scholarly journals Characterization of the Fish Population in the Southwestern Part of the Onega Lake (Karelia) Based on the Results of Long-Term Monitoring

2020 ◽  
Vol 8 (4) ◽  
pp. 1510-1515
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Fish Population ◽  
The Arctic ◽  
Coregonus Lavaretus ◽  
Southwestern Part ◽  
Onega Lake ◽  
Late Tertiary ◽  
Commercial Species

The results of the long-term ichthyological studies of the southwestern part (the Sheltozero – Brusno region) of the Onega Lake performed as part of the environmental monitoring have been presented. This is one of the most productive and clean areas in the lake. The fish population of the southwestern part of the Onega Lake includes 20 fish species that are representatives of 10 families belonging to six faunistic complexes. By the number of the species, the Carp family dominates. By the number of the species in this area of the lake, the Arctic freshwater, the boreal plain, and the boreal foothill complexes are equally important. The species of the freshwater Pontian, the Arctic marine, and the ancient Late Tertiary complexes together amount to no more than 25 % of the total population. In the southwestern region of the lake, there are many valuable commercial species (freshwater salmon (Salmo salar Linnaeus, 1758), lavaret (Coregonus lavaretus lavaretus (Linnaeus, 1758)), pikeperch (Sander lucioperca (Linnaeus, 1758)), pike (Esox lucius Linnaeus, 1758), etc. Smelt (Osmerus eperlanus (Linnaeus, 1758)) and vendace (Coregonus albula (Linnaeus, 1758)) are the most commercially valuable (75 – 85 %). The population-ecological analysis has shown a relatively good state of most studied fish species. For maintaining the existing structure and state of the fish population in the southwestern part of the Onega Lake, a set of measures is required, including the preservation and improvement of the fish habitat, the conditions for the fish reproduction and feeding; toughening the protective measures during periods with a decrease in the number of fish species; regulation of fishing, and increasing the amount of fish artificial reproduction, rearing, and releasing into the lake.

Polyculture in fish farming as a method of preventing fish diseases

2021 ◽  
pp. 30-40
Author(s):  
Grigory Emelyanovich Servetnik
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Fish Farming ◽  
Natural Food ◽  
Total Biomass ◽  
Fish Farms ◽  
Fish Diseases ◽  
Host Body ◽  
Contagious Diseases

Methods of prevention of fish diseases are aimed at destroying parasites in the host body and in the fish habitat — in the reservoir (chemoprophylaxis, increasing fish resistance), at preventing parasites from entering the reservoir (limiting the import of fish, import of healthy fish, quarantine measures, etc.), as well as preventing their spread and entry into the host body. It is shown that polyculture is not only the most effective method of using the natural forage base of the reservoir and, as a result, increasing fish productivity, but also a means of preventing mass infectious and other fish diseases. To prevent mass infectious diseases of fish and death from them both in safe and unfavorable ponds of carp fish farms, it is advisable to grow other fish species together with carp that do not suffer from diseases peculiar to carp. As a result, so-called sparse species plantings of fish are created in the ponds, while the total biomass remains high. At the same time, the natural food supply of ponds is most fully used and a kind of biological buffer is created that prevents the emergence and spread of contagious diseases. Polyculture can play a particularly important role in pond farms that already have certain problems with rubella, filometroidosis, botryocephalosis, carp pox, etc. Long-term studies of breeding herds in pond farms have shown that most of them have single foci of diseases, which, if there are optimal conditions for the pathogen, are ready to immediately respond with an outbreak of the disease or are generally quarantined for a particular fish disease. When determining the objects of polyculture, it is necessary to reduce the proportion of fish species that have a significant number of common diseases.

scholarly journals Importance of considering riparian vegetation requirements for the long-term efficiency of environmental flows in aquatic microhabitats

2017 ◽  
Vol 21 (11) ◽  
pp. 5763-5780 ◽  
Author(s):  
Rui Rivaes ◽  
Isabel Boavida ◽  
José M. Santos ◽  
António N. Pinheiro ◽  
Teresa Ferreira
Keyword(s):  
Fish Species ◽  
Riparian Vegetation ◽  
Environmental Flows ◽  
Fish Habitat ◽  
Natural Habitat ◽  
River Channel ◽  
Habitat Availability ◽  
Hydraulic Characteristics ◽  
Vegetation Development

Abstract. Environmental flows remain biased toward the traditional biological group of fish species. Consequently, these flows ignore the inter-annual flow variability that rules species with longer lifecycles and therefore disregard the long-term perspective of the riverine ecosystem. We analyzed the importance of considering riparian requirements for the long-term efficiency of environmental flows. For that analysis, we modeled the riparian vegetation development for a decade facing different environmental flows in two case studies. Next, we assessed the corresponding fish habitat availability of three common fish species in each of the resulting riparian landscape scenarios. Modeling results demonstrated that the environmental flows disregarding riparian vegetation requirements promoted riparian degradation, particularly vegetation encroachment. Such circumstance altered the hydraulic characteristics of the river channel where flow depths and velocities underwent local changes of up to 10 cm and 40 cm s−1, respectively. Accordingly, after a decade of this flow regime, the available habitat area for the considered fish species experienced modifications of up to 110 % when compared to the natural habitat. In turn, environmental flows regarding riparian vegetation requirements were able to maintain riparian vegetation near natural standards, thereby preserving the hydraulic characteristics of the river channel and sustaining the fish habitat close to the natural condition. As a result, fish habitat availability never changed more than 17 % from the natural habitat.

scholarly journals Dynamics of the fish population of the high floodplain lake of the Oka River basin by the example of the Lake Erus, Ryazan Oblast, Russia

2020 ◽  
Vol 3 (4) ◽  
Author(s):  
Elena Yu. Ivancheva ◽  
Victor P. Ivanchev ◽  
Irina Yu. Lychkovskaya
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Fish Population ◽  
Species Structure ◽  
Ecological Capacity ◽  
Number Of Factors ◽  
Physico Chemical ◽  
Forest Lake ◽  
Significant Factors

The long-term dynamics of the fish population was studied in the forest lake of the high floodplain of the Oka River, located in the southeastern Meshchera Lowlands. The maximum ecological capacity of the lake is fifteen fish species and the minimum, three fish species. The dynamics of the composition and species structure of the fish community depends on a number of factors. The most significant factors are the physico-chemical characteristics of the lake, the level of spring floods, and the interactions between aboriginal and invasive species.

scholarly journals Biodiversity of fish species of Arut-Kumai Peat Waters, West Kotawaringin District, Central Kalimantan

2019 ◽  
Vol 19 (2) ◽  
pp. 315
Author(s):  
Eddy Santoso ◽  
Gema Wahyudewantoro
Keyword(s):  
Fish Species ◽  
Fish Habitat ◽  
Buffer Zone ◽  
Fish Population ◽  
Fish Traps ◽  
Fish Samples ◽  
Wildlife Reserve ◽  
The City ◽  
Peat Area ◽  
Fish Species Diversity

The peat waters area such as swamps, lakes and rivers, are essential habitat for many fish which consumed by Arut-Kumai residents who live in the city of Pangkalan Bun. Fish species diversity and its potential are not yet widely known, therefore it needs to be revealed. The research aims to reveal fish biodiversity and its potential in the peat waters of the Arut Lamandau-Kumai River Basin, west Kotawaringin Regency. The study was conducted in October-December 2017. Fish samples were captured by using cast net, gill nets, hooks and rods, fish traps. During the study period, a number of 95 fish species belonging to 50 genera, 23 families dan 6 orders were collected. The most common family was Cyprinidae, followed by Siluridae, Osphronemidae, Chanidae dan Bagridae. Dominant genera were Osteochilus and Rasbora, Kyrptopterus, Betta Channa. As many as 70 species as consumption fish, 53 species as ornamental fish, while 56 species have the potential as aquaculture fish. The fish habitat in the Arut-Lamandau river is a peat area that stretches in the buffer zone of the eastern part of the Lamandau River Wildlife Reserve, that has been transformed into an oil palm plantation. In addition, logging activity is occurred mainly in peat ecosystem areas in production forest areas. These activities are thought to cause a reduction fish population in Arut-Kumai peat waters.

scholarly journals Importance of considering riparian vegetation requirements for the long-term efficiency of environmental flows

2017 ◽  
Author(s):  
Rui Rivaes ◽  
Isabel Boavida ◽  
José M. Santos ◽  
António N. Pinheiro ◽  
Teresa Ferreira
Keyword(s):  
Fish Species ◽  
Riparian Vegetation ◽  
Environmental Flows ◽  
Fish Habitat ◽  
Natural Habitat ◽  
Life Cycles ◽  
River Channel ◽  
Habitat Availability ◽  
Hydraulic Characteristics

Abstract. Environmental flows remain biased toward the traditional biological group of fish species. Accordingly, these flows ignore the inter-annual flow variability that rules species with longer life cycles, thereby disregarding the long-term perspective of the riverine ecosystem. We analyzed the influence of considering riparian requirements for the long-term efficiency of environmental flows. For that analysis, we modeled the riparian vegetation development for a decade facing different environmental flows in two case studies. Next, we assessed the corresponding fish habitat availability of three common fish species in each of the resulting riparian habitat scenarios. Modeling results demonstrated that the environmental flows disregarding riparian vegetation requirements promoted riparian degradation, particularly vegetation encroachment. Such circumstance altered the hydraulic characteristics of the river channel where flow depths and velocities underwent changes up to 10 cm and 40 cm s−1, respectively. Accordingly, after a decade of this flow regime, the available habitat area for the considered fish species experienced modifications in absolute from 18.16 % to 109.75 % compared to the natural habitat. In turn, environmental flows regarding riparian vegetation requirements were able to maintain riparian vegetation near natural standards, thereby preserving the hydraulic characteristics of the river channel and sustaining the fish habitat close to the natural condition. As a result, fish habitat availability never changed more than 16.17 % from the natural habitat.

scholarly journals Hydrographic variability in Icelandic waters during recent decades and related changes in distribution of some fish species

2012 ◽  
Vol 69 (5) ◽  
pp. 816-825 ◽  
Author(s):  
Héðinn Valdimarsson ◽  
Olafur S. Astthorsson ◽  
Jonbjorn Palsson
Keyword(s):  
Fish Species ◽  
Saline Water ◽  
Shelf Area ◽  
Seasonal Time Series ◽  
Shelf Seas ◽  
Commercial Species ◽  
Area North ◽  
First Time ◽  
Icelandic Waters

Abstract Valdimarsson, H., Astthorsson, O. S., and Palsson, J. 2012. Hydrographic variability in Icelandic waters during recent decades and related changes in distribution of some fish species. – ICES Journal of Marine Science, 69: 816–825. Seasonal time-series of temperature and salinity around Iceland have been collected, with repeat observations at stations, since the start of the 1970s. After fairly cold years during the early 1990s, a reversal occurred during the mid-1990s and the period from 1996 to 2010 was one with warmer, more saline water in shelf seas around Iceland. Temperatures and salinities have been frequently above the long-term mean in the waters to the south and west of the country, and these conditions have also influenced the shelf area north of the country. Marked changes have also been observed in the distribution of many fish species during this warm period. Southern commercial species have extended farther north (e.g. haddock, monkfish, mackerel), a northern species is retreating (capelin), rare species and vagrants have been observed more frequently (e.g. greater fork beard, blue antimora, snake pipefish, sea lamprey, Ray's bream), and 31 species, from both shelf and oceanic waters, have been recorded for the first time since 1996. The most obvious explanation for these changes in the ecosystem has to be the warming of 1–2°C in the waters south and west of Iceland during the past 15 years.

Diatoms and aquatic palynomorphs in the sediments of the Eurasian Arctic seas and their significance for paleooceanological investigations in the Arctic

2019 ◽  
pp. 246-251
Author(s):  
Yelena I. Polyakova ◽  
Yekaterina I. Novichkova ◽  
Tatiana S. Klyuvitkina ◽  
Elizaveta A. Agafonova ◽  
Irina M. Kryukova
Keyword(s):  
Bering Sea ◽  
Surface Sediments ◽  
Sea Water ◽  
The Arctic ◽  
Marginal Filter ◽  
Arctic Seas ◽  
Hydrological Parameters ◽  
The Arctic Ocean ◽  
Long Term Studies

Presented the results of long-term studies of diatoms and aquatic palynomorphs in surface sediments of the Arctic seas and the possibility of their use for the reconstructions of paleocirculation water masses, advection of Atlantic and Bering sea water into the Arctic ocean, changes in the river runoff to the seas, sedimentary processes in the marginal filter of the largest rivers, seasonal sea ice cover and other hydrological parameters.

SEEDING DENSITY OF DIFFERENT FISH SPECIES IN POLYCULTURE

2017 ◽  
pp. 74-79
Author(s):  
Yuriy Borisovich Lvov
Keyword(s):  
Fish Species ◽  
Silver Carp ◽  
Seeding Density ◽  
Habitat Conditions ◽  
Method Of Calculation ◽  
Fish Breeding ◽  
Trophic Preferences ◽  
Breeding Zone ◽  
Practical Progress

The article touches upon the principles, biological basics and practical progress of introduction of specific and age polyculture of fishes. Using the results of the analysis of literary and long-term native data, there has been offered the gradation of 12 fish species from different families by resistance to habitat conditions. Crucian ( Carassius gibelio ) has been chosen as the most sustainable object of cultivation. There has been taken an attempt to calculate the number of seeding different fish species in polyculture taking into account their physiological features is made. Subject to specific physiological features of the studied species, there was carried out recalculation of their natural reproductive performance in different fish-breeding zones, which is traditionally carried out for a carp ( Cyprinus carpio ). In particular, in the second fish-breeding zone with area of 1 hectare it is possible to breed 120 kg of carp, or 150 kg of crucian, or 75 kg of silver carp ( Hypophthalmichthys ). Overall productivity is made up of a share of fishes in polyculture, but taking into account tolerance of species, it can be lower than productivity calculated for carp. The method of calculation and formulas which give the chance to determine seeding density of fish species for breeding in polyculture have been offered. This technique makes it possible to use trophic preferences and consider tolerance of each species to the conditions of breeding areas.

Trends and Prospects of Development of the Oil and Gas Sector in the Context of Digitalization

2020 ◽  
Vol 26 (1) ◽  
pp. 35-45 ◽  
Author(s):  
A. G. Kazanin
Keyword(s):  
Oil And Gas ◽  
Digital Technologies ◽  
Oil And Gas Industry ◽  
Global Market ◽  
The Arctic ◽  
Business And Society ◽  
Gas Industry ◽  
Exploration And Production ◽  
Oil And Gas Sector

The modern oil and gas industry is heavily dependent on the processes and trends driven by the accelerating digitalization of the economy. Thus, the digitalization of the oil and gas sector has become Russia’s top priority, which involves a technological and structural transformation of all production processes and stages.Aim. The presented study aims to identify the major trends and prospects of development of the Russian oil and gas sector in the context of its digitalization and formation of the digital economy.Tasks. The authors analyze the major trends in the development of the oil and gas industry at a global scale and in Russia with allowance for the prospects of accelerated exploration of the Arctic; determine the best practices of implementation of digital technologies by oil and gas companies as well as the prospects and obstacles for the subsequent transfer of digital technologies to the Russian oil and gas industry.Methods. This study uses general scientific methods, such as analysis, synthesis, and scientific generalization.Results. Arctic hydrocarbons will become increasingly important to Russia in the long term, and their exploration and production will require the implementation of innovative technologies. Priority directions for the development of many oil and gas producers will include active application of digital technologies as a whole (different types of robots that could replace people in performing complex procedures), processing and analysis of big data using artificial intelligence to optimize processes, particularly in the field of exploration and production, processing and transportation. Digitalization of the oil and gas sector is a powerful factor in the improvement of the efficiency of the Russian economy. However, Russian companies are notably lagging behind in this field of innovative development and there are problems and high risks that need to be overcome to realize its potential for business and society.Conclusions. Given the strategic importance of the oil and gas industry for Russia, its sustainable development and national security, it is recommendable to focus on the development and implementation of digital technologies. This is crucial for the digitalization of long-term projection and strategic planning, assessment of the role and place of Russia and its largest energy companies in the global market with allowance for a maximum number of different internal and external factors.

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