Ian Davin C. Rosales Benjamin E. Palmares, Jr. Eric Vincent V. Rivas (January 2004)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
The study is aimed at determining the effect of lead pollutant to percent mortality of milkfish fingerlings. Specifically, the study intends to measure the tolerance of bangus fingerlings to lead pollutant, thru varying degrees of lead concentrations, and the percent mortality of fingerlings after a 24-hour exposure period. The study sought answers to the following question: Will increasing concentration of lead pollutant in the water affect the mortality of milkfish fingerlings? For this purpose a range finding test was conducted to establish the mid-lethal concentration, which is 50% mortality of the total number of fingerlings that were initially exposed to the pollutant. Once determined, a random sampling was made with the test specimen samples. For lead tolerance, the following activities were undertaken: a) exposure of healthy samples to lead contaminated water for 24 hours; and b) record the physical reactions of samples to contaminated water.
One way analysis of variance at 0.05a was used to determine if there is a significant difference in the percent mortality of fingerlings that had been exposed to increasing concentration of lead for 24 hours. Two set of tests were conducted which established the mid-lethal concentration at 300 ppm, and that at 350 ppm almost all the test fingerlings were killed. Five increasing lead concentrations at 25 ppm intervals were used. The results of the experiment showed that there is a significant difference in the percent mortality of fingerlings as the amount of lead concentration is increased.