater Species ◽  
Lake System ◽  
The Past ◽  
Mollusc Species

Abstract. Palaeoecological records are required to test ecological hypotheses necessary for conservation strategies as short-term observations can insufficiently capture natural variability and identify drivers of biotic change. Here, we demonstrate the importance of an integrated conservation palaeobiology approach when making validated decisions for conservation and mitigating action. Our model system is the Razim–Sinoie lake complex (RSL) in the Danube Delta (Black Sea coast, Romania), a dynamic coastal lake system hosting unique Pontocaspian mollusc species that are now severely under threat. The Pontocaspians refer to an endemic species group that evolved in the Black Sea and Caspian Sea basins under reduced salinity settings over the past few million years. The natural, pre-industrial RSL contained a salinity gradient from fresh to mesohaline (18 ppm) until human intervention reduced the inflow of mesohaline Black Sea water into the lake system. We reconstruct the evolution of the RSL over the past 2000 years from integrated sedimentary facies and faunal analyses based on 11 age-dated sediment cores and investigate the response of mollusc species and communities to those past environmental changes. Three species associations (“marine”, “Pontocaspian” and “freshwater”) exist and their spatio-temporal shifts through the system are documented. Variable salinity gradients developed, with marine settings (and faunas) dominating in the southern part of the system and freshwater conditions (and faunas) in the northern and western parts. Pontocaspian species have mostly occurred in the centre of the RSL within the marine–freshwater salinity gradient. Today, freshwater species dominate the entire system, and only a single Pontocaspian species (Monodacna colorata) is found alive. We show that the human-induced reduced marine influence in the system has been a major driver of the decline of the endemic Pontocaspian biota. It urges improved conservation action by re-establishing a salinity gradient in the lake system to preserve these unique species.

Chenopodium luteorubrum (Chenopodiaceae/Amaranthaceae sensu APG): a remarkable new species from the Russian Far East

Phytotaxa ◽  
2018 ◽  
Vol 382 (1) ◽  
pp. 102 ◽  
Author(s):  
BOHUMIL MANDÁK ◽  
MARIA N. LOMONOSOVA ◽  
SERGEI L. MOSYAKIN
Keyword(s):  
New Species ◽  
Sea Of Japan ◽  
Russian Far East ◽  
Far East ◽  
The Sea Of Japan ◽  
Coastal Habitats ◽  
Extinct Species ◽  
A New Species ◽  
The Russian Far East

Chenopodium luteorubrum is described as a new species of Chenopodiaceae (Amaranthaceae sensu APG) from coastal habitats along the Sea of Japan in the Russian Far East. It has been demonstrated that this allohexaploid species (2n = 6x = 54) combines in its genome the subgenomes ‘A’ (closely related to or inherited from C. bryoniifolium), ‘C’ (unknown or extinct species), and ‘D’ (C. acuminatum s. l.). That subgenome combination is unique; it differs from the combination in C. album s. str. and closely related hexaploid taxa, which have ‘B’ (derived from C. ficifolium/C. suecicum), ‘C’, and ‘D’ subgenomes. Here we describe and illustrate the new species and provide information on its evolution, ecology, morphology, karyology, and distribution. The new species is compared with morphologically somewhat similar taxa C. album s. str. (hexaploid), C. suecicum (diploid), C. betaceum s. l. (C. strictum auct., tetraploid), and C. acuminatum (diploid).

scholarly journals A conservation palaeobiological approach to assess faunal response of threatened biota under natural and anthropogenic environmental change

2019 ◽  
Author(s):  
Sabrina van de Velde ◽  
Elisabeth L. Jorissen ◽  
Thomas A. Neubauer ◽  
Silviu Radan ◽  
Ana Bianca Pavel ◽  
...  
Keyword(s):  
Black Sea ◽  
Environmental Changes ◽  
Sea Water ◽  
Salinity Gradient ◽  
Conservation Strategies ◽  
The Black Sea ◽  
Freshwater Species ◽  
Lake System ◽  
The Past ◽  
Mollusc Species

Abstract. Palaeoecological records are required to test ecological hypotheses necessary for conservation strategies as short-term observations can be insufficiently to capture natural variability and identify drivers of biotic change. Here, we demonstrate the importance of an integrated conservation palaeobiology approach to make validated decisions for conservation and mitigating action. Our model system is the Razim-Sinoie Lake complex (RSL) in the Danube Delta (Black Sea coast, Romania), a dynamic coastal lake system hosting unique Pontocaspian mollusc species that are now severely under threat. The Pontocaspians refer to an endemic species group that evolved in the Black Sea and Caspian Sea basins under reduced salinity settings over the past few million years. The natural, pre-industrial RSL contained a salinity gradient from fresh to mesohaline (18 ppm), until human interventions reduced the inflow of mesohaline Black Sea water into the lake system. We reconstruct the evolution of the RSL over the past 2000 years from integrated sedimentary facies and faunal analyses based on 11 age-dated sediment cores and investigate the response of mollusc species and communities to those past environmental changes. Three species associations (marine, Pontocaspian, freshwater) exist and their spatiotemporal shifts through the system are documented. Variable salinity gradients developed, with marine settings (and faunas) dominating in the southern part of the system and freshwater conditions (and faunas) in the northern and western parts. Pontocaspian species have mostly occurred in the centre of the RSL within the marine–freshwater salinity gradient. Today, freshwater species dominate the entire system, and only a single Pontocaspian species (Monodacna colorata) is found alive. We show that the human-induced reduced marine influence in the system has been a major driver of the decline of the endemic Pontocaspian biota. It urges for improved conservation actions by re-establishing a salinity gradient in the lake system to preserve these unique species.

Environmental variation vs co-occurrence of two fish families (Gerreidae and Ariidae) in Terminos Lagoon, Campeche, Mexico

2021 ◽  
Vol 3 (1) ◽  
pp. 5-22
Author(s):  
Domingo Flores-Hernández ◽  
Julia Ramos-Miranda ◽  
Luis Amado Ayala-Pérez ◽  
Francisco Gómez Criollo
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Anthropogenic Activities ◽  
Salinity Gradient ◽  
Null Model ◽  
Terminos Lagoon ◽  
Southern Gulf Of Mexico ◽  
Taxonomic Groups ◽  
And Function ◽  
Abundance And Distribution

Terminos Lagoon is recognized as an ecosystem of great diversity and productivity in the southern Gulf of Mexico. It is also the site of various anthropogenic activities in the lagoon as well as in its surroundings. In addition, in recent years this lagoon has showed variations in temperature and salinity as a result of global warming and/or watershed management. This has generated variations in the structure and function of fish communities, among other taxonomic groups. IIn this work, we analyze the changes in abundance and distribution associated with modifications in the salinity of fish species from two key families (Ariidae y Gerreidae) during the years 1980, 1998, and 2011. Salinity is analyzed in the three periods (ANOVA, Tukey (HSD); the abundance of species, environmental breadth according to salinity (Levins Index), environmental overlap (Pianka Index), and co-occurrence (C-score) are also analyzed. Statistical differences were tested using the null model. The results showed high variability in salinity, with a tendency to increase during the studied period with 24.7, 27.9, and 28.4 UPS for each year, respectively (p < 0.0001). The abundance of both families increased from 1980 to 1998 and decreased in 2011 (82% for Ariidae and 62% for Gerreidae). The C-score ranged from 1.07 in 1980 to 0.78 in 1998 and 2.71 in 2011. The observed averages were significantly lower than the simulated average (P <0.0001). In conclusion, the increase in salinity is probably one of the causes of a variation in the abundance of fish species. According to a possible more limited competition for space, fish abundance and C-score fluctuated inversely, indicating a trend towards a more generalist fish community. Keywords: Environmental breadth, environmental overlapping, co-ocurrence, and salinity gradient.

Spatial patterns and seasonality in the epibenthic communities of the Westerschelde (Southern Bight of the North Sea)

2000 ◽  
Vol 80 (1) ◽  
pp. 27-36 ◽  
Author(s):  
K. Hostens
Keyword(s):  
Longitudinal Axis ◽  
Common Species ◽  
Freshwater Species ◽  
Low Oxygen ◽  
Southern Bight ◽  
The North ◽  
Westerschelde Estuary ◽  
Large Numbers ◽  
Mesohaline Zone ◽  
Short Time

Beamtrawl samples were taken monthly between January 1988 and December 1989 in 14 subtidal stations along the longitudinal axis of the Westerschelde Estuary. The estuary harboured high densities of epibenthic species (total average of 2250 ind 1000 m−2). Only 37 fish species were recorded and three mobile macroinvertebrate species were quantified. Seventeen epibenthic species were common, only eight of which were very abundant. An overall dominance of the brown shrimp Crangon crangon was noted. The near absence of anadromous and freshwater species was correlated with the low oxygen concentrations upstream the Dutch–Belgian border. The epibenthic species could be divided into a polyhaline and a mesohaline community along the main salinity–oxygen–turbidity gradients of the estuary. The mesohaline zone was characterized by higher densities and biomasses for shrimps, gobies and flatfish. The spatial structure in the epibenthic community of the polyhaline zone was more influenced by the watermasses from the sea and inflowing channels, and was correlated with the degree of exposure (current velocities and tides). A classification is proposed, based on the season in which the epibenthic species occur in the estuary, and on their life stages and abundances during that period. The monthly data demonstrate that while the eight abundant epibenthic species were generally present throughout the year (summer or winter resident), the majority tended to appear in the Westerschelde at varying times (summer, winter or bimodal) and often remained in large numbers (nine common species) for only a short time. The fact that mainly juveniles were recorded in the higher density-classes, suggests that the Westerschelde Estuary still acts as a nursery area for many epibenthic species.

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