Brief international report about scientific work on the Big Aral Sea 

Aralsk Section of Fish Institution October 1998.

 

 

 

 

Financial crisis in Republic of Kazakstan did not let Aral Section of Fish Institute to have scientific work in the whole Aral Sea. In the last years our organisation was devoting its work only to the Small Aral Sea. Since 1992 there was no work in the Big Aral Sea. Due to the financial support from Danish side after the 6 years  break (1992-1998) first time in October 1998 together with Danish scientists Jan Larsen and specialists from Aralsk section were spent over-all hydrochemical, toxicological, hydrobiological and ichthyological exposure in the northern part of the Big Aral sea ( Tyshibas Bay, Chernyshova) and in the western part of the Small Aral Sea ( Shevchenko Bay). In the result of scientific expedition these questions were studied:

-         Hydrobiological routine in the northern part of the Big Aral Sea (temperature, flowing, transparence, and etc.)

-    hydrochemical routine ( saltiness, gas routine , oxidation, and etc.)

-         the level of accumulation of toxinís in water in the Aral Sea

-         The level of the accumulation pesticides in the organ and tissue of the kambala -glossas

-         the fodder basis of the sea ( zooplancton, bentos) and deternmined the character of     

distribution zooplancton, bentos in the Big Aral Sea with the different salinity in the areas of water.

-         the level of providing kambala-glossa with fodder in the condition of changing salinity routine of the sea,

-         the state of kambala-glossa ( size, weight, dynamics of quantity and biomass),

-         the migration of kambala-glossa in the northern part of the Big Aral Sea, determined the place and time of its concentration.

Collected scientific material during expedition (from the 29th of September till the 30th of October 1998) totally worked up and prepared scientific report about value the fishing stock of kambala-glossa  in the Aral Sea by scientists of Aral section of Fish Institute. In the result of analyses, collected scientific material about the Aral Sea in October 1998 it is possible to make this conclusion:

-         hydrophisical indices , dissolved gases and organically things are in the optimal level for vital activity of kambala-glossa and other water animals.

-         Intensive forming of initial product in the Big Aral Sea in the autumn is not very high as a result of depressed state of phytoplancton.

-         The most progressive growing of salinity is used for Tushibas Bay Big Aral Sea (67-67.5prml). Under the influence of underground water the salinity in Bay Chernyshova is less than in Bay Tyshibas (56-59prml).

-         For Bay Shevchenko Small Aral Sea is stable level of salinity for last years (23-25prml).

-         Diapason of salinity from 20 till 56 prml is in optimal for vital activity of Kampala, adapted in the conditions of the Aral Sea.

-         the level of pesticides pollution of the Aral Sea is not high, mostly there is registered stable chloroorganical pesticides (COP).

-         The source of pesticides in the sea is fives flow and atmosphere transfers, in the muscle tissues there is registered stable chloroorganical pesticides ( GCSG and DDT) percent of its frequency in the muscles is low .

-         Very low level of accumulation of toxins is in the carviar of Kampala .

-         Residual concentration of pesticides in the muscles of Kampala in October 1998 was lower than in 1991-1992.

-         registrated in October 1998 the level of concentration of pesticides in Kampala muscles in the Aral Sea is lower in 2-3 times than maximum permissible  level corresponding  to norm for food Fish products,

-         Quantity and biomass of zooplancton and also bentos are higher and this provides  the good tempo of growing kambala-glossa in the Aral Sea, calculation showed that at the present time the fishing stock of kambala -glossa in the Big Aral Sea is about 24.000 tone and in the Small Aral Sea there is 4.500 tone. Nowadays the stock of Kampala is enough for organising here effective fishery.

In the conclusion I would like to say that due to the support from Danish side and especially providing with high passable transport, after six years break ( 1992-1998) first time we were able to spend scientific works on places of the Big Aral Sea which were located in distance of 400-500 km. from Aralsk city. Jan Larsen brought with him equipment for determining the exact location of station ( co-ordinate), reservoir  for fixing zooplancton and bentos, equipment for marking Fish that let us determine Kampala migration.

From kazak side we invited high quality specialists, doctor of Geography Science Ė Amirgaliev N.A. During common work there was constant changing with information in

hydrochemical, toxicological, hydrobiological, and ichthyological fields, including methods of collecting and working with materials. All works was spent in atmosphere of mutual understanding and support. From Aralsk section, there were six people, who had been before on a leave, without payment for three months. Because of reducing financing of scientific investigations in the Aral Sea, 5 people had possibility to return for their scientific works, even for short period and at the time to earn money for their families. Process in the ecosystem of the Aral Sea does not have analogue in the world thatís why results about the autumn scientific works could interest scientists from different countries.

We are grateful for Danish for their invaluable contribution in studying the present ecosystem of the Aral Sea. The continuation of studying the present ecosystem of the Aral Sea has great scientific-theoretical and practical meaning. This work will make invaluable contribution for the fishery importance of the Aral Sea.

Director of Aral section of Fish Institute

Ermahanov Zaulhan.