## 5 Conclusions and Recommendations  
During the meeting of the Kazakh-Russian Commission on the use of transboundary rivers held in Atyrau (2014), the ecological condition of the Ural River was called critical. This assessment is based on: the sharp reduction in water flow in the lower reaches, the high level of man-made contamination in the territory of the Russian Federation and the loss of conditions for natural reproduction of particularly valuable sturgeon species in the rivers. In 2016, Kazakhstan and the Russian Federation signed the agreement on the conservation of the Ural River ecosystem. The joint effort was planned to reduce cross-border river contamination, to protect fish resources, etc. However, measures to restore the ecological conditions of the river systems have not yet been undertaken. Therefore, in joint interstate negotiations on transboundary rivers it is necessary to pay attention to the acute problems of preserving the water resources of the Ural River. As shown by our research [21; 34; 41; 99], technogenic pollution of the surface waters of the Ural River basin has been increased all the time causing a strong disturbance of the ecological balance of the river ecosystems. A large amount of suspended matter, biogenic elements, heavy metals, and anthropogenic pollutants enter the river. According to long-term observations, there is a stable pollution of watercourses which by many parameters exceeds the MPC for open water bodies. Currently, there is a tendency of increasing pollution of the Ural River. In connection with the escalation of oil production in all sectors of the Caspian states, the ecological condition of the Caspian Sea is further aggravated. Even with the maximum observance of environmental safety measures, the use of modern technology, progressive methods of exploration, exploitation and oil transportation, pollution of the reservoir is not excluded [94; 95; 96; 97; 98]. Our study has proved that the main pollutants of the Caspian Sea are heavy metals, oil products, pesticides and polychlorinated biphenyls, which can accumulate in the muscles and in various organs of fishes. Against the background of high anthropogenic pollution of the northeastern part of the Caspian Sea, an intensive lake level decrease in this shallow water zone is responsible for further deteriorations of the ecological condition of this water area with serious consequences for the living conditions. Under the conditions of decreasing water masses, the concentrations of currently entering various toxic compounds in large quantities increase sharply. This can be the reason for the mass death of fishes, seals and other aquatic organisms living in this area. Under these conditions, the developed methodology for quantitative assessment of the ecological safety level for a part of the Caspian Sea, based on bioindication methods, makes it possible to monitor and continuously control the ecological stability of the Caspian Sea ecosystem continuously. Therefore, in order to preserve the normative quality of water resources in the Ural-C Caspian basin, the improvement of both the ecological conditions and habitat of hydrofauna is recommended in the following way:  
1. organize ecological monitoring of water bodies with the receipt of periodic relevant information to assess the pollution of water resources based on the proposed methodology, based on the integrated application of bioindication methods;
2. organize permanent monitoring of negative impact sources in the Ural River basin; \begin{table}
\begin{tabular}{c c} \hline \hline
**Level of Ecological Safety** & **Indicator (ES)** \\ \hline favourable & 70–100\% \\ \hline medium & 50–70\% \\ \hline nonfavourable & 30–50\% \\ \hline catastrophic & Less than 30\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Assessment of the ecological safety level.