The Effect of Temperature on the Toxicity of Petroleum and Potassium Dichromate on the Tilapia Sarothenodon vulcani

Abstract

Sublethal doses of petroleum (1 ppm) and potassium dichromate (130 ppm) are mixed in two separate tanks. Sarothenodon vulcani are placed in the 2 tanks for 24, 48, 72, hrs. Temperatures are then increased in the 2 tanks. By counting mortalities and using statistical test (L=.10) proved that an increase in temperature causes an increase in the toxicity of the 2 pollutants in S. vulcani. The induced effect of the temperatures potentiates the lethal effect of each pollutants. Histological findings reveal that a temperature aggravates the lethal effects of the 2 pollutants in terms of the cellular (especially in muscles and gills) and physiological processes in S. vulcani. As an of shoot this affects the behavioural patterns of the fish under stress. In temperatures 30o – 38o C, lethality in petroleum increases 13 times a 100% kill, while on potassium dichromate mortality increases 6 times of 100 % kill at temperatures 32o – 38o C. Since optimal temperature of S. vulcani is from 14oC- 42oC, sublethal concentration of pollutants lowers the optimal temperature and degree of survival. PH and dissolve oxygen (DO) play a part in these effects since with the presence of pollutants the PH is affected while the presence of increasing temperature the solubility of oxygen is changed. This paper describes the ill-effects of pollution and recommends that “palay-isdaan” farmers prevent any of these pollutants from entering the physiological systems of their cultures.