Dependence of efficiency of natural fish reproduction in water bodies of Kazakhstan from water level

Author(s):  
K.B. Isbekov ◽  
E.V. Kulikov ◽  
S.Zh. Asylbekova

The article deals with the relationship between the hydrological regime of water bodies and the efficiency of fish reproduction. The hydrological regime of water bodies in years of different water content influences the reproduction and, accordingly, the quantitative and qualitative composition of ichthyocenoses. The easiest way to assess the efficiency of fish reproduction is by such an indicator as the productivity of juveniles, i.e. the number of juvenile fish per unit area or volume. The material for this work was carried out in large fishing reservoirs of the Republic of Kazakhstan in the process of fishery research (2013–2018). Comparison of hydrological parameters and productivity of juveniles by years shows their relationship. Correlation coefficient between water content (runoff) of the river Zhaiyk and juvenile yield +0.73 (data set for 11 years, reliable for the level of significance p = 0.01). The yield of juvenile fish from Lake Balkhash has a high correlative dependence on the inflow of water into the lake (r = +0.826) (massif 2013–2018, reliable for the level of significance p = 0.05). Correlation analysis showed that the productivity of juvenile fish in the Kapshagai reservoir has an average degree of dependence on water content (average annual level) (r = +0.641, reliable for the level of significance p = 0.05). Regular relationships between the water regime and the efficiency of reproduction (productivity of juveniles) of fish have been established. The efficiency of natural reproduction of commercial fish species in modern conditions of the water regime, water withdrawal for economic needs and the impact of fishing is significantly reduced, but with the implementation of the reclamation measures proposed in the work, its partial restoration is possible.

Author(s):  
Saule Zhangirovna Asylbekova ◽  
Kuanysh Baibulatovich Isbekov ◽  
Evgeniy Vyacheslavovich Kulikov

The hydrological regime of water reservoirs in different years has a decisive impact on the abundance of commercial fish stocks and the quality of ichthyocenoses. In this connection in 2015-2016 there was conducted a retrospective analysis and ranking of hydrological regime impact on these factors. The paper gives evaluation of catches and fish stocks under different scenarios of water availability in the main fishing ponds of the Republic of Kazakhstan that give about 80% of the annual fish catch of the country (except the Caspian Sea). There were analyzed 2000 factors of hydrological regime (water level, annual discharge) and 1845 factors of fishing stocks (catches, abundance, fish biomass). The paper determines the critical characteristics of water availability for fish stocks. There have been proposed a number of administrative decisions and actions in case if water content would approach to the critical level. Among them: limitation of fish catches in the following year; widening zones restricted for fishing; intensification of safety measures of the fish young in residual ponds during arid periods; introduction of catch standards for a unit of fishing effort in low-water years, high-water years and years with normal water level in rivers.


Author(s):  
Arvydas Povilaitis ◽  
Erik P. Querner

The Žuvintas Lake, located in southern Lithuania in the basin of the Dovine River is one of the biggest lakes and the oldest natural reserves of the country. However, the changes in the hydrology of the Dovine River basin, caused by large‐scale melioration and water management works carried out in the 20th century, have resulted in significant alteration of hydrological regime and decrease in biodiversity of the Žuvintas Lake and surrounding wetlands. In order to prevent the ongoing deterioration of the Lake and wetlands solutions have to be found. Therefore, various scenarios have been analysed to evaluate the impact of water management alternatives. For these scenarios the physically‐based distributed parameter model SIMGRO was used. The results have shown that natural water regime in the Žuvintas Lake is hardly reversible. However, the replacement of sluice‐gates implemented at the outlet of the Žuvintas Lake by overflow weir as well as the blocking of drainage ditches and the removal of scrubs and trees in the wetlands surrounding the Lake can be highly successful measures to improve hydrological conditions. Santrauka Dovinės upės (dešinysis Šešupės upės intakas) baseine yra seniausias Lietuvoje Žuvinto biosferos rezervatas ir kitos europinės svarbos saugomos teritorijos. Tose vietose hidrologinis režimas tiesiogiai reguliuojamas šešiose vietose pastatytais reguliavimo šliuzais. Šiuo metu poreikio reguliuoti nėra, todėl darbe analizuojamos natūralaus vandens režimo atkūrimo galimybės Žuvinto ežere ir aplinkinėse pelkėse. Tam buvo taikytas matematinio modeliavimo metodas naudojant pasiskirsčiusių parametrų SIMGRO modelį. Ankstesni tyrimai parodė, kad atkurti natūralų hidrologinį režimą vien panaikinus reguliavimo šliuzą žemiau Žuvinto ežero, negalima. Tai sunaikintų ežerą ir neigiamai paveiktų požeminio vandens režimą Žuvinto ir Amalvos pelkių komplekse. Siekiant bent dalinio vandens režimo natūralizavimo reguliavimo šliuzą siūloma rekonstruoti į slenkstinę nuopylą įrengiant žuvitakį. Žuvinto ir Amalvos pelkių masyve požeminio vandens režimui pagerinti rekomenduojama pašalinti ten augančią sumedėjusią augaliją ir apypelkio teritorijose patvenkti melioracijos griovius. Pateikiamas tokių priemonių galimas poveikis Žuvinto ežero ir aplinkinių pelkių hidrologiniam režimui. Peзюме Водный режим бассейнa реки Довине в южной части Литвы в прошлом столетии был подвержен важным изменениям. Там находится старый заповедник Литвы – озеро Жувинтас c близлежащими болотaми. В статье представлен сценарий по восстановлению водного режима в озере Жувинтас и окружающих болотах. Для исследования была применена математическая модель SIMGRO. Результаты показали, что полное восстановление гидрологического режима в озере невозможно. Для улучшения водного режима предложен ряд мер.


2019 ◽  
Vol 96 (1) ◽  
Author(s):  
James S Griffin ◽  
Loren A Haug ◽  
Vivien A Rivera ◽  
Liliana M Hernandez Gonzalez ◽  
John J Kelly ◽  
...  

ABSTRACT While the impacts of soil moisture on soil microbiome diversity and composition are well characterized, the influence of hydrological regime has been overlooked. As precipitation patterns are altered by climate change, understanding the impact of soil hydrology on community structure and function is critical. In this work, water level was continuously monitored for over a year in a Midwestern prairie-wetland at 10 cm depth increments up to a depth of 120 cm in 10 locations. We analyzed microbiome composition and edaphic factors in soil cores collected from this unique spatially distributed, longitudinal data set. We demonstrate that the fraction of time that each sample was inundated explains more variability in diversity and composition across this site than other commonly assessed edaphic factors, such as soil pH or depth. Finally, we show that these compositional changes influence abundance of ammonia oxidizers. The observed patterns in community composition and diversity are fundamentally regulated by the interaction of water with a structured landscape, particularly an elevated sand ridge characterized by drier conditions and a lower-lying wetland with more clayey soils. Similar processes are generally expected to influence the biogeography of many terrestrial environments, as morphology, hydrology and soil properties generally co-vary.


Author(s):  
Natalia Ivanovna Chavychalova ◽  
Dina Germanovna Taradina ◽  
O.M. Vasilchenko ◽  
Raigul Sadyakhovna Mukhanova

A retrospective review of the main factors that caused the decline in the reproduction of semi-passable fish in the lower reaches of the Volga River is given. Long-term data on the yield of juvenile semi-passable and river fish are presented, on the basis of which the current state of natural reproduction of roach, carp is estimated as low; bream, bluefin and perch — satisfactory; crucian carp, gaster and rudd — safe. Overregulation of the Volga River flow near Volgograd violated the natural conjugacy of water and temperature regimes. In the regulated period, the timing of the onset of spawning temperature in most cases is ahead of the flooding of the strips. The lag of the delta spawning grounds begins when the runoff is less than 120 km³ and reaches the maximum values (up to 27 days) in years with extremely low water content. The delay in flooding of spawning grounds in conditions of unsatisfactory water content leads to the accumulation of producers in limited areas of strips and simultaneous spawning of fish with different ecology. This leads to increased food competition of the larvae and reduced survival. After the flow was regulated, the rates of rise and fall of the hollow waters increased by 2 times, the hatching of the larvae, as a rule, coincided with the onset of the flow of the hollow waters. The mass removal of larvae into the delta watercourses at the early stages of ontogenesis, due to their lack of viability in river conditions, leads to a decrease in the productivity of spawning grounds. In the modern period (2003– 2019), due to the predominance of unfavorable hydrological regime, the duration of high water and flooding of the poloi years, and in order to clarify the yield of juvenile fish in the lower reaches of the Volga, its accounting was carried out not only in the poloi of the delta, but also in the coastal watercourses (where a large number of larvae and fry that rolled off the poloi and from local spawning), in the kultuch zone and on the poloi of the lower zone of the Volga-Akhtuba floodplain.


2021 ◽  
Vol 273 ◽  
pp. 03007
Author(s):  
Dmitry Larin ◽  
Evgeny Mikhaylov ◽  
Elena Staseva

Intensive economic use of small rivers and channel water bodies leads to their pollution and siltation. The anthropogenic impact on aquatic ecosystems negatively affects the state of the fish industry, which leads to a reduction in the spawning fund, deterioration of the conditions for reproduction and survival of juveniles. Violation of the existing conditions for the habitat and reproduction of aquatic organisms leads to a decrease in the productivity of water bodies and the loss of their fishery value. The inflow from the catchment area of solid and liquid runoff containing organic matter, oil products and other impurities of anthropogenic and technogenic origin leads to irreversible entry, siltation and shallowing of small rivers and channel water bodies. The restoration of the disturbed hydrological regime of water bodies by means of reclamation works contributes to the restoration of natural spawning grounds for commercial fish species, an increase in yield and productivity.


Crisis ◽  
2018 ◽  
Vol 39 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Kuan-Ying Lee ◽  
Chung-Yi Li ◽  
Kun-Chia Chang ◽  
Tsung-Hsueh Lu ◽  
Ying-Yeh Chen

Abstract. Background: We investigated the age at exposure to parental suicide and the risk of subsequent suicide completion in young people. The impact of parental and offspring sex was also examined. Method: Using a cohort study design, we linked Taiwan's Birth Registry (1978–1997) with Taiwan's Death Registry (1985–2009) and identified 40,249 children who had experienced maternal suicide (n = 14,431), paternal suicide (n = 26,887), or the suicide of both parents (n = 281). Each exposed child was matched to 10 children of the same sex and birth year whose parents were still alive. This yielded a total of 398,081 children for our non-exposed cohort. A Cox proportional hazards model was used to compare the suicide risk of the exposed and non-exposed groups. Results: Compared with the non-exposed group, offspring who were exposed to parental suicide were 3.91 times (95% confidence interval [CI] = 3.10–4.92 more likely to die by suicide after adjusting for baseline characteristics. The risk of suicide seemed to be lower in older male offspring (HR = 3.94, 95% CI = 2.57–6.06), but higher in older female offspring (HR = 5.30, 95% CI = 3.05–9.22). Stratified analyses based on parental sex revealed similar patterns as the combined analysis. Limitations: As only register-­based data were used, we were not able to explore the impact of variables not contained in the data set, such as the role of mental illness. Conclusion: Our findings suggest a prominent elevation in the risk of suicide among offspring who lost their parents to suicide. The risk elevation differed according to the sex of the afflicted offspring as well as to their age at exposure.


Author(s):  
Gražina ŽIBIENĖ ◽  
Alvydas ŽIBAS ◽  
Goda BLAŽAITYTĖ

The construction of dams in rivers negatively affects ecosystems because dams violate the continuity of rivers, transform the biological and physical structure of the river channels, and the most importantly – alter the hydrological regime. The impact on the hydrology of the river can occur through reducing or increasing flows, altering seasonality of flows, changing the frequency, duration and timing of flow events, etc. In order to determine the extent of the mentioned changes, The Indicators of Hydrologic Alteration (IHA) software was used in this paper. The results showed that after the construction of Angiriai dam, such changes occurred in IHA Parameters group as: the water conditions of April month decreased by 31 %; 1-day, 3-days, 7-days and 30-days maximum flow decreased; the date of minimum flow occurred 21 days later; duration of high and low pulses and the frequency of low pulses decreased, but the frequency of high pulses increased, etc. The analysis of the Environmental Flow Components showed, that the essential differences were recorded in groups of the small and large floods, when, after the establishment of the Šušvė Reservoir, the large floods no longer took place and the probability of frequency of the small floods didn’t exceed 1 time per year.


Author(s):  
Natalia Kuczyńska-Kippen ◽  
Barbara Nagengast ◽  
Tomasz Joniak

The impact of biometric parameters of a hydromacrophyte habitat on the structure of zooplankton communities in various types of small water bodies


2013 ◽  
Vol 99 (4) ◽  
pp. 40-45 ◽  
Author(s):  
Aaron Young ◽  
Philip Davignon ◽  
Margaret B. Hansen ◽  
Mark A. Eggen

ABSTRACT Recent media coverage has focused on the supply of physicians in the United States, especially with the impact of a growing physician shortage and the Affordable Care Act. State medical boards and other entities maintain data on physician licensure and discipline, as well as some biographical data describing their physician populations. However, there are gaps of workforce information in these sources. The Federation of State Medical Boards' (FSMB) Census of Licensed Physicians and the AMA Masterfile, for example, offer valuable information, but they provide a limited picture of the physician workforce. Furthermore, they are unable to shed light on some of the nuances in physician availability, such as how much time physicians spend providing direct patient care. In response to these gaps, policymakers and regulators have in recent years discussed the creation of a physician minimum data set (MDS), which would be gathered periodically and would provide key physician workforce information. While proponents of an MDS believe it would provide benefits to a variety of stakeholders, an effort has not been attempted to determine whether state medical boards think it is important to collect physician workforce data and if they currently collect workforce information from licensed physicians. To learn more, the FSMB sent surveys to the executive directors at state medical boards to determine their perceptions of collecting workforce data and current practices regarding their collection of such data. The purpose of this article is to convey results from this effort. Survey findings indicate that the vast majority of boards view physician workforce information as valuable in the determination of health care needs within their state, and that various boards are already collecting some data elements. Analysis of the data confirms the potential benefits of a physician minimum data set (MDS) and why state medical boards are in a unique position to collect MDS information from physicians.


Author(s):  
I. Saakian ◽  
Aleksandr, Grigor’ev ◽  
E. Kravets ◽  
E. Rudakov ◽  
A. Faddeev ◽  
...  

Выполнен анализ действующей редакции Методики разработки нормативов допустимых сбросов веществ и микроорганизмов в водные объекты для водопользователей , утвержденной приказом Минприроды России от 17 декабря 2007 г. 333, на предмет непротиворечивости и соответствия нормам водоохранного законодательства. Выявлена неопределенность применения Методики в условиях воздействия на качество воды природных и антропогенных факторов, не зависящих от конкретного водопользователя. Положения Методики противоречат принципам нормирования воздействия на водные объекты на основе наилучших доступных технологий, что было показано на примерах утвержденных технологических показателей содержания загрязняющих веществ в сточных водах различных отраслей промышленности. Анализ системы нормирования допустимых воздействий на водные объекты и географической дифференциации нормативов качества воды в пределах Российской Федерации вместе с системой целевых показателей качества воды также показал несоответствие Методики основным принципам водоохранного законодательства.The analysis of the current edition of the Methods of developing standards for permissible discharges of substances and microorganisms into water bodies for water users , approved by the Order of the Ministry of Natural Resources of Russia dated December 17, 2007 No. 333 for consilience and compliance with the regulations of the water protection legislation, is carried out. Uncertainty of the application of the Methods in the conditions of the impact of natural and anthropogenic factors that are independent of a specific water user on the quality of water has been identified. The provisions of the Methods contradict the principles of regulating the impact on water bodies based on the best available technologies shown on the examples of approved process indicators of the concentrations of various industrial pollutants in wastewater. An analysis of the system of regulating the permissible impact on water bodies and the geographical differentiation of water quality standards within the boundaries of the Russian Federation, together with the system of water quality targets, also showed that the Methods do not comply with the basic principles of the water protection legislation.


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