BIOLOGICAL CHARACTERISTICS OF THE SPAWNING STOCK OF PONTIC SHAD ALOSA IMMACULATA (BENNET, 1835) IN THE UKRAINIAN PART OF THE LOWER DANUBE
DOI:
https://doi.org/10.47143/1684-1557/2025.1-2.2Keywords:
pontic shad, Danube, population structure, growth parameters, natural mortality, exploitation rateAbstract
The aim of the study was to clarify the biological parameters of the spawning stock of the of pontic shad Alosa immaculata (Bennet, 1835) in the Ukrainian part of the lower Danube. Materials were collected in 2017–2024 in the area of the Kiliya estuary below 24 km and Solomon’s Arm (3–1 km). We examined 112 catches from shad driftnets with a mesh size of 30–32 mm. The key population parameters were determined: sex, age, size and weight structure, fatness coefficients, growth rates, natural and fishing mortality. The ratio of males to females in the samples was 1 : 2.36 (p < 0.05), with a predominance of females (68.5%). The age composition is stable, with the dominance of 3–4-year-old individuals (85.3%), while older age groups (6–7 years) are represented exclusively by females. The average total length of shad ranged from 29.3 to 32.13 cm (mean 30.6 ± 2.6 cm), females were larger than males (p < 0.05). Fulton’s fatness index ranged from 1.15–1.36 (mean 1.23 ± 0.16), indicating stable feeding conditions in the Black Sea. The Bertalanffy growth equation was estimated as L∞ = 41.74 cm, k = 0.322, t0 = –0.51, with faster growth of females compared to males (B = 2.83, p < 0.05), which corresponds to a negative allometric growth model. Mortality coefficients: total (Z) – 1.72, natural (M) – 0.83 (0.51 for 3–4+ years), fishing (F) – 0.89. The exploitation rate (E = 0.517) is close to the optimal one (E = 0.5), indicating a relatively stable level of population exploitation. Changes in the sex and age structure are partly due to the selectivity of the fishery, in particular, an increase in the mesh size of the nets to 32 mm, which reduced the proportion of smaller males. The data obtained can be used to predict population dynamics and develop science-based approaches to fisheries management, contributing to the rational use and conservation of the species.
References
1. Бушуев С.Г. Современные данные о состоянии нерестового стада дунайской сельди Alosa kessleri pontica (Eichw.) в 1994–1995 годах. Труды ЮгНИРО. 1996. Т. 42. С. 254–258.
2. Бушуев С.Г. Перспективы промысла дунайской сельди в связи с возобновлением глубоководного судового хода «Дунай – Черное море». Рыбное хозяйство Украины. 2006. № 1–2. С. 18–24.
3. Владимиров В.И. Основные задачи и итоги изучения дунайской сельди. Труды Института гидробиологии АН УССР. Выпуск: Дунайская сельдь и биологические основы ее промысла. 1953а. № 28. С. 5–8.
4. Владимиров В.И. Биология личинок дунайской сельди и их выживаемость. Труды Института гидробиологии АН УССР. Выпуск: Дунайская сельдь и биологические основы ее промысла. 1953b. № 28. С. 30–66.
5. Ляшенко А.Ф. Биология молоди дунайской сельди и ее количественный учет. Труды Института гидробиологии АН УССР. Выпуск: Дунайская сельдь и биологические основы ее промысла. 1953. № 28. С. 85–117.
6. Мороз В.Н. Характеристика состояния нерестового стада дунайской сельди (Alosa kessleri pontica Eichwald) в 1963–1967 гг. Вопросы ихтиологии. 1969. Т. 9. Вып. 4 (57). С. 640–650.
7. Мороз В.Н., Кротов А.В. Характеристика нерестового хода сельди (Alosa kessleri pontica Eichwald) в Дунай. Вопросы экологии и физиологии промысловых рыб и беспозвоночных Азово-Черноморского бассейна. 1969. Вып. 26. С. 80–87.
8. Павлов П.И. Биологическая и промысловая характеристика нерестового стада дунайской сельди. Труды Института гидробиологии АН УССР. Выпуск: Дунайская сельдь и биологические основы ее промысла. 1953. № 28. С. 118–173.
9. Правила промислового рибальства в басейні Чорного моря. Київ, 2023. URL: https://zakon.rada.gov.ua/laws/show/z1253-23#Text.
10. Промисловий вилов водних біоресурсів у водах України. 2025. URL: https://darg.gov.ua/_vilov_0_1023_menu_0_1.html. Дата звернення 06.05.2025.
11. Сердюк А.В. Дунайская сельдь / Сырьевые ресурсы Черного моря. Сб. научн. трудов. Москва : Пищевая промышленность, 1979. С. 215–223.
12. Ailloud L.E., Hoenig J.M. A general theory of age-length keys: combining the forward and inverse keys to estimate age composition from incomplete data. ICES Journal of Marine Science. 2019. Vol. 76. Iss. 6. P. 1515–1523.
13. Bănărescu P. Fauna of Romanian Popular Republic. Pisces-Osteichthyes. Bucharest : Romanian Academy Publishing House, 1964. 962 p.
14. Bertalanffy L. von. Untersuchungen über die Gesetzlichkeit des Wachstums. I. Allgemeine Grundlagen der Theorie; mathematische und physiologische Gesetzlichkeiten des Wachstums bei Wassertieren. Wilhelm Roux’ Archiv für Entwicklungsmechanik der Organismen, 1938. Bd. 131. H. 3. S. 613–652.
15. Gislason H., Daan N., Rice J.C., Pope J.G. Size, growth, temperature and the natural mortality of marine fish. Fish and Fisheries. 2010. Vol. 11. P. 149–158.
16. Gulland J.A., Holt S.J. Estimation of Growth Parameters for Data at Unequal Time Intervals. ICES J. Mar. Sci. 1959. 25. Р. 47–49.
17. Hoenig J.M. Empirical use of longevity data to estimate mortality rates. Fishery Bulletin. 1983. Vol. 81. Iss. 4. P. 898–903.
18. Hollander M., Wolfe D.A., Chicken E. Nonparametric Statistical Methods. 3rd ed. Hoboken : John Wiley & Sons, 2014. 848 p.
19. Ibănescu D.C., Popescu A., Nica A. Estimation of growth and mortality parameters of the Pontic shad (Alosa immaculata Bennett, 1835) in Romanian section of the Danube River. Lucrări Științifice-Universitatea de Științe Agricole și Medicină Veterinară, Seria Zootehnie. 2017. Vol. 67. P. 285–289.
20. Kolarov P. Biological Characteristics and Population Dynamic of Anadromous Fish Species: Ph.D. Thesis, Institute for Fish Resources. Varna, Bulgaria, 1985. 419 p.
21. Lagler K.F., Bardach J.E., Miller R.R., Passino D.M. Ichthyology. New York; London : John Wiley & Sons, 1977. 506 p.
22. Leonov C.M., Stroe M.D., Dima F.M., Vidu L., Nicolae C.G. Assessment of growth and mortality parameters of Alosa immaculata (Bennet, 1835) from the Danube Delta. Scientific Papers. Series D. Animal Science. 2023. Vol. 66. No. 1. P. 596–601.
23. Martiradonna A. Modelli di Dinamica Delle Popolazioni Ittiche: Stima dei Fattori di Incremento e Decremento Dello Stock. Tesi di Laurea Magistrale, Dipartimento di Matematica, Università di Bari. 2012.
24. Mocanu M., Oprea L., Crețu, M. Estimation of growth parameters and mortality rate of Pontic shad (Alosa immaculata, Bennett, 1835) in the Romanian sector of the Danube River, km 169-km 197. Scientific Papers. Series D. Animal Science. 2021. Vol. 64. P. 448–453.
25. Năstase A., Năvodaru I., Cernisencu I., Tiganov G., Popa L. Pontic shad (Alosa immaculata) migrating upstream the Danube River and larval drift downstream to the Black Sea in 2016. Scientific Annals of the Danube Delta Institute. 2018. Vol. 23. P. 57–68.
26. Năvodaru I. The Evolution of the Pontic Shad Populations in the New Ecological Conditions of the River and Measures to Maintain Them : Ph.D. Thesis, Dunărea de Jos, University of Galat, Galat, Romania, 1997.
27. Navodaru I., Nastase A. New data on presence of the great anadroumous migratory fishes in Black Sea – Marine zone of Danube delta biosphere reserve. Part I. New data on pontic shad (Alosa immaculata Bennet, 1835) migration and drifting larvae in Danube River. Deltaica, 3: Tulcea, 2014. 48 p.
28. Ricker W.E. Computation and Interpretation of Biological Statistics of Fish Populations. Bulletin of the Fisheries Research Board of Canada. 1975. Vol. 191. P. 1–382.
29. Rozdina D., Stoyanova Y., Terziyski G., Studenkov S., Karakushev B., Delov V., Mihaylov K., Kozhuharov D., Kutsarov Y., Kolev N., Nedyalkov N., Natchev N. Mapping the Distribution and Population Status of Alosa immaculata and Alosa tanaica (Teleostei, Clupeidae) in the Bulgarian Black Sea Area. Diversity. 2025. Vol. 17. Iss. 1 (38).
30. Schmutz S. Assessment of the Potential Transboundary Effects of the Construction of the Bystre Deep-Water Navigation Channel on Fish and Fisheries. Report to the ESPOO Inquiry Commission Vienna. 2006. 56 p.
31. Smederevac-Lali´c M., Kalauzi A., Regner S., Navodaru I., Višnjic-Jeftic Ž., Gacic Z., Lenhardt M. Analysis and forecast of Pontic shad (Alosa immaculata) catch in the Danube River. Iranian Journal of Fisheries Sciences. 2018. Vol. 17. P. 443–457.
32. Stroe D.M., Cretu M., Tenciu M., Dima F.M., Patriche N., Tiganov G., Dediu L. Age, Growth, and Mortality of Pontic Shad, Alosa immaculata Bennett, 1835, in the Danube River, Romania. Fishes. 2024. Vol. 9. Iss. 4.
33. Then A.Y., Honeig J.M., Hall N.G., Hewitt D.A. Evaluating the predictive performance of empirical estimators of natural mortality rate using information on over 200 fish species. ICES Journal of Marine Science. 2015. Vol. 72. P. 82–92.
34. Țiganov G., Grigoraș D., Năstase A., Păun C., Galațchi M. Assessing of Pontic Shad (Alosa immaculata, Bennett 1835) Stock Status from Romanian Black Sea Coast. Turkish Journal of Fisheries and Aquatic Sciences. 2023. Vol. 23. Iss. 3.
35. Tiganov G., Mihailov M.E., Danilov C.S., Oprea L. Analysis of the Danube shad (Alosa immaculata Bennett, 1835) along the romanian Black Sea coast during 2014. 16th International Multidisciplinary Scientific Geo Conferences SGEM: Proceedings. Albena, 30 June – 6 July 2016, Albena, Bulgaria, 2016. P. 703–710.
36. Tiganov G., Nenciu M.I., Danilov C.S., Nita V.N. Estimates of the population parameters and exploitation rate of pontic shad (Alosa immaculata Bennett, 1835) in the Romanian Black Sea coast. Agriculture for Life, Life for Agriculture: Proceedings. Bucharest, 7–9 June 2018. Bucharest, Romania, 2018. P. 162–167.
37. Yankova M. Preliminary estimates of the population parameters of four species in the Bulgarian Black Sea coast. International Journal of Latest Research in Science and Technology. 2014. Vol. 3. Iss. 5. P. 46–52.
38. Yilmaz S., Polat N. Length-weight relationship and condition factor of Pontic shad, Alosa immaculata (Pisces: Clupeidae) from the southern Black Sea. Research Journal of Fisheries and Hydrobiology. 2011. Vol. 6. Iss. 2. P. 49–53.
