Critical factors determining harp seal reproduction
https://doi.org/10.36038/0131-6184-2025-5-47-58
EDN: UTBDJA
Abstract
Since 2009, the harp seal (HS) trade in Russia has ceased; however, pup production in the White Sea population remains low. Published data on HS nutrition, the energy expenditure on reproduction, and the state of the food supply are reviewed to identify the causes of low pup production. It has been shown that GT females, like all representatives of the pinniped order, have high costs for offspring. To successfully reproduce, females must gain over 85% of their body weight. The high costs of HS reproduction place high demands on the provision of food resources for breeding females. A critical factor for HS females, ensuring successful pup production, is the abundant generations of spawning capelin. Intense food competition for capelin with abundant generations of Atlantic cod reduces the ability of HS females to successfully prepare for reproduction. It was also shown that the cessation of the GT fishery caused a change in the intrapopulation structure, population aging, and an increase in the proportion of K-strategists, which also reduces the population’s reproductive potential.
Keywords
About the Authors
A. I. Boltnev
The State Scientific Center of the Russian Federation Research Institute of Fisheries and Oceanography (VNIRO)
Russian Federation
Russian Federation
Alexander I. Boltnev – Doctor of Biological Sciences, Chief Researcher, Department of Marine Fisheries of the Far East
105187, Moscow, Okruzhnoy Proezd, 19
V. A. Belyaev
The State Scientific Center of the Russian Federation Research Institute of Fisheries and Oceanography (VNIRO)
Russian Federation
Russian Federation
Vladimir A. Belyaev – Doctor of Biological Sciences, Advisor to the Director
105187, Moscow, Okruzhnoy Proezd, 19
N. P. Antonov
The State Scientific Center of the Russian Federation Research Institute of Fisheries and Oceanography (VNIRO)
Russian Federation
Russian Federation
Nikolai P. Antonov – Doctor of Biological Sciences, Director of the Department of Marine Fisheries of Russia
105187, Moscow, Okruzhnoy Proezd, 19
References
1. Dorofeev S.V., Freiman S. Yu. (1928). The experience of quantitative accounting of the White Sea herd of Greenland seals by aerial photography // Proceedings of the Institute of Fisheries. Vol. 2. Issue 4. Pp. 12-23. (In Russ.)
2. Surkov S.S. (1963). On the issue of the methodology for determining the number and standards of selection of the White Sea bald// Proceedings of TINRO. Issue 15. Pp. 271-279. (In Russ.)
3. Chernook V.I., Kuznetsov N.V., Yakovenko M.Ya. (1999). Multispectral aerial photography of seal deposits // Murmansk: PINRO. 73 p. (In Russ.)
4. Chernook V.I. (2009) Results of instrumental aerial monitoring of the White Sea population of the Greenland seal in 1998-2008 // Biological resources of the White Sea and inland waters of the European North. Proceedings of the XXVIII International Conference on October 5-8, 2009, Petrozavodsk, Republic of Karelia, Russia. – Petrozavodsk: KarSC RAS. Pp. 601-604. (In Russ.)
5. Sidorov L.K., Bizikov V.A., Zabavnikov V.B., Egorov S.A. (2025). Assessment of reproduction of the White Sea population of the Greenland seal in 2023 and 2024 // Proceedings of VNIRO. Vol. 199. Pp. 64-85. (In Russ.)
6. International Council for the Exploration of the Sea [ICES] (2019b). ICES/NAFO/NAMMCO Working Group on Harp and Hooded Seals (WGHARP). Copenhagen: ICES. 193. doi: 10.17895/ices.pub.5617 ICES Scientific Reports 1. 72.
7. Boltnev A.I. (1991). Some information about the postnatal development of northern seals. In the book: “Research. biol. and the dynamics of numbers. fishing of the Kamchatka shelf” – Petropavlovsk-Kamchatsky, KOTINRO Publishing House. v.1. part 2. Pp. 137-149. (In Russ.)
8. Boltnev A.I. (2011). Maternal contribution to offspring during the prenatal period in the northern fur seals Callorhinus ursinus (Otariidae, Pinnipedia) // Zoological Journal. 1994. Vol.73. Issue 3. Pp. 126-135. (In Russ.)
9. Boltnev A.I. (2011). The Northern fur seal of the Commander Islands. Moscow – VNIRO. 264 p. (In Russ.)
10. Boltnev A.I., York A.E. (2001). Maternal investment in northern fur seals (Callorhinus ursinus): interrelationships among mothers’ age, size, parturition date, offspring size, and sex-ratios. // J. Zool. (Lond.). 254. Pp. 219-228.
11. Boltnev A.I., York A.E. and Antonelis G.A. (1998). Northern fur seal young: interrelationships among birth size, growth, and survival. Can. J. Zool. 76. Pp. 843-854.
12. Svetochev V.N. (2013). Biology and ecology of the Greenland seal (phoca groenlandica erxleben, 1777) of the White Sea population in the first year of life // Abstract of the candidate. Dissertation. – Murmansk: MMBI KSC RAS. 31 p. (In Russ.)
13. Svetochev V.N., Svetocheva O.N. (2018). Greenland seal: biology, ecology, fishing / V.N. Svetocheva, O.N. Svetocheva; [ed. by N.N. Kavtsevich]; Murmansk Sea. biol. Institute of the Kola Scientific Center of the Russian Academy of Sciences – Apatity: Ed. KSC RAS. 174 p. (In Russ.)
14. Nilssen K.T., Grotnes P.E., Haug T. & Potelov V. (1997). Seasonal variation in body condition of adult Barents Sea harp seals (Phoca groenlandica). // Journal of Northwest Atlantic Fisheries Science. 22. Pp. 17-25.
15. Kovacs K.M., Lavigne D.M. (2011). Maternal investment in Otariid seals and walruses // Canadian Journal of Zoology. 70(10). Pp. 1953-1964
16. Chapman D.G. (1961). Population dynamics of the Alaska fur seal herd // Trans. North. Am. Wildl. Nat. Res. Conf. V. 26. Pp. 356-369.
17. Chapman D.G. (1964). A critical study of Pribilof fur seal population estimates // U.S. Fish. Wildl. Serv., Fish. Bull. V. 63. Pp. 657-669.
18. York A.E., Hartley J.R. (1981). Pup production following harvest of female northern fur seals // Can. J. Fish. Aquat. Sci. V. 38. N 1. Pp. 84-90.
19. Craig A.M. (1964). Histology of reproduction and the estrus cycle in the female fur seal. // Callorhinus ursinus. J. Fish. Res. Board Can. 21(4). Pp. 773-811.
20. Helle E. (1980). Lowered reproductive capacity in female ringed seals (Pusa hispida) in the Bothnian Bay northern Baltic Sea with special reference to uterine occlusions. // Ann. Zool. Fennici 17. Pp. 147-158.
21. Ferguson S.H., Yurkowski D.J., Young B.G., Willing C. (2019). Do intraspecific life history patterns follow interspecific predictions? A test using latitudinal variation in ringed seals. // Popul. Ecol. Pp. 1-12. https://doi.org/10.1002/1438-390X.12008
22. Boltnev A.I., Boltnev E.A., Kornev S.I. (2022). Age of puberty, life cycle duration and reproductive contribution in female fur seals // Proceedings of VNIRO. Vol. 190. Pp.95-104. htpps://doi.org/10.36038/23073497-2022-190-95-104. (In Russ.)
23. Boltnev A.I., Boltnev E.A., Kornev S.I. (2023). Reproductive contribution in female fur seals due to the age of puberty // Proceedings of VNIRO. vol. 191. Pp.5365. (In Russ.)
24. Boltnev A.I., Boltnev E.A., Kornev S.I. (2023). Variability of fertility rates in female seals from different generations // Proceedings of VNIRO. Vol. 192. Pp. 17-25. ISSN: 2307-3497. https://doi.org/10.36038/2307-3497-2023-192-85-112. (In Russ.)
25. Stensen, G.B. Haug T., Hammill M. (2020). Harp Seals: Monitors of Change in Differing Ecosystems// Frontiers in Marine Science, September V.7:569258 Pp. 1-20. https://doi.org/10.3389/fmars.2020.569258
26. Grekov A.A., Drevetnyak K.V., Russkich A.A., Shamray E.A., Yaragina N.A. (2018). International fishing and the state of bottom fish stocks in the Barents Sea and adjacent waters// Proceedings of VNIRO. Vol. 174. Pp. 39-47. (In Russ.)
27. Grekov A.A., Dolgov A.V., Kovalev Yu.A., Mukhin V.A., Prozorkevich D.V., Sokolov K.M., Yaragina N.A. (2024). The state of domestic fisheries in the Northern fisheries basin at the beginning of the XXI century // Proceedings of VNIRO. Vol. 195. Pp. 12-23. (In Russ.)
28. International Council for the Exploration of the Sea [ICES] (2019a). “Barents Sea Ecoregion – Ecosystem overview,” in Report of the ICES Advisory Committee, 2019, (Copenhagen: ICES). https://doi.org/10.17895/ices.advice.5747ICES Advice 2019. Section 5.1.
29. Chernook V.I., Boltnev A.I. (2008). Regular instrumental aviation monitoring recorded a sharp decrease in the birth rate of the White Sea population of the Greenland seal, Marine mammals of the Holarctic: proceedings of the Fifth International Conference, Odessa, October 14-18, 2008 – Odessa: Pp. 100-104. (russ./eng.)
30. Haug T., Krøyer A.B., Nilssen K.T., Ugland K.I., and Aspholm P.E. (1991). Harp seal (Phoca groenlandica) invasions in Norwegian coastal waters: age composition and feeding habits. ICES J. Mar. Sci. 48. Pp. 363-371. https://doi.org/10.1093/icesjms/48.3.363
31. Boltnev A.I. (2017). Intraspecific r/K selection in the northern fur seal// Proceedings of VNIRO. Vol. 168. Pp. 4-13. (In Russ.)
32. Boltnev A.I. (2018). Marine mammals in an ecosystem: the population structure of a species as a consequence of r/K selection // In the collection “Marine mammals of the Holarctic: proceedings of the 9th International Conference, Astrakhan, 31.10-5.11. – Astrakhan. Pp. 76-84. (In Russ.)
33. Boltnev A.I., Antonov N.P., Boltnev E.A. (2023). Scientific foundations of the marine St. John’s wort fishery// In the collection “Topical issues of nature management, veterinary medicine and hunting: a collection of materials of the All-Russian scientific and practical conference with international participation dedicated to the 100th anniversary of Anna Ivanovna Kolevatova”. Editorial board: E. S. Simbirskikh (chief editors), M. S. Shevnina, V. N. Suleymanova [and others]. – Kirov: Pp. 126-133. (In Russ.)
34. Boltnev A.I., Antonov N.P., Boltnev E.A. (2023). Fishing as a factor in increasing the productivity of aquatic biological resources//In collection: “The Russian fisheries complex: problems and prospects of development.” Proceedings of the I International Scientific and Practical Conference (March 28-29, 2023, Moscow) – Moscow: VNIRO Publishing House. Pp.52-60. (In Russ.)
35. Antonov N.P., Boltnev A.I., Boltnev E.A. (2025). Changing the reproduction rate of a species and its population structure as a response to large-scale fishing// Proceedings of the XIII International Scientific and Practical Conference “Marine Research and Education (MARESEDU-2024)” Volume I (IV): [collection]. Tver: LLC “PoliPRESS”. Pp.500-507: ISBN 978-5-6053295-4-1. (In Russ.)
36. Boltnev A.I., N.P. Antonov, E.A. Boltnev (2025). r-K-population selection and response to fishing. “Modern methods of assessment and rational use of aquatic biological resources”. Materials of the II International Scientific and Practical Conference, Moscow, VNIRO Federal State Budgetary Budgetary Institution, November 18-22, 2024 /Compiled by D.A. Vasiliev, A.E. Bobyrev, A.I. Mikhailov, N.G. Zapadaeva, V.R. Sokolovsky. Moscow:/ VNIRO Publishing House. Pp. 35-40. ISBN 978-5-85382- 561-1. (In Russ.)
37. Nazarenko Yu.I. (1984). Biology and fishery of the White Sea population of the Greenland seal // In: Marine Mammals, Moscow: Nauka. Pp. 109-117. (In Russ.)
Review
For citations:
Boltnev A.I., Belyaev V.A., Antonov N.P. Critical factors determining harp seal reproduction. Fisheries. 2025;1(5):47-58. (In Russ.) https://doi.org/10.36038/0131-6184-2025-5-47-58. EDN: UTBDJA
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