Research of acute influence of new fertlizer ?Rost-concentrate? on the hydrobionts Сyprinus carpio L. and Daphnia magna Straus

Purpose. To establish and assess acute toxicity parameters of "ROST-concentrate (10+7+7)" acute toxicity for planktonic crustacean Daphnia magna Straus and carp fingerlings Cyprinus carpio L. Methodology."ROST-concentrate (10+7+7)" contains macronutrients (nitrogen, phosphorus, potassium), which are valuable for the pond ecosystem, and trace elements in environmentally safe chelate form. We determined the vital (LC0), absolutely lethal (LC100) and median (LC50) drug concentrations on the test organisms such as crustacean D. magna (Cladocera) and carp fingerlings C. carpio. The determination of acute lethal toxicity on D. magna was conducted according to DSTU 4173: 2003 that corresponded to the international standard ISO 6341: 2012, MOD [7]. The temperature of the experiment was 20±0.5 oC. The exposure time - 96 hours. Daphnia were not fed. Following "ROST-concentrate (10+7+7)" concentrations were tested: 100; 75; 50; 25; 10; 1; 0.5; 0.1; 0.05; 0.01; 0,005; 0,001 ml/dm3. We also determined the acute lethal toxicity on carp fingerings with an average weight of 6.78±0.63 grams following the standardized procedure [8]. Pond water was used in the experiment. Ten fish were placed into a 40 L aquarium. Following concentrations of "ROST-concentrate (10+7+7)" were investigated: 0,5; 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 15; 20; 30; 40 mg/L. The exposure time was 24 hours. Water temperature was 19±1oC. LC50 drug median concentration was calculated according to G. Kerber method. Findings. The parameters of integral acute toxicity of "ROST-concentrate (10+7+7)" on typical organisms of fish pond ecosystems.With 96 h exposure on juvenile cladoceran D. magna, lethal concentration was LC100 = 5,00 ml/dm3, median concentration was LC50 = 0,15 ml/dm3, vital concentration was LC0 = 0,01 ml/dm3. According to the classification of toxic substances, the "ROST-concentrate (10+7+7)" is characterized by low toxicity on juvenile cladoceran D. magna. With 24 h exposure on carp fingerling: lethal concentration was LC100 = 40,0 ml/dm3, median concentration was LC50 = 18,6 ml/dm3, vital concentration was LC0 = 7,0 ml/dm3. According to the classification of toxic substances [11], "ROST-concentrate (10+7+7)" was practically nontoxic to 6.78 ± 0.63 g carp juveniles. Originality. First study of the acute effect of organic-mineral preparation "ROST-concentrate (10+7+7)" on planktonic cladoceran D. magna and carp juvenile C. carpio. Practical value. The obtained results show a very low level of toxicity of the drug and safety for organisms of fish-breeding pond ecosystem organisms after its application.