Release of sturgeon of different age in the Kuban River
In 2019, the State Regional Centre of Sturgeon Gene Pool Conservation “Kubanbioresursi” (Krasnodar, Russia) made another step towards the rehabilitation of sturgeon populations in the Sea of Azov and Black Sea basin.
For the resumption of natural spawning for release 2019, individuals of five annual sturgeon classes born from 2019 to 2014, with weight ranged from 2.7 g to 3.6 kg had been selected. All fish were obtained from broodstock of the Centre, that comprises above 10 thousand adult individuals of five sturgeon species.
The inclusion into the program the release of different age graded fish during period from March to September allows to solve several challenges at once:
- to reduce food competition among released fish;
- to ensure maximum heterogeneity of species groups;
- to reduce significantly the period of stay in the wild prior the onset of sexual maturity (reduction of the total press of illegal fishing and adverse anthropogenic impact).
To ensure the best survival rate of the released fish, “Kubanbioresursi” Center staff uses an environmental-oriented approach, that comprises a system of adaptation measures for the reared fry, increasing its viability, as well an assessment of the swimming capacity, physiological state, reactions to the background color of the grow out tanks, sound of different frequencies, the presence of predators, etc.
The release of fish in the River Kuban was conducted in several stages in different parts of the river, located in the middle reaches.
Before the release of fish into a natural water body, a detailed survey of the River Kuban was fullfilled - in order to select the optimal places for release, that correspond to different age groups and each of the species released (food supply, depth, currents, etc.) and to minimize the impact of adverse factors on fish in stressful conditions (large water intakes, the impact of agro-industrial discharge, poaching etc).
In particular on June 13, 2019, beluga, Russian sturgeon and stellate sturgeon of different ages were released into the river. The Centre of Sturgeon Gene Pool Conservation “Kubanbioresursi is the only organization in the Azov Sea basin that carries out an annual releases of beluga into the wild. This year, beluga specimens of year 2018 generation of weigh above 600 g were released into the
On July 5, 2019 a release of ship sturgeon (A. nudiventris) specimens was conducted, during which three age groups (2014, 2018 and 2019 generations) of ship sturgeon were released in the Krasnodar Reservoir. Like last year, this release was one in a series of releases envisaged by the multi-year program of the restoration of the completely disappeared in the River Kuban ship sturgeon population.
In the following years, the Center plans to release mature, ready to spawn ship breeders directly onto natural spawning grounds in the river. This will ensure the replenishment of stocks not only with fish reared in the controlled conditions of the Center, but also born in their natural habitat.