Age determination with some bony structures and length-frequency method of sprat (Sprattus sprattus L., 1758) in the Black Sea

2008 ◽  
Author(s):  
Nazmi Polat
Keyword(s):  
Black Sea ◽  
Age Determination ◽  
The Black Sea ◽  
Length Frequency ◽  
Frequency Method ◽  
Sprattus Sprattus

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.

Fish Stock Indicators as Measure for Sustainability

2015 ◽  
pp. 118-182 ◽  
Author(s):  
Violin S. Raykov ◽  
Ivelina Zlateva
Keyword(s):  
Black Sea ◽  
Fishery Management ◽  
Management Strategies ◽  
Age Determination ◽  
Reproductive Potential ◽  
Local Environment ◽  
Point Of View ◽  
The Black Sea ◽  
Fish Stock ◽  
Mortality Estimation

Particular species may be good indicators of specific environmental factors in their local environment. It was found that one of the main objectives for effective and sustainable management of the fish stocks is to make regular annual assessment of the parental stock biomass, length and weight growth, age determination, mortality estimation and reproductive potential estimation. The Black Sea sprat (Sprattus sprattus L.) is a key species in the Black Sea ecosystem. Small pelagic forage fish and especially local one with shared stocks are very important from ecological (key trophic level) and commercial (intensively exploited) point of view. Fishery management strategies must ensure that fishing mortality will not exceed that which corresponds to MSY, and that the biomass will not fall below a predefined threshold. The goal of the chapter is to define the main objectives and measures for sustainable sprat exploitation in order to be in favour of decision makers and fishery managers.

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

Determination of some population parameters of the veined rapa whelk (Rapana venosa) in the Central Black Sea

2014 ◽  
Vol 95 (1) ◽  
pp. 123-129
Author(s):  
Naciye Erdoğan Sağlam ◽  
Cemil Sağlam ◽  
Yeşim Demir Sağlam
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
The Black Sea ◽  
Population Parameters ◽  
Length Frequency ◽  
Alternative Product ◽  
Mediterranean Mussel ◽  
Length Frequency Data ◽  
Rapa Whelk

The veined rapa whelk is one of the most important invasive species in the Black Sea ecosystem since the 1940s. Following its introduction to the Black Sea, it destroyed most of the bivalve populations, mainly the Mediterranean mussel and oysters. However, the veined rapa whelk has commercial importance for the Black Sea fisheries as an alternative product. In this study, we aimed to determine some population parameters of the veined rapa whelk based on indirect ageing through length–frequency data by using the Bhattacharya method. We collected 1704 specimens by dredging along the coasts of Samsun Province in the Central Black Sea in 2011 from June to November. The age of the population varied from 0 to 6. Von Bertalanffy growth parameters were estimated as L∞ = 112.35 mm, k = 0.310, t0 = −0.486 and W∞ = 243.94 g. Mean length and weight, length–weight relationship, mortality and exploitation rates were derived as L = 56.80 ± 0.36 mm, W = 45.67 ± 0.89 g, W = 0.0006 L2.719, Z = 0.96, M = 0.57, F = 0.39 and E = 0.40, respectively.

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.

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 Local overfishing of the Black Sea sprat (Sprattus sprattus: Clupeidae, Pisces) and intraspecies differentiation

2018 ◽  
Vol 3 (1) ◽  
pp. 35-45
Author(s):  
G. V. Zuyev ◽  
V. A. Bondarev ◽  
Iu. V. Samotoi
Keyword(s):  
Black Sea ◽  
Average Length ◽  
The State ◽  
The Black Sea ◽  
Western Region ◽  
Commercial Catch ◽  
Sprattus Sprattus ◽  
The Western Region ◽  
Commercial Stock

The Black Sea sprat (Sprattus sprattus) is known to be one of the most numerous fish species in the Azov – Black Sea basin. It is an object of fishing in all the Black Sea countries, its catch reaches 100 thousand tons. Therefore, the task to monitor the state of the sprat population and identify the risk factors under existing conditions of increasing fishing intensity and climate change is of great importance. The subject of the study is to assess the impact of fishing on the state of the Black Sea sprat population and estimate the prospects of further exploitation of its commercial stock. The article is based on the results of our research and the annual reports of the European Commission’s Scientific, Technical and Economic Committee for Fisheries (STECF). The catch of sprat in both regions was carried out with mid-water trawls, in the shelf zone in the near-bottom layer of water. In all calculations, the standard length (SL) in cm was measured. Long-term (2003–2013) dynamics of integrated characteristics of the size-age structure of sprat population (average length and average age of sprat) and also sprat catch from two geographically similar in climatic conditions regions, the Crimean region and the Western region (the shelf of Bulgaria and Romania), was investigated. Interregional differences in characteristics of the size-age population structure and fishing conditions were identified. In the Crimean region, the average length of sprat varied from 5.57 to 6.85 cm, the average was 6.43 cm. The interannual amplitude of the SL fluctuations was near 20 %. The average sprat age varied from 0.9 to 1.57 year, the average fish age in the population was 1.4 year. The interannual amplitude of sprat age fluctuations was more than 57 %. Negative trends of the average sprat length and its average age have been determined, indicating deterioration of the population state as a whole and of its commercial quality, in particular. The annual commercial catch of sprat varied from 11.4 to 24.78 thousand tons, the average annual catch was 16.09 thousand tons. The interannual amplitude of the catch fluctuations was more than 2.2 time. A close negative correlation between high catches and low average lengths and, as well as low average sprat age in the population for one year forward, was found (r = -0.81, p < 0.01 and r = -0.82, p < 0.01). In the Western region, unlike the Crimean, the sprat was longer, the average length of fish varied from 7.24 to 7.62 cm, average was 7.46 cm. Interannual amplitude of fluctuations less than 5 % indicated a sustainable state of the population. The annual commercial catch of sprat varied from 2.77 to 4.64 thousand tons, with the fishing effort upon the population did not exceed the maximum allowable level. The average annual catch was 3.75 thousand tons, which was 4.3 time lower than that in the Crimean region. There was no significant correlation between the catch and the average length of sprat (r = -0.27, p > 0.15). Local overfishing of sprat in the Crimean region together with long-term progressive deterioration of the sprat population state suggested division of total commercial fish stock into separate commercial unit stocks. This contradicts the concept of total commercial stock (a single population) of the Black Sea sprat. This conclusion is preliminary and further investigations in this area are to be made.

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