Estimation of the age, size and sex composition and growth parameters of anchovy, Engraulis encrasicolus (L.) in the Black Sea

1989 ◽  
Vol 7 (3) ◽  
pp. 241-247 ◽  
Author(s):  
I. Erkoyuncu ◽  
E. Ozdamar
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
The Black Sea ◽  
Sex Composition ◽  
Engraulis Encrasicolus ◽  
Size And Sex Composition

scholarly journals Long-term dynamic of reproductive performance of European anchovy Engraulis encrasicolus Linnaeus, 1758 and its connection with temperature

2017 ◽  
Vol 2 (2) ◽  
pp. 3-19
Author(s):  
G. V. Zuev ◽  
T. N. Klimova
Keyword(s):  
Water Temperature ◽  
Black Sea ◽  
Relative Abundance ◽  
The Black Sea ◽  
Western Coast ◽  
European Anchovy ◽  
Engraulis Encrasicolus ◽  
European Anchovy Engraulis Encrasicolus ◽  
Calendar Dates

European anchovy (Engraulis encrasicolus Linnaeus, 1758) is one of the most numerous species of fish in the Azov-Black Sea basin. It is the main commercial fishery object, its share being about 80 %. Assessment of the functional state of the anchovy population and its dynamics in conditions of the climatic warming was one of the topical tasks in contemporary research. The paper is devoted to the study of a long-term dynamic of anchovy population: reproductive parameters and its relation with water temperature for the purpose of potential prediction. The results of our own investigations made in 2000–2015 in the area bordering the south-western coast of Crimean peninsula (Sevastopol–Balaklava region) have been considered in the paper. The eggs were collected with Bogorov – Rass net (BR-80/113) from the layer of 0–10 m. Adult specimen were caught with pound seines. 702 ichthyoplankton samples and 941 mature anchovy females (gonad maturation stage V, VI–IV and VI–V) were analyzed. Calendar dates and duration of spawning season, intensity and efficiency of spawning, intraspecific composition of mature anchovy females were researched. Calendar dates of anchovy spawning beginning near the south-western coast of Crimea in 2000–2014 varied from the 2ⁿᵈ decade of May (early spawning) to the 3ʳᵈ decade of June (late spawning); finishing dates – from the 3ʳᵈ decade of August to the 3ʳᵈ decade of September. Total reproductive period duration was 8–14 weeks, average – 11 weeks. In long-term plan the time shift for earlier calendar dates was determined at the start of the spawning. Maximum peak of spawning intensity in 2012–2013 varied from 33.6 to 78.7 % (average 51.2 %). Peak of population spawning was in July – August, its repeatability in July – 25 and in August 66.7 %. The peak spawning shift to the earlier time was determined in perennial plan: in 2000–2005 years peak spawning periodicity amounts in August to 100 %; in 2007–2013 – only 50 %. Absolute number of eggs (spawning efficiency) change from 1.6 to 29.9 specimen·m-2 in 2000–2014 years (average 10.3 specimen·m-2). Low, average and high yielding years with number of eggs less than 10, 10–20 and more than 20.0 specimen·m-2 were determined. The average spawning efficiency was: 5.1, 14.5 and 25.0 specimen·m-2 respectively. Spawning efficiency in high-yielding years exceeded 1.7 and 4.9 times the efficiency of low and average-yielding years. In long-term plan the positive efficiency spawning trend was determined. In 2000–2001 the intraspecific structure reconstruction of anchovy took place, followed by redistribution of numerical relation in composition of spawning part of the Azov and the Black Sea subspecies in favor of the last one. In 2000–2004 relative abundance of Black Sea anchovy amounted 33.3 %, in 2005–2011 years – 76.7 %. Simultaneously a considerable catch growth was registered. Сorrelation coefficient of the Black Sea anchovy’s relative abundance and catch was 0.92. Calendar time of spawning beginning, its intensity and efficiency are closely connected with the water temperature. Lower temperature limit for mass spawning was 17.5 °С. The region of “maximum favorable spawning temperature” lays in the range of 23 °C and warmer. Nearly 2/3 of population reproductive potential is realized within this temperature range.

scholarly journals Population Dynamics of Horse Mackerel (Trachurus Mediterraneus Ponticus) in the Bulgarian Black Sea Coast

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Maria Yankova
Keyword(s):  
Black Sea ◽  
Growth Parameters ◽  
Total Mortality ◽  
Growth Function ◽  
Horse Mackerel ◽  
The Black Sea ◽  
Growth Coefficient ◽  
Von Bertalanffy Growth Function ◽  
Black Sea Coast ◽  
Commercially Important

The horse mackerel Trachurus mediterraneus is a commercially important pelagic fish species in the Black Sea fishery. The present investigation was carried out between May and December 2010 along the Bulgarian coast of the Black Sea. Population parameters of horse mackerel from the trawl and fishing nets catches were estimated from length frequency data, by using ELEFAN-I computer program. The ELEFAN-I analysis gave the following Von Bertalanffy Growth Function (VBGF) parameters: the asymptotic length  cm, growth coefficient value was , and the hypothetical age at which length is zero was . Based on these growth parameters, the total mortality coefficient () during the study period was estimated to be 2.99. The estimated value for natural mortality () was 1.08; hence, the fishing mortality coefficient () was 1.91. The estimated value for the exploitation rate () using the length converted catch curve was 0.64. The estimated sizes of T. mediterraneus at 25, 50, and 75 percent probabilities of capture were 16.80 cm, 18.72 cm, and 20.64 cm, respectively.

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.

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