The culture of sturgeons in Russia: production of juveniles for stocking and meat for human consumption
Post on 18-Sep-2016
The culture of sturgeons in Russia: production of juveniles for stockingand meat for human consumption
Mihail Chebanova, Roland Billardb*
a Krasnodar Research Institute of Fisheries, Krasnodar, Russiab Laboratoire dichtyologie, MNHN, 43, rue Cuvier, 75231 Paris cedex 05, France
Received 24 July 2000; accepted 26 March 2001
Abstract Culture of sturgeons in Russia began in the second half of the 19th century. During the first part of the 20th century, asignificant research effort was devoted to the control of reproduction and the rearing of larvae mostly for stock enhancementpurpose in rivers. Large-scale construction of hatcheries began in the 1950s after the damming of rivers, and by the 1980s over130 million 13-g juveniles per year were being produced from wild broodstock. Presently, the production is 100 million juveniles.Emphasis is now on optimising stocking results through consideration of fish-specific factors (e.g. behaviour, fitness, size, balancebetween species) as well as environmental variables (food availability, release sites, salinity, precipitation regime). Food fishproduction of sturgeon (market size is 1.52.0 kg is just beginning using captive broodstock and new growing technologies. In2000, farm production was about 1 650 t, which was higher than sturgeon landing from wild fisheries (1 500 t declared in 2000). 2001 Ifremer/CNRS/INRA/Cemagref/ditions scientifiques et mdicales Elsevier SASaquaculture / food fish / Russia / stocking / sturgeon
Rsum Llevage des esturgeons en Russie : production de juvniles pour le repeuplement et de chairpour la consommation humaine. Laquaculture des esturgeons en Russie a dbut dans la 2e partie du 19e sicle. Au dbut du 20esicle, un effort de recherche important a port sur la matrise de la reproduction et de llevage larvaire, principalement en vue durepeuplement des rivires. Aprs 1950, des closeries industrielles ont t construites et ont produit, dans les annes 1980,130 millions de juvniles par an, exclusivement partir de gniteurs sauvages. Actuellement, la production est de 100 millions dejuvniles et la tendance est loptimisation du repeuplement et un nouveau schma se met en place en prenant en compte le poissonlui-mme (comportement, aptitude survivre dans leur nouvel environnement, tailles, proportions entre espces relches) et sonenvironnement (disponibilits alimentaires dans les tangs dalevinage, nouveaux sites pour le dversement comme des rservoirsou des deltas lacustres, salinit, rgime des pluies). La production de chair pour la consommation humaine dbute avec laconstitution de stocks de gniteurs en captivit et lapplication de nouvelles mthodologies pour le grossissement jusqu la taillemarchande de 1,52 kg. La production russe a t denviron 1 650 t en 2000, ce qui est suprieur aux captures connues par pche(1 500 t). 2001 Ifremer/CNRS/INRA/Cemagref/ditions scientifiques et mdicales Elsevier SASaquaculture / poisson de consommation / Russie / repeuplement / esturgeons
1. HISTORY OF STURGEON CULTUREIN RUSSIA
The origin of culture of sturgeons in Russia began in1869 when Ovsjannikov succeeded in artificially fer-tilising sterlet (Acipenser ruthenus) eggs from theVolga river and the rearing of larvae (Milshtein, 1969).Sturgeon culture started concurrently with culture ofother fish species in the northern hemisphere after therediscovery of artificial insemination techniques used
for brown trout (Salmo trutta) by Remy and Gehain, inFrance, in the 1850s (Billard, 1989). Following thesuccess of Ovsjannikov, Russian scientists intensivelystudied artificial reproduction. They focused on wildspawners since it was impossible to hold large captivebroodstocks. Spawning attempts with captive freshwa-ter sterlet (whose maximum size does not exceed24 kg) were unsuccessful as the fish did not mature incaptivity (Grimm, 1905). In 1898, Berg also reportedexperiments on artificial breeding of Acipenser stella
*Correspondence and reprints.E-mail address: firstname.lastname@example.org (R. Billard).
Aquat. Living Resour. 14 (2001) 375381 2001 Ifremer/CNRS/INRA/Cemagref/ditions scientifiques et mdicales Elsevier SAS. All rights reservedS0990744001011226/REV
tus (Birstein and Bemis, 1997). Borodin (1898)worked with the stellate sturgeon, A. stellatus, and theSiberian sturgeon, Acipenser baerii, from several riv-ers and he developed the first procedure for artificialreproduction including the use of silt to remove thesticky layer surrounding the freshly fertilised eggs. In1912, Derjavin founded the Ichthyology Laboratory ofBaku and started his work on sturgeon reproduction,later summarised in his well-known book (Derjavin,1947). A decisive step was reached when Gerbilskij(1941, 1951, 1962), and his collaborators, such asBarannikova (1987), succeeded in stimulating ovula-tion using the method of hypophysation (pituitaryinjection). Development of the technology of artificialreproduction was completed after the basic work onoocyte maturation (Dettlaff and Skoblina, 1969) andsperm biology, fertilisation and development (Dettlaffet al., 1993). Work was also undertaken to use plank-tonic organisms as food for rearing fingerlings (Boga-tova, 1951) and a system for rearing crustaceans wasdeveloped by Gaevskaya (1941). Finally, an integratedtechnology for artificially rearing sturgeons in Russiawas elaborated. It was later published in the book ofStroganov (1968). During the first half of the 20thcentury, basic studies were being conducted on sys-tematics and on the biology of sturgeons (Berg, 1948).
By the middle of the 20th century, dam constructionstarted on the main rivers (Volga, Kura, Don, Kuban,Dniepr), and blocked upriver spawning migration.However, basic technologies were available for artifi-cial reproduction including induced spawning, artifi-cial insemination, incubation, larvae rearing on liveprey, either indoors or in outdoor small ponds (2 ha).These methods were then used in the hatcheries ondammed rivers. Eventually, the hatcheries reached anindustrial scale and produced large amounts of juve-niles for stocking at a size of 14 g, and this requiredabout 1 month.
Meanwhile the rearing of sturgeon in fish farms formeat consumption was less successful. One reasonwas the difficulty in maintaining captive broodstock ofsuch a large size. It was also assumed that broodfishmust be exposed to seawater during part of their lifecycle to reach maturity (later shown not to be neces-sary). Success came from the use of small sizedspecies living entirely in freshwater such as the sterletand A. baerii (Smoljanov, 1979). Both species weresuccessfully reproduced and the technology to breedA. baerii was fully established by the 1970s in theUSSR and later exported to other countries (e.g.France, USA, Italy, Japan, Germany and Poland).
Another solution to produce food fish was to usehybrids which had the characteristics of both parents.One example is the Bester, an intergeneric hybridmade between the sterlet A. ruthenus (male) whichlives in freshwater and the beluga Huso huso (female)which grows rapidly and reaches a large size. Thishybrid was created in 1952 by Nikoljukin (1964) andthe rearing technology was developed throughout the1960s (Burtzev, 1983). Many other sturgeon hybrids
have been created in Russia and other countries and, asexpected, hybrid sturgeon possesses a combination oftraits from each parent.
The objective of the present paper is to review therecent state of sturgeon production in Russia (juvenilesfor stocking in hatcheries and market-sized fish infarm structures). Quantitative data were obtained fromthe literature, unpublished official statistics from re-search institutes, and from data of the lead author (M.Chebanov).
2. PRODUCTION OF JUVENILESFOR STOCKING
2.1. Importance and efficiency of stockingThe release of juveniles in Russia is mostly concen-
trated in the Ponto-Caspian area and in Siberian rivers(figure 1). North of the Caspian sea, the release byhatcheries for all species was around 100 millionduring the years 19701980 and decreased to nearly70 million by the end of the 1990s, including theproduction by Azerbaijan. In the Sea of Azov area, theannual release by hatcheries was 9 million Acipensergueldenstaedtii and 19 million A. stellatus in19851990; after, the release increased for A. guelden-staedtii and declined for A. stellatus (table I). Juve-niles of both species were stocked at 23 g. In addition500 000 50-g H. huso and 200 000 A. ruthenus were
Figure 1. Geographic distribution of sturgeon State hatcheries ()and private sturgeon farms ([) in Russia (European part). Four farmsare also found in East Siberia and three in the far west and one Statesturgeon hatchery is located in East Siberia. Numbers in symbolsindicate the number of farms in that area.
376 M. Chebanov, R. Billard / Aquat. Living Resour. 14 (2001) 375381
released in 1999 directly by the Krasnodar ResearchInstitute and 2 million A. gueldenstaedtii by the Ukrai-nian authorities.
In the Siberian rivers, 2.5 million A. baerii and0.9 million A. ruthenus were released in 1999, as wellas 0.9 million of the local endangered population of A.baerii in lake Baikal. In addition, attempts wereperformed in the Amur river basin over the past2 years; from 1992 to 2000, Russians have stocked,each year, 3 million 5100-g Amur sturgeons Aci-penser schrencki and 1 million kaluga Huso dauricus(Svirsky, pers. comm.).
The efficiency of stocking is not precisely knownalthough some estimates have been established. Forexample in the Caspian sea from the 16 million 3050-d-old H. huso juveniles released annually in the 1970s,only 0.1 % were harvested (once they reached sexualmaturity) (Khodorevskaya et al., 1997). In the mid 90sthe commercial return of stocked fish was 0.07 % innumber for H. huso (Khodorevskaya, 1999). In thesame area, hatcheries contributed, for the years19911995, 98 % of H. huso, 55 % of A. guelden-staedtii and 41 % of A. stellatus catches (Khodo-revskaya et al., 2000). In the Sea of Azov basin, allrivers are dammed and there is no natural recruitment.Thus the present stocks have been, over the last10 years, entirely supported by stocking. The averagecommercial return was 0.46 % of those stocked overthe last 20 years. Commercial fishing is now prohib-ited except for a quota of 150 t spawners (males andfemales) allowed for the production of juveniles. Theavailability of females to fishermen is restricted to1215 d in the spring, during which the hatcheriesmust ensure the production of nearly 30 million juve-niles (table I). The selection of spawners is restrictedto females maturing in spring in the sea, in the mouthor in the lower course of rivers (dams are constructednot far from the sea, e.g. 150 km on the Kuban river).Late and early spawning runs are excluded fromreproduction. In addition, the run-off of water hasdecreased to 60 % of previous levels due to agricul-tural usage and has changed the dynamics of theupstream migration of spawners.
2.2. Research and new technologiesused in hatcheries
Research was carried out to improve the efficiencyof stocking operations in hatcheries. Efforts were madeto expand the period of reproduction, to make a better
use of the hatcheries and nursery capacities and tohave access to more genetically diversified popula-tions taking early and late spawning runs or fishmigrating far upstream (Chebanov and Savelyeva,1999). By using captive broodstocks, it is possible tocontrol the sexual cycle and spread the spawning timeover the year. By a combination of thermal andhormonal manipulations, ovulation and spermiationcan be obtained 5 months earlier or 6 months later thannormal. The process of maturation can be sloweddown by the exposure of females to low and slightlyoscillating temperatures (average 5 C). The criticalpart is the exposure to an oscillatory thermal regimewhen the fish are brought to the final stage of maturity(Chebanov, 1998). The spreading of the length ofperiod of reproduction also allows the inclusion ofwinter spawning stock in the stocking programmes.Nowadays the traditional sturgeon pituitary injectionsto induce ovulation are still practised in many hatch-eries but they are being replaced by synthetic ana-logues of the luteinizing hormone releasing hormone(LHRH). These analogues are potent at dosages as lowas 1 gkg1 (Goncharov, 1984). A technology forcollecting ovulated eggs instead of performing caesar-ean surgery has enhanced female survival after spawn-ing; it consists of making a small incision at the basalpart of the oviducts with a scalpel introduced throughthe abdominal pore (Podushka, 1999). Besides perma-nent captive broodstock, sperm banks were establishedby research institutions for ex situ conservation ofendangered populations (Ananiev, 1998); for instance,the federal living gene bank of the Azov and Blackseas, located at the Krasnodar Institute of Fisheries,contributes to the stocking programme of the localstate hatcheries.
2.3. Larvae rearingWhen released directly in rivers, the survival of
juveniles is only 13 % after a few months due topredation by other fish such as the European catfishSilurus glanis and the water intake for use in agricul-ture (including the killing of juveniles by the pumpingsystem); this reduction of the flow rate subsequentlyincrease salinity at the mouth of rivers (as seen in theKuban river) (Chebanov and Saveljeva, 1999). Re-search was conducted by the Krasnodar Institute andthe Temriuk hatchery (19921995) to improve thesurvival of juveniles for stocking by examining vari-ous cultural activities and stocking protocols (Che
Table I. Annual release of sturgeon juveniles in the Azov-Kuban region during 19741999, in millions of juveniles.
Years Acipenser gueldenstaedtii Acipenser stellatus Total both species(in millions)
Million % of total Million % of total
19741984 7.3 30.5 17.3 69.5 24.619851990 8.7 37.1 19.2 62.9 27.919911996 11.2 47.5 13.5 52.5 24.719971999 13.3 46.8 15.1 53.2 28.4
M. Chebanov, R. Billard / Aquat. Living Resour. 14 (2001) 375381 377
banov, 1998). It was shown that, in nursing ponds, thezooplankton biomass reaches 59 gm3 water within3 to 7 d after flooding the ponds. Larvae (6090 mg) ofA. stellatus and A. gueldenstaedtii released in thoseponds at the respective density of 80 000 and 70 000per ha can reach respectively 1.0 and 1.4 g within 15 d.Beyond 15 d, the plankton density decreased and thegrowth and the survival of the young sturgeons werepoor.
In practice, the rearing period in ponds should not belonger than 15 d at which time the juveniles are largeenough to be released and the ponds can be used againfor subsequent cohorts. Release of juveniles wasattempted into deltaic lakes and brackish water la-goons, which show a salinity gradient from 0 to 6 partsper thousands. In lagoons, the peak of natural produc-tivity occurred earlier than the traditional time ofrelease of A. stellatus (at 15 g) and A. gueldenstaedtii(at 2.5 g). Release at an earlier stage, when the fishwere 0.81.0 g for A. stellatus and 1.11.7 g...