THE NUMBER AND QUALITATIVE CHARACTERISTICS OF FRY FISH IN SHALLOW COASTAL WATERS OF THE VOLGA IN THE SUMMER-AUTUMN PERIOD OF 2012

2017 ◽  
pp. 65-73
Author(s):  
Edward Vladimirovich Nikitin
Keyword(s):  
Fish Species ◽  
Coastal Waters ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Volga River ◽  
Commercial Fish ◽  
Autumn Period ◽  
Fish Juveniles ◽  
Qualitative Characteristics ◽  
Shallow Coastal Waters

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.

scholarly journals TO THE FAUNA OF BIVALVE MOLLUSCS OF THE DAGESTAN COAST OF THE CASPIAN SEA

2018 ◽  
Vol 13 (2) ◽  
pp. 9-21 ◽  
Author(s):  
Marina V. Khlopkova ◽  
Magomedzagid K. Guseynov ◽  
Kais M. Guseynov ◽  
Aysha Sh. Gasanova
Keyword(s):  
Fish Species ◽  
Caspian Sea ◽  
Food Resource ◽  
Fish Fauna ◽  
Bivalve Mollusks ◽  
The Caspian Sea ◽  
Commercial Fish ◽  
Main Food ◽  
The Third ◽  
The Individual

Aim. The aim is to study bivalve mollusks of the Dagestan zone of the Caspian Sea as the main feed for all the fish fauna in modern conditions. Material and methods. For the study, are used the materials received in the period of spring-autumn 2015-2017. The collection of material and data processing was carried out according to traditional methods. For the study of nutrition, 30 specimens of each fish species were opened. Such feeding characteristics as the composition of food and the ratio of feed components are given. In the study of shells of bivalve mollusks, the following morphological parameters were measured: length (L), height (H), convexity (Con.), in accordance with the most common measurement technique. Were calculated the allometric coefficients for each year of the life of the individual: the coefficient of elongation (the ratio of height to length), the convexity coefficient (the ratio of convexity to the height). Results. At all periods of the level regime, mollusks are the main food resource of the Caspian Sea. At present they form the basis of the food bolus of the investigated commercial fish species. In June 2017, 25 km north of the city of Makhachkala, after a storm, we found 109 shells of Corbicula fluminalis (O.F. Müller, 1774) (a new invasive atypical species for the investigated aquatorium), the third part of which still had the remains of the ligament. The species was the third most abundant and represented by specimens of all age stages. Conclusions. At present, there are fluctuations in the biomass of the autocolonizers Cerastoderma lamarcki (Reeve), Mytilaster lineatus (Gmelin) and Abra ovata (Philippi), as well as a significant reduction in the range of autochthonous Caspian species, mainly Didacna Eichw. Bivalve mollusks are the main food resource of the Caspian Sea. In conditions of increasing anthropogenic load, further detailed studies of the Caspian's malacofauna are needed.

scholarly journals INTERSPECIFIC NUTRITIONAL RELATIONSHIP BETWEEN CLUPEONELLA ENGRAULIFORMIS AND CLUPEONELLA CASPIA IN THE CASPIAN SEA

2019 ◽  
pp. 13-19
Author(s):  
Anna Viktorovna Mikhajlova
Keyword(s):  
Fish Species ◽  
Caspian Sea ◽  
Food Preferences ◽  
Pelagic Fish ◽  
Middle Part ◽  
Aqueous Environment ◽  
The Caspian Sea ◽  
Commercial Fish ◽  
The North ◽  
Close Relationship

Vital activity of the Caspian ichthyofauna is mainly determined by aqueous environment with its multiple factors influencing the hydrobionts’ life cycle. It is well known that in the process of evaluating the stocks of commercial fish species it is necessary to take into account supplying them with food. Trophologic studies of mature species of Clupeonella Caspia and Clupeonella Engrauliformis in the Caspian Sea make a basis for a large number of works; however, the research of food preferences of these fish species is scarce. Clupeonella Caspia inhabits the north, middle and south parts of the Caspian Sea above the 60 m isobath. Clupeonella Engrauliformis is widespread in the middle and southern parts of the Caspian Sea above the depths more than 200 m. In the course of evaluating kilka fattening in the Caspian Sea that was continued in 2011 there were estimated nutrition relations of kilka species over the many years, traced the degree of nutritional similarity and registered interspecific relationship between these pelagic fish. The results obtained have been summarized and the whole range of trophic studies has been shown. The monitoring nature of the studies allows to infer the intensive feeding of Clupeonella Caspia and Clupeonella Engrauliformis in the summer of 2011-2014 and in 2016 in the middle part of the Caspian Sea (the study of pelagic fish fatting was not conducted in 2015). The multi-year comparative analysis of Clupeonella Caspia and Clupeonella Engrauliformis nutrition demonstrated the differences of using the dominant foodstuff among planktonic invertebrates. It has been stated that the index of similarity of the food spectrum does not always have a greater degree of coincidence in close relationship of fish in a systematic respect.

scholarly journals Some commercial fish species nutrition in the Kazakhstan part of the Caspian Sea

2019 ◽  
Vol 81 (4) ◽  
pp. 78-93
Author(s):  
S. M. Shalgimbayeva ◽  
◽  
N. N. Popov ◽  
N. Ibragimova ◽  
Zh. S. Omarova ◽  
...  
Keyword(s):  
Fish Species ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Commercial Fish

INFLUENCE OF INVADER CTENOPHORAN MNEMIOPSIS LEIDYI (A. AGASSIS, 1865) ON THE GENERAL PARTS OF THE CASPIAN SEA ECCOSYSTEM

2018 ◽  
pp. 35-48
Author(s):  
Andrey Mikhailovich Kamakin ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Raisa Pavlovna Khodorevskaya
Keyword(s):  
Fish Species ◽  
Caspian Sea ◽  
Marine Mammals ◽  
Nutrient Budget ◽  
Mnemiopsis Leidyi ◽  
Ecological Problem ◽  
Annual Data ◽  
The Caspian Sea ◽  
Commercial Fish ◽  
Strategy Of Development

The article presents annual data (1999-2016) of ecological surveillance on the influence of newish for the Caspian Sea invader Mnemiopsis leidyi (A. Agassis, 1865) on marine and anadromous fish species. There has been given the analysis of unfavourable effect of invader Mnemiopsis leidyi (A. Agassis, 1865) on the abundance of marine, anadromous, semi-anadromous fishes and Caspian seal. There have been considered mechanisms, sequence and degree of impact of ctenophoran on ichthyophauna and marine mammals via a nutritive base. It has been stated that mnemiopsis distribution corresponds to seasonal distribution of zooplankton and meroplankton, whereas ctenoforan being an organism with aggressive "r-strategy" of development influences ichthyophauna both directly (eating pelagic roe and larvae of sea fish) and indirectly (via nutritive base). Drastic reduction of catches of the Caspian sprat, in particular anchovy sprat and big-eyed sprat, is stipulated by nutritional competence between these fish species and ctenoforan Mnemiopsis leidyi. In turn, decrease in number of the Caspian sprat resulted in change of the nutrient budget of the sturgeon (Russian sturgeon, stellate sturgeon, beluga) and in decrease of their number and commercial stocks. There have been offered the solutions to the ecological problem and measures to restore sturgeon stocks. Results of the research can be used in forecasting commercial fish species stocks in the Caspian Sea and in determining the damage from annual invasions of Mnemiopsis ( Memiopsis leidyi (A. Agassis, 1865)) in the northern part of the Caspian Sea.

INFLUENCE OF THE ENVIRONMENTAL FACTORS ON SHEATFISH FISHING IN THE VOLGA-CASPIAN AND THE NORTH-CASPIAN FISHERY SUBAREAS

2018 ◽  
pp. 49-58
Author(s):  
Gennadij Grigor'evich Kolosyuk ◽  
Sergey Yurievich Nikiforov
Keyword(s):  
Environmental Factors ◽  
Sea Level ◽  
Fish Species ◽  
Abiotic Factors ◽  
The Caspian Sea ◽  
Delta Front ◽  
Volga River ◽  
Commercial Fish ◽  
Silurus Glanis ◽  
The North

Delta and delta front of the Volga river are the main fishing areas in the Astrakhan region, which provide high fish capacity. At the same time, productiveness of fishing in these areas is extremely unstable because they are effected by numerous environmental factors. The essential factor is changing the level of the Caspian Sea, which is directly related to hydraulicity of the Volga watershed. Sea-level change results in changing the area of shallow water zone and coast line, which strongly impacts on a previous biotope. Besides changing the sea level and the volume of fresh-water flowing, water bio-resources are influenced by the volume of spring flood, terms of the flood beginning and thermal regime in the region. Interference of all these factors impacts on stock forming and on fishing of all fish species caught in this region. But this interference of different fish groups (semi-anadromous, river, non-migratory) is ambiguous, which is related with their biology. The purpose of the research is to define the influence of these factors on fishing one of the most important commercial fish species - sheatfish ( Silurus glanis ). The analysis of the available materials has shown that sheatfish catches in a great degree depend on some abiotic factors. Thus, raising the sea level leads to the decrease of sheatfish catches, and increasing of water mass during the flooding period in the Volga river results in lowering the total catch. Later beginning of the flood period improves the effectiveness of fishing, as well as early warning-up of water.

Trace element accumulation in fishes collected from coastal waters of the Caspian Sea

2005 ◽  
Vol 51 (8-12) ◽  
pp. 882-888 ◽  
Author(s):  
Yasumi Anan ◽  
Takashi Kunito ◽  
Shinsuke Tanabe ◽  
Igor Mitrofanov ◽  
David G. Aubrey
Keyword(s):  
Trace Element ◽  
Coastal Waters ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Element Accumulation ◽  
Trace Element Accumulation

scholarly journals Evaluation of Trace Metal Levels in Tissues of Two Commercial Fish Species in Kapar and Mersing Coastal Waters, Peninsular Malaysia

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Fathi Alhashmi Bashir ◽  
Mohammad Shuhaimi-Othman ◽  
A. G. Mazlan
Keyword(s):  
Trace Metal ◽  
Fish Species ◽  
Coastal Waters ◽  
Positive Association ◽  
Peninsular Malaysia ◽  
International Standards ◽  
Metal Concentrations ◽  
Commercial Fish ◽  
Metal Levels ◽  
The Relationship

This study is focused on evaluating the trace metal levels in water and tissues of two commercial fish species Arius thalassinus and Pennahia anea that were collected from Kapar and Mersing coastal waters. The concentrations of Fe, Zn, Al, As, Cd and Pb in these coastal waters and muscle, liver and gills tissues of the fishes were quantified. The relationship among the metal concentrations and the height and weight of the two species were also examined. Generally, the iron has the highest concentrations in both water and the fish species. However, Cd in both coastal waters showed high levels exceeding the international standards. The metal level concentration in the sample fishes are in the descending order livers > gills > muscles. A positive association between the trace metal concentrations and weight and length of the sample fishes was investigated. Fortunately the level of these metal concentrations in fish has not exceeded the permitted level of Malaysian and international standards.

scholarly journals MICROALGAE FROM THE COASTAL WATERS OF TYULENY ISLAND IN THE CASPIAN SEA

2019 ◽  
Vol 14 (2) ◽  
pp. 120-131
Author(s):  
R. M. Barkhalov ◽  
A. A. Abdurakhmanova ◽  
F. Sh. Amaeva
Keyword(s):  
Coastal Waters ◽  
Caspian Sea ◽  
Biomass Concentration ◽  
Water Area ◽  
Trophic Chain ◽  
The Caspian Sea ◽  
Standard Procedures ◽  
Water Surface Layer ◽  
Rich Flora ◽  
Positive Effect

Aim. In this work, we set out to study the composition of a phytoplankton community in an important fishery area, the coastal water area of Tyuleny Island in the Caspian Sea.Methods. We present the results of seasonal observations (2016) on the state of phytoplankton in the coastal waters of Tyuleny Island in the Caspian Sea. In total, 120 phytoplankton samples were collected at four stations from the water surface layer (May–October) using the Nansen bottle and subsequent fixation by Lugolʹs solution. Sedimentation and concentration were carried out using standard procedures. The samples were processed in the Nageotte chamber with a volume of 0.1 ml under a light microscope.Results. According to the research results (2016), 103 species and varieties of microalgae were found in the phytoplankton samples collected from the water area of Tyuleny Island. The microalgae were represented by four divisions: Bacillariophyta – 49 species, Cyano‐ phyta – 24 species, Chlorophyta – 23 species and Pyrrophyta – 7 species. The greatest species diversity of phytoplankton in the studied water area was noted during the autumn period (61 spe‐ cies). In general, phytoplankton was found to be distributed homogeneously throughout the coastal area of the island, with the biomass concentration not reaching 1 g/m3.Conclusion. In 2016, favorable hydrological and hydrochemical conditions for the development of microalgae were observed. The desalinated water around Tyuleny Island, which is well warmed in the summer and does not freeze in the winter, contributed to the development of rich flora. Although bi‐ omass values were not high due to the prevalence of small‐celled microalgae in phytoplankton, in general, it should have a positive effect on the development of subsequent links in a trophic chain, as well as promote an increase in the productivity of waters of the Northern Caspian Sea. 

scholarly journals The effects of stock enhancement of pikeperch (Sander lucioperca) in Iranian coastal waters of the Caspian Sea

2007 ◽  
Vol 64 (5) ◽  
pp. 973-980 ◽  
Author(s):  
Shahram Abdolmalaki ◽  
Iwona Psuty
Keyword(s):  
Coastal Waters ◽  
Caspian Sea ◽  
Stock Enhancement ◽  
Early Years ◽  
Predatory Fish ◽  
Market Demand ◽  
Sander Lucioperca ◽  
The Caspian Sea ◽  
Artificial Culture ◽  
Abundant Population

Abstract Abdolmalaki, S., and Psuty, I. 2007. The effects of stock enhancement of pikeperch (Sander lucioperca) in Iranian coastal waters of the Caspian Sea. – ICES Journal of Marine Science, 64: 973–980. Annual landings of pikeperch (Sander lucioperca) in Iranian coastal waters of the Caspian Sea in the early years of its exploitation, the late 1920s and early 1930s, reached some 3000 t. However, after 1935, catches declined drastically through overfishing, declining sea level, and the destruction of spawning grounds in the Anzali Lagoon. In 1990, Iran initiated a programme of artificial culture to enhance the local stock. The aim of the programme was and still is to restore the formerly abundant population of this predatory fish and to increase the profitability of the beach-seine fisheries of fishers who had stopped deploying gillnets, which pose a threat to the valuable species of sturgeon in the Caspian. Analysis of the age composition of pikeperch catches indicates that the use of beach-seines does not prevent overfishing of young pikeperch released as fingerlings in the same calendar year in which the fishing season started. No undersized fish are discarded back into the sea, because there is market demand for even the smallest fish, and a lack of communication exists between the programme beneficiaries and the management and research units. Some 15 years after it was initiated, the effectiveness of stock enhancement at a level of 4–6million fry per year remains uncertain.

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