Abstract
This article presentsthe results of a study on the content of heavy metals and radionuclides in the muscle tissue of the long-clawed crayfish (Pontastacus leptodactylus) collected from major commercial water bodies of the West Kazakhstan region: reservoirs along the Koshym River, the Bolshoy and Maly Uzen rivers, and Lake Saryshyghanak. Within the scope of the study, samples of crayfish, fish, water, and bottom sediments were analyzed using spectrometric methods in accredited laboratories. The main toxic elements identified were lead, cadmium, cesium-137, and strontium-90. Among the heavy metals, the lowest cadmium concentration was found in crayfish from the Maly Uzen River, while the highest was observed in samples from Lake Saryshyghanak. The highest lead levels were detected in crayfish from the Koshym River and the lowest in samples from the lake. The concentration of toxicants in crayfish tissue 192exceeded that of the surrounding environment, yet remained well below the maximum permissible levels established by sanitary and technical regulations. Therefore, the meat of these crayfish can be considered ecologically safe. Additionally, crayfish have proven effective as bioindicators of the ecological status of aquatic ecosystems. The results hold scientific and practical value in the areas of food safety, ecology, and sustainable use of aquatic biological resources