Fish book son indd

G.M.Palatnikov,  R.U.Qasimov
154
STURGEONS AND THE PROBLEM OF 
BIODIVERSITY PRESERVATION
Biodiversity – an abbreviation for biological diversity; means the variation 
of life forms in all its manifestations, from genes to the biosphere. A great deal 
of att ention began to be paid to the study, use and preservation of biodiversity 
following the signing by many countries of the United Nations Convention on 
Biodiversity (United Nations Conference on Environment and Development 
(UNCED), Rio de Janeiro, 1992). 
There are three main levels of biodiversity:
genetic diversity
− 
 refl ecting intraspecifi c diversity and is caused by 
the variability of individuals;
species diversity 
− 
refl ecting the diversity of life forms (plants, animals, 
mushrooms and microorganisms). At present around 1.7 million species have 
been described, although some estimates bring their total number up to 50 
million;
ecosystem diversity 
− 
covering the diversities between diff erent types 
of ecosystems, diverse habitats and ecological processes. Ecosystem diversity 
is identifi ed not only in terms of structural or functional components but also 
in terms of scale, from microbiogeocenosis to the biosphere.
Sometimes landscape diversity, refl ecting the specifi c features of an area 
and the impact of local, regional and national social cultures, is identifi ed as 
a separate category.
All the levels of biological diversity are interconnected: genetic diversity 
promotes species diversity. Ecosystem and landscape diversities create the 
conditions for the evolution of new species. Enhancing species diversity leads 
to an increase in the overall genetic potential of life forms in the Biosphere. 
Each species contributes to the diversity, so from this point of view there is no 
such thing as a useless or harmful species.
Species are not distributed evenly over the Earth. Species diversity is 
consistently richer in the tropics and reduces towards the poles. The most 
species-rich ecosystems are the tropical rainforests, which cover nearly 7 
percent of the surface of the globe and contain more than 90% of all species. 

---

Sturgeons – contemporaries of dinosaurs
155
Through the geological history of the Earth the biosphere has experienced 
a constant process of species appearing and disappearing; all species have 
a  fi nite period of existence. Extinction has been compensated for by the 
appearance of new species and, as a result, the total number of species within 
the biosphere rose. The extinction of species is a natural evolutionary process 
that takes place without human intervention.
In the last century human activity resulted in a species extinction rate 
estimated at 40,000 times the natural extinction rate (according to some estimates). 
The eff ect of anthropogenic factors is leading to a reduction in biodiversity due 
to the elimination (extinction or destruction) of species. The irreversible and 
unbalanced destruction of the unique gene pool of our planet is taking place. 
Species elimination as a result of human activity may take place in two 
ways: direct extirpation (hunting, commercial fi shing) and indirect extirpation 
(destruction of habitat and disruption of trophic interactions). Over-hunting 
is the most obvious direct cause of biodiversity reduction; however as a cause 
of extinction it has much less impact than the indirect causes of habitat change 
(for example, those linked to the chemical pollution of rivers or devastation 
of forests). 
In the case of the sturgeon we can observe both forms of elimination 
together. On the one hand, we have excessive, virtually uncontrolled, fi shing. 
On the other hand, we have habitat disruption due to pollution by industrial 
and household wastes.
Many countries establish Red Books, lists of rare and nearly extinct life 
forms, to keep a record of species on the brink of extinction. Most sturgeon 
species are currently included in the International Red List.
There are many reasons why biodiversity must be preserved: the 
requirement for biological resources to satisfy the needs of mankind (food, 
materials, drugs etc.), for reasons of ethics and aesthetics (the inherent worth of 
life) and so on. However, the main reason why biodiversity must be preserved 
is that it plays a key role in ensuring the sustainability of ecosystems and 
the biosphere as whole (absorption of pollutants, climate stabilization, and 
providing conditions suitable for living in.) 
Biodiversity performs a regulatory function in all the biogeochemical, 
climatic and other processes on Earth. Each species, no matt er  how 
insignifi cant it may seem, contributes to the sustainability of not only its ‘own’ 
local ecosystem, but also of the entire Biosphere. Biodiversity preservation is 
an inseparable part of the Sustainable Development of mankind.

---

G.M.Palatnikov,  R.U.Qasimov
156
The term ‘sustainable development’ means the development of society 
in such a way that ensures that today’s needs are met without damaging the 
ability of future generations to meet their needs.
Should we lose the Caspian sturgeons today, we will deprive ourselves 
and our successors of one of the most valuable sources of protein-based food; 
we will lose the unique gene pool of the sturgeon, which has evolved over 
millions of years, and, as the result, we lose genetic diversity.
SO HOW CAN WE SAVE THEM?
Long ago, sturgeons lived in all the rivers and seas of the Northern 
Hemisphere. In the mid-XIX century there was a sturgeon market in Hamburg 
(Germany), which sold between 4,000 and 5,000 adult fi shes a year; these 
fi shes were caught nearby, in the mouth of the Elba. During the fi rst half of 
the XX century, the Caspian Sea accounted for 70% and in the second half for 
90% of world’s sturgeon catches. The fact that sturgeon hauling reduced from 
400,000 hwt early in the XX century to 250,000 hwt in 1970 and to 9,000 hwt in 
1999, is a numerical expression of the disaster that has befallen the sturgeon 
populations of the Caspian Sea.
Over-fi shing in the densely populated areas of Europe and America has 
also greatly impacted the sturgeon populations.
Power station dams which blocked the natural migration routes of these 
species to the spawning grounds upstream in major rivers have signifi cantly 
aff ected sturgeon populations. Dams built for the hydrostations on the Kura 
and Volga rivers have cut the fi sh off  from the routes to spawning grounds 
further up these rivers. To compensate for this damage, the fi rst experimental 
sturgeon plant was installed in the former USSR, on the Kura River in 
Azerbaij an.  Scientifi cally substantiated methods of raising young sturgeon 
artifi cially were developed at this plant under the supervision of A.N. 
Derzhavin, N.L.Gerbilsky and R.Yu.Kasimov. Later on, similar plants were 
installed on the Volga, Don and Kuban, as well as in Iran and the USA. These 
plants are engaged in catching spawners, obtaining reproductive products, 
artifi cial incubation of roe, maturing fries and raising young individuals.
To synchronize spawning among the spawners they are given injections 
of acetonated pituitary. Aft er the injection the spawners are kept at a constant 
temperature or in an increased temperature environment. The point when 
the female is ready (transition of roe to ovulation) is determined by visual 
inspection and pressing its belly.

---