Caspian Sea: State of the Environment 2019

Another reason why particular attention has been paid to sturgeon in the aquaculture sector is the specific genetic make-up of the species, which may offer an advantage for preserving ge- netic diversity even when breeding under artifi- cial conditions (Apostle 2017). Compared with natural conditions, the pondmeth- od reduces unavoidable losses of larvae and juve- niles by 10-15 per cent and accelerates the matu- ration of caviar-producing fish from 7–8 years to 5 years. By strictly complying with scientific and technical regulations and applying the latest devel- opments and advanced technologies in the field of aquaculture, Hazar Balyk was able to achieve signif- icant results in breeding sturgeon at its production complex within two years (Bobkin 2017). It is believed that commercial aquaculture makes a positive contribution to sturgeon conservation by providing economic incentives, since it is the only legal way to produce sturgeon caviar in large quantities, meet market demand and provide an alternative to illegal caviar. The development of aquaculture to protect sturgeon stocks in the Cas- pian could reduce the attractiveness of illegal fish- ing by satisfying the market and lowering prices.

and heavy metals, genetic contamination and contamination with unwanted species of phyto- plankton and zooplankton (Martinez-Porchas and Martinez-Cordova 2012). Consequently, ensuring that aquaculture is beneficial to the local population and to the environment will be a difficult task, requiring consideration of all potential impacts. Sturgeon species are considered to be at greater risk of extinction than any other group of species (Gessner et al. 2010). They are endangered by “... overfishing, habitat degradation, pollution and hydroelectric power station dams that prevent them from reaching breeding sites, as well as by an absence of effective international legal regulation and by organized criminals seeking quick prof- its” (Apostle 2017). About 90 per cent of sturgeon fishing in the post-Soviet space was conducted in the Volga, the river that is also home to the most important spawning grounds. This commercial fishing and the development of hydropower are important reasons behind the dramatic popula- tion decline in recent decades. It has been sug- gested that sturgeon aquaculture could provide a solution to the problems of falling fish stocks and illegal fishing (Ruban et al. 2015).

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