Impact of environmental radiation on the health and reproductive status of fish from Chernobyl, Ukraine 2014 to 2015

Health and reproductive status was assessed in perch and roach of similar weight and length collected in September 2014, March 2015 and September 2015 from lakes in Belarus and Ukraine using gill nets of 20 m length and 21 mm mesh size to ensure capture of homogeneous groups of mature fish.

Relative abundance of fish species in each lake was evaluated by recording the number of fish caught for each species during an additional sampling session in June 2015. Scales were sampled for age determination. Body weight, total length, and presence of external signs of disease and macroscopic tumors were noted for each fish.

The Fulton condition index (K), hepatosomatic index (HSI) and gonadosomatic index (GSI) of fish were determined as K = body weight/ (total length (cm)3) x 100; HSI = (liver weight/body weight) x 100 and GSI = (gonad weight/body weight) x 100, respectively.

Lakes were selected according to hydrological properties and long-term exposure to a gradient of radiation dose. The lakes are situated at distances from 1.5 to 225 km of the Chernobyl NPP. Glubokoye, Yanovsky lakes and Cooling Pond are the high (H) contaminated lakes, Svyatoye Lake is a medium (M) contaminated lake, and Stoyacheye, Dvoriche and Gorova lakes are the low (L) contaminated lakes.