Ribogospod. nauka Ukr., 2016; 4(38): 52-63
DOI: https://doi.org/10.15407/fsu2016.04.052
УДК 639.215[(477)(262.05)]

Dynamics and structure of the herring (Alosa immaculata) catches in the Dniester estuary during the 1994–2016 years

S. Snigirov, This email address is being protected from spambots. You need JavaScript enabled to view it. , Odesa National I. Mechnikov University, Odesa

Purpose. To assess the current state of the Pontic shed in the Dniester estuary.

Methodology. Ichthyological samples has been collected in the Dniester estuary according to standard methods. Fish has been caught using gill nets with 30–32 mm mesh size. The methodical guidelines "Metodiki zboru і obrobki іhtіologіchnih і gіdrobіologіchnih materіalіv z metoju viznachennja lіmіtіv promislovogo viluchennja rib z velikih vodoshovishh і limanіv Ukrayiny" (Кyiv, 1998) and "Metodicheskie ukazanija po ocenke chislennosti ryb v presnovodnyh vodoemah" (Moskva, 1990) were used for fish stock assessment. The dynamics of water discharge in the Dniester River was presented based on the observations at gauging stations in Bendery and Tiraspol.

Findings. The data of catch dynamics, age and sex composition, length-weight characteristics of the Pontic shed Alosa immaculata Bennett, 1835 in the Dniester estuary 1994–2016 have been presented in the paper. According to official statistics data, the annual catch of the Pontic shed in the Dniester River and Dniester estuary in 1996–2016 ranged from 1.3 to 62.0 tons, with an average of 24.6 tons — 9.8% of the total catch of the Pontic shed in the Danube-Dniester interfluves.
A dependence of catch amounts on the water regime of the Dniester River has been observed. An increase in the water flow rate in the river during the spring flood in full-flowing years (annual flow of more than 10 km3), contributes to an increase in the Pontic shed catch in the Dniester estuary. Currently, catches are dominated by age-3 (40.5–59.2% of the total catch) and age-4 (30.7–42.0%) fish. Older age groups are not numerous. Sex ratio was unequal. Females predominated in the control catches, accounting for 65.4% of the total catch. The stock of the Pontic shed entering the Dniester estuary in 2016 was estimated to be 221.0 tones. We recommended to extend the ban of the specialized Pontic shed fishing during the spawning period.

Originality. The current state of the spawning stock of the Pontic shed population in the Dniester estuary is presented.

Practical value. It is recommended to change the timing of the ban on the specialized Pontic shed fishing in the Dniester estuary, to ensure the passage of a greater number of individuals to the spawning grounds.

Keywords: Dniester, Dniester estuary, herring (Alosa immaculata), catch dynamics.

REFERENCES

1. Bushuev, S. G. (1996). Sovremennye dannye o sostoyanii nerestovogo stada dunayskoy sel'di A. kessleri pontica (Eichwald, 1838) v 1994–95 godakh. Tr. YugNIRO, 254-258.
2. Kukuradze, A. M. (1964). Osobennosti nerestovogo khoda dunayskoy sel'di Caspialosa caspia nordmanni (Antipa) v 1961 g. Vopr. ikhtiologii, 4, 2 (31), 387-389.
3. Mezhzherin, S. V., & Fedorenko, L. V. (2007). Morfologicheskaya struktura populyatsiy sel'di Alosa pontica s.l. (Clupeiformes, Alosiinae) Dunaya i ee izmeneniya za 50-letniy period. Vestnik zoologii, 41, 2, 131-141.
4. IRH UAAN. (1998). Metodyka zboru i obrobky ikhtiolohichnykh i hidrobiolohichnykh materialiv z metoiu vyznachennia limitiv promyslovoho vyluchennia ryb z velykykh vodoskhovyshch i lymaniv Ukrainy. Kyiv.
5. Sechin, Ju. T (Ed.). (1990). Metodicheskie ukazanija po ocenke chislennosti ryb v presnovodnyh vodoemah. Moskva : VNIIPRH.
6. Moroz, V. N. (1969). Kharakteristika sostoyaniya nerestovogo stada dunayskoy sel'di Alosa kessleri pontica Eichw. v 1963-67 gg. Vopr. ikhtiologii, 9, 4 (57), 640-650.
7. OdTs YugNIRO. (2013). Otsenit' sostoyanie promyslovykh ob"ektov vo vnutrennikh vodoemakh Severo-zapadnogo Prichernomor'ya i na prilezhashchem shel'fe Chernogo morya, izuchit' dinamiku ikh chislennosti dlya opredeleniya vozmozhnykh limitov iz"yatiya i regulirovaniya rybolovstva, razrabotat' dolgosrochnye prognozy promyslovoy obstanovki : Otchet po NIR. Bushuev, S. G. (Ed.). Odessa.
8. OdTs YugNIRO. (2015). Otsenit' sostoyanie promyslovykh ob"ektov vo vnutrennikh vodoemakh Severo-zapadnogo Prichernomor'ya i na prilezhashchem shel'fe Chernogo morya, izuchit' dinamiku ikh chislennosti dlya opredeleniya vozmozhnykh limitov iz"yatiya i regulirovaniya rybolovstva, razrabotat' dolgosrochnye prognozy promyslovoy obstanovki : Otchet po NIR. Bushuev, S. G. (Ed.). Odessa.
9. Pavlov, P. I. (1953). Biologicheskaya i promyslovaya kharakteristika nerestovogo stada dunayskoy sel'di. Tr. In-ta gidrobiologii AN USSR, 28, 118-173.
10. Pravdin, I. F. (1966). Rukovodstvo po izucheniyu ryb (preimushchestvenno presnovodnykh). Moskva : Pishch. prom-st'.
11. Serdyuk, A. V. (1979). Dunayskaya sel'd' (Alosa kessleri pontica Eichw.). Syr'evye resursy Chernogo morya. Kerch': AzCherNIRO, 215-223.
12. Chugunova, N. I. (1959). Rukovodstvo po izucheniyu vozrasta i rosta ryb. Moskva : Izd-vo AN SSSR.
13. Bertalanffy van, L. (1938). A quantitative theory of organic growth. Hum. Biol., 10, 181-213.
14. Beverton, R. J .H., & Holt, S. J. (1956). A review of methods for estimating mortality rates in fish populations, with special reference to sources of bias in catch sampling. Rapp. P.-V. Reun. CPIEM, 140, 67-83.
15. Beverton, R. J .H., & Holt, S. J. (1966). Manual of methods for fish stock assessment. Part II. Tables of yield function. FAO Fish. Biol. Tech. Pap., 38.
16. Pauly, D. (1980). On the interrelationships between natural mortality, growth parameters and mean environmental temperature in 175 fish stocks. J. Cons. Int. Explor. Mer., 39, 175-192.
17. Ricker, W. E. (1975). Computation and interpretation of biological statistics of fish population. Bull. Fish. Res. Bd. Can., 191.
18. Otsenka vozmozhnosti sozdaniya reguliruemogo nerestilishcha na pravom beregu Dnestra. 2.unece.org. Retrieved from https://www.2.unece.org/ ehlm/32931845/Feasability_Study_SpawningPlace_rus_print.pdf.