A stock differentiation study of the sprat (Sprattus sprattus phalericus Risso) off the southern coast of the Black Sea

1994 ◽  
Vol 19 (3-4) ◽  
pp. 363-378 ◽  
Author(s):  
Dursun Avsar
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Southern Coast ◽  
Sprattus Sprattus ◽  
Stock Differentiation

scholarly journals Modern state of the reproductive potential of Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) (Pisces: Clupeidae) in Crimean region and conditions for its formation

2019 ◽  
Vol 4 (4) ◽  
pp. 3-14
Author(s):  
G. V. Zuyev
Keyword(s):  
Black Sea ◽  
Average Length ◽  
Reproductive Potential ◽  
Danube River ◽  
The Black Sea ◽  
Total Catch ◽  
Sprattus Sprattus ◽  
The Absolute ◽  
Individual Fecundity

Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) is one of the abundant species of fish in the Sea of Azov – Black Sea basin. Due to its large number sprat plays an extremely important role in the ecosystem of the sea, being an intermediate link between zooplankton and representatives of the highest trophic level – large predatory fish, dolphins, and birds. At the same time sprat is one of the important commercial fish in all the Black Sea countries, steadily being on the second place of catch volume in recent decades (after anchovy). The total catch reaches 100 thousand tons. Turkey and Ukraine are the main producing countries. Monitoring and forecast of biological state of sprat population with rising fishing intensity and climate changes are urgent tasks. The research subject of this article is the long-term (2000–2016) dynamics of biological (qualitative) parameters determining the population fecundity of Black Sea sprat in Crimean region, the current state of reproductive potential, and the conditions for its formation. The article is based on the results of own research. Parameters determining the population fecundity – the length-age structure of the spawning part population, the absolute individual fecundity, and the sex structure population (ratio between females and males) – were studied. In the long-term plan (in 2011–2016 compared with 2000–2004) the average length of spawning females decreased by 1.22 times (from 7.36 to 6.03 cm). It was accompanied by a decrease in the absolute individual fecundity by 2.39 times (from 13 625 to 5690 eggs). The numerical ratio between females and males decreased by 1.23 times (from 1.95 to 1.59). Simultaneously the sprat stock in the northern part of the Black Sea was reduced by more than 2.5 times (from > 500 thousand tons to < 200 thousand tons). As a result, the population fecundity of sprat in Crimean region decreased by more than 7 times (2.39 × 1.23 × 2.5). The conditions of sprat fishing in the northern part of the Black Sea (from the mouth of the Danube River to the Kerch Strait) were studied. They showed 2-fold decrease (from 251.9 thousand tons in 2000–2004 to 129.1 thousand tons in 2011–2016) in the total catch and more than 2.3-fold decrease (from 50.4 to 21.4 thousand tons) in average annual catch in this region. On the contrary, in the Crimean shelf the total catch at that time increased by 1.2 times (from 76.9 to 92.2 thousand tons), and its average annual value remained constant (15.4 thousand tons). While reducing the stock by 2.5 times, this means that the fishing pressure on the Crimean population increased 2.5 times. This fact suggests considering the factor of fishing as the main cause of its degradation. Validity of this version is confirmed by the fact of conjugacy (inverse connection) of interannual fluctuations between the catch and the length-age parameters of sprat in Crimean region in 2003–2013 previously found: catches over 15–16 thousand tons were accompanied by a next year decrease in the fish average length. Regulation of fishing is a necessary condition for preventing further degradation, for restoring and maintaining sustainable state of sprat population in Crimean region and its reproductive potential. The negative impact of natural (climatic and trophic) factors on the state of the population should be recognized as a secondary one. Local overfishing indicates indirectly the structuring of the commercial stock of Black Sea sprat, its division into a number of geographical aggregations (stock units), i. e. the presence of intraspecific differentiation.

scholarly journals Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part III: Mollusca (Gastropoda)

2018 ◽  
Vol 3 (1) ◽  
pp. 23-34
Author(s):  
I. P. Bondarev ◽  
N. K. Revkov
Keyword(s):  
Black Sea ◽  
Biological Diversity ◽  
Solid Substrate ◽  
Taxonomic Composition ◽  
Egg Laying ◽  
The Black Sea ◽  
Southern Coast ◽  
Gastropod Species ◽  
Rapana Venosa ◽  
Rapa Whelk

This work is a continuation of a series of descriptions of the taxonomic composition of the consort community of Rapana venosa. The shell of the large invasive gastropod R. venosa, which occupies the ecological niche of the terminal predator in benthic community, is simultaneously an attractive substrate for various hydrobionts – fouling and associated mobile forms, one of which is small gastropod mollusks. The latter are poorly explored and accounted for in the R. venosa consortium. The study of this group of hydrobionts in the composition of epibionts of rapana was carried out on the material obtained in 7 regions of the northern part of the Black Sea: 1 – Mamaya, coast of Romania; 2 – NW Crimean coast, Tarkhankut area; 3 – SW coast of Crimea, Sevastopol; 4 – Southern coast of Crimea, Alupka; 5 – Southern coast of Crimea, Yalta – Alushta; 6 – SE coast of Crimea, Karadag; 7 – Kerch Strait. Sampling of rapa-whelk in the coastal zone up to a depth of 15 m was carried out using light water diving equipment, in the deeper zone (up to 40 m), the “Ocean-50” bottom grabber was used from the board of the RV “Professor Vodyanitsky”. Gastropods as consorts of rapa-whelk were found predominantly in reg. 3, where in the summer – autumn season 2015–2017 the most detailed works were carried out and about 90 % of the material was sampled (1100 of 1216 R. venosa specimens). It was found that gastropods in the consortia of rapana were represented by 14 species of 9 genera of 6 families, 7 species of them with egg laying. The gastropods were observed in the consortium of R. venosa mainly in the epiphyton community of algal fouling of the shell, where the mollusc-consorts can form significant clusters – more than 60 individuals. Directly on the shell of the rapa-whelk, the gastropods were found singly or in small groups – from 2–5 to 10 individuals. The most numerous and often occurring (up to 25 %) gastropod species in the consortium of R. venosa was Bittium reticulatum (Cerithiidae). Less numerous were Tricolia pullus (Phasianellidae) (5–10 %, in Kazachya Bay – up to 25 %) and Rissoa splendida (Rissoidae) (the occurrence on the average was about 10 %). The remaining species were observed singly. The highest species diversity and abundance of gastropods were recorded at the depth of 4–10 m in the consortium of loose soils R. venosa ecomorph – 14 species; on the rocky ecomorph of rapa-whelk inhabiting the zone of more intensive hydrodynamics – only 2 species. Our research demonstrates that the ecological role of the invasive species of the Black Sea fauna, R. venosa, is not limited to be a predation. In particular, it contributes to reproduction, development and resettlement of other gastropod species. In the biotope of loose soils, where the there is a deficit of the solid substrate necessary for reproduction of many species of hydrobionts, including gastropods, R. venosa is “oasis” increasing the biological diversity of the benthos as a whole.

scholarly journals Winter jellyfish macroplankton off the coastal of Crimea

2016 ◽  
Vol 1 (4) ◽  
pp. 22-29
Author(s):  
S. M. Ignatyev ◽  
V. V. Gubanov ◽  
N. A. Datsyk
Keyword(s):  
Black Sea ◽  
Size Range ◽  
Size Structure ◽  
The Black Sea ◽  
Winter Period ◽  
Small Range ◽  
Total Biomass ◽  
Southern Coast ◽  
South Eastern ◽  
Azov Sea

Predatory macroplankton of jellyfish species is an important component of the pelagic ecosystem. It is capable of mass development, and may influence pelagic communities. Surveillance monitoring of jellyfish populations can detect the seasonal and long-term trends of their variability and assess the role of jellyfish in the trophic structure of the pelagic zone. Monitoring of plankton community (jellyfish macroplankton) off the coastal of Crimea from the Cape Tarkhankut to the Kerch coast (including the Azov Sea) in winter period is presented. 22 comprehensive oceanographic stations from Cape Tarkhankut to the Kerch Strait and in Azov Sea at the depths of up to 100 m were made. We used a Bogorov — Russ plankton net (entrance area is 0.5 square meters) for collecting plankton in the upper 100-m water layer. Jellyfish were measured immediately, we used a standard method of measuring and calculated the mass of the individual instances by the formulas. The biomass is calculated as the product of the abundance and the average wet weight of organisms in the population. Abundance and biomass macroplankton were counted per square meter of water surface or per the volume of filtered water. The species composition of jellyfish macroplankton was represented by 1 species of jellyfish and 3 species of ctenophores. Aurelia aurita dominated in biomass (98 % of the total biomass of gelatinous macroplankton)  everywhere; Pleurobrachia and Aurelia dominated in abundance (67 and 25 % respectively). The share of both species of ctenophores-invaders did not exceed 8 %. The average relative abundance of jellyfish along the coast of Crimea was fluctuated between 9 and 43 %, comb jellies — from 32 to 77 %. Quantitative distribution of gelatinous macroplankton was non-uniform — from complete absence to 83.3 g·m-3 (average of 12.6 g·m-3). The highest biomass was registered in the area of Sevastopol and Eupatoria, the minimum — off the southern coast of Crimea. Jellyfish were noted at almost all stations. Their biomass reached a value of 18 g·m-3. Distribution of jellyfish is characterized by marked heterogeneity with higher values of abundance and biomass in the area of the southern coast of Crimea and lower — in the stations in the western part of the Black Sea. Aurelia was presented with large dome diameter of 21–220 mm (average diameter — 93 mm). The bulk of the population was accounted for last year’s individuals generation. Biomass of the ctenophore M. leidyi varied from 86 to 4788 mg·m-3 (average of 1595 mg·m-3). The structure of its population was represented by wide size range of animals — 10–65 mm, while the share of larger animals of 60–100 % was observed in the western and south-eastern parts of the Black Sea. On the southern coast of Crimea 45 % of population of ctenophore were animals of 15–25 mm. Biomass of the ctenophore B. ovata was within 34.8–1316.6 mg·m-3 (average of 371.4 mg·m-3). Its abundance varied within a small range, except the area of Feodosia stations, where the maximum value was observed (it was more than 1 g·m-3). B. ovata population consisted of individuals of 20–40 mm long, while it formed the basis of immature specimens of 20–30 mm (50–70 % of the total). In Kerch area their share has reached 100 %. There were hibernating animals of last year’s generation. The coldwater ctenophore Pleurobrachia pileus was present almost everywhere, with biomass from 0.1 to 6.0 mg·m-3. Maximum values of abundance were observed in Alushta region. The stations of Crimean southern coast were characterized by intermediate, relatively flat values. South-eastern and western parts of the Black Sea were marked by similar values of abundance and biomass. In all studied regions, the prevailing size group in the structure of P. pileus populations were individuals with a  diameter of 10 mm. In the deep-sea area of the southern part of Crimea population was represented in the larger size range, and the proportion of animals ranging in size from 11 to 20 mm was low (5 %). In general, “winter” composition, size structure and abundance of jellyfish off the coast of the Crimea are the same of indicators in the coastal waters of Sevastopol. But the results show the existence of certain differences in the structure and quantitative development of jellyfish macroplankton in southern and  western coasts of Crimea.

Effect of Certain Abiotic and Biotic Factors on Spawning of the European Sprat Sprattus sprattus (Linnaeus, 1758) in the Black Sea in November 2016–2017

Oceanology ◽  
2021 ◽  
Vol 61 (1) ◽  
pp. 58-68
Author(s):  
T. N. Klimova ◽  
I. V. Vdodovich ◽  
B. E. Anninsky ◽  
A. A. Subbotin ◽  
P. S. Podrezova ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Biotic Factors ◽  
Sprattus Sprattus ◽  
Abiotic And Biotic Factors

scholarly journals Pontus, Bithynia and the Bosporus

1918 ◽  
Vol 22 ◽  
pp. 1-22 ◽  
Author(s):  
M. Rostovtsef
Keyword(s):  
Black Sea ◽  
Economic Conditions ◽  
The Black Sea ◽  
Small Displacement ◽  
Southern Coast ◽  
Natural Conditions ◽  
Naked Eye ◽  
The Crimea ◽  
Great Prosperity

Everyone who has the slightest acquaintance with the Crimea at the present time, and especially with the economic conditions which prevail there, is thoroughly aware of its intimate connexion, both economic and social, with the southern coast of the Black Sea—with Samsun, Eregli, Sinope, Kerasund, Trebizond and other towns. Great masses of workmen from these parts flood the cities of the Crimea. Practically all shipments by sea in vessels of small displacement are carried out by the owners of feluccas, who hail from the municipal centres of ancient Pontus and from the neighbouring sea-towns of what was once Bithynia. A glance at the map is sufficient to show that there is no casual connexion here; the close interconnexion between the shores of the Crimea and the southern coast of the Black Sea, which is almost visible with the naked eye from the southernmost point of the Crimea, has been brought about by the natural conditions of the locality. The decline in the prosperity of the southern Turkish coast of the Black Sea and the great prosperity of the Crimea in the years immediately preceding the war were the chief reasons why the Crimea played the part of employer, and the sea towns of the southern coast the part of supplier of labour. They provided as well the necessary tonnage for coastwise shipping, mostly in the shape of small sailing vessels. Such could not always be the case, nor indeed have such conditions continuously prevailed, although, generally speaking, similar relations must needs be established quite independent of the fortune assigned by history to the districts with which we are now dealing.

Distribution of Sprattus Sprattus Phalericus (Risso, 1827) and Zooplankton Near the Black Sea Redoxcline

2021 ◽  
Author(s):  
Victor Melnikov ◽  
Falk Pollehne ◽  
Natalia Minkina ◽  
Lidia Melnik
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Sprattus Sprattus

scholarly journals Sex Differences and Sex Identification in the Small-Scaled Scorpionfish, Scorpaena Porcus (Scorpaenidae, Scorpaeniformes)

2016 ◽  
Vol 50 (4) ◽  
pp. 355-362
Author(s):  
V. N. Peskov ◽  
L. G. Manilo
Keyword(s):  
Sex Differences ◽  
Black Sea ◽  
Coastal Waters ◽  
Morphological Characters ◽  
Sex Identification ◽  
The Body ◽  
The Black Sea ◽  
Southern Coast ◽  
The Absolute ◽  
Scorpaena Porcus

Abstract Sex differences and the ability to determine the sex of Scorpaena porcus (Linnaeus, 1758) on morphological characters were studied in the population inhabiting coastal waters of the Black Sea near the southern coast of Crimea. These differences were revealed in size (females are larger than males) and in proportions of the body. It is found that variation of the absolute and relative values in plastic characters is higher in females compared with males. It is shown that in 92 % of individuals belonging to S. porcus we can determine the sex using morphological characters with a probability of 99.9-100 %.

scholarly journals Spring diet and feeding strategy of the European sprat Sprattus sprattus (L., 1758) from the Black Sea coast of Turkey

2015 ◽  
Vol 3 (9) ◽  
pp. 697
Author(s):  
Bahar Bayhan ◽  
Tuncay Murat Sever
Keyword(s):  
Black Sea ◽  
Diet Composition ◽  
Feeding Strategy ◽  
Diet Analysis ◽  
The Black Sea ◽  
Frequency Of Occurrence ◽  
Trophic Specialization ◽  
Sprattus Sprattus ◽  
Black Sea Coast ◽  
Sea Coast

This study aims to identify the spring diet composition and feeding strategy of the European sprat, Sprattus sprattus. Diet composition of European sprat was investigated for the first time in the central Black Sea coast of Turkey. Examined of the 115 specimens (6 - 9.1 cm total length) of stomach, 12 (10.4%) had emty. Diet analysis was described based on gravimetric percentages (W%), frequency of abundance (N%), frequency of occurrence (%F) and relative importance index (IRI%). Feeding strategy was analyzed and graphically (Costello) represented, considering the frequency of abundance (N%) and frequency of occurrence (%F) indexes and grouping prey into higher taxonomic categories. Twenty species were identified, belonging to four prey groups: Polychaeta, Crustacea, Mollusca and Chaetognatha. Finally copepods proved to be the most important food item considering the above-cited indexes. All other prey taxa were identified as accidental preys. At least seven copepod species were identified, where Calanus euxinus appeared all round with %IRI≥50. Also results of feeding strategy analyses revealed a trophic specialization toward a single prey.

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