Fish diversity and fisheries in the Caspian Sea and Aral–Syr Darya basin in the Republic of Kazakhstan at the beginning of the 21^st Century

For many years fishing was one of the most important human activities in the Caspian Sea and Aral-Syr Darya basin. This article summarizes the results of research conducted by the authors during 1991–2010. Drastic shifts in commercial fish catches as well as in fish diversity were revealed for both the Caspian Sea and the Aral-Syr Darya areas as a result of overfishing, poaching, exotic species introduction, and habitat alterations. The policies of the government authorities in the field of nature protection, especially those involving fish resources, may be characterized by the adoption of controversial and inconsistent decisions and subsequent restructuring of those state institutions charged with nature protection that resulted. These policies did not promote sustainable use of nature resources and will have long-lasting impacts on the protection of fish and other aquatic biological resources. Some recommendations are provided for attaining sustainable fisheries management in the North Caspian and Aral regions.