Effects of pulp and paper mill effluent (BKME) on physiology and biochemistry of the roach (Rutilus rutilus L.)

The effects of bleached kraft pulp and paper mill effluent (BKME) on the roach (Rutilus rutilus L.) were studied under experimental and natural field conditions. In the acute experiment (72 h exposure to the concentrated BKME), the roach suffered from a general stress syndrome, characterized by a significant increase of cortisol and blood glucose, as well as a significant decrease of leucocrit and total plasma protein. In three weeks' exposure in a polluted and an unpolluted lake and in fish caught from the same lakes, the more specific effects of BKME treatments appeared. During the three weeks' exposure, slight hyperglycaemia as well as a decrease in a transaminase activity (GPT) and increase in the plasma total protein concentration of the fish occurred in the polluted lake. Fish caught from the polluted lake exhibited lower values of haematocrit, transaminases (GOT and GPT), and calcium concentration plus a higher chloride concentration in the plasma than in the unpolluted lake. The differential leukocyte counts also showed slight differences: Fewer lymphocytes and more granulocytes were found in roach from polluted waters. The morphology of the red blood cells in the roach from polluted lakes had more elongate erythrocytes with a longer major axis and a shorter minor axis than in fish from the polluted lake. The possibilities of determining the origin of fish based on their erythrocyte morphology is discussed.