Mitzi Kate S. Bagsit (March 2009)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Water pollution is causing the world a great damage today. Living organisms are now depleting in number due to this problem. One way to prevent their total extinction is to revive the safe and fresh environment for them to dwell on. Some organisms would be of big help to identify several conditions of the bodies of water.
Daphnia magna is commonly used a bio-toxicity indicator for water pollution. It used due its short doubling time, high sensitivity to heavy metals and simplicity. The mortality rate of Daphnia indicates that the water was polluted or not.
This study simply determined the mortality rate of Daphnia magna when exposed to water samples collected from Jalaud River, Bangga Bante, Iloilo. Water samples were collected from Jalaud River around three o’clock in the afternoon. The temperature, amount of dissolved oxygen and pH levels were measured on-site. Forty daphnia magna were added to each sample poured into a basin. Every 6 hours an observation was done, whether there is a change on the number of daphnia from the initial population. After 24-hour exposure, results showed that there is higher mortality rate obtained from the upstream than from the downstream water samples.
Using the PAST software, t-test method was used to know the significance of the data obtained. The results of the t-test showed that there was no significant difference on the upstream and downstream samples, same as well as to the temperature and amount of dissolved oxygen. Only the pH levels showed a significant difference among the parameters measured.