Abstract: “The accumulation of pesticides in the environment poses a major health concern to humans, plants and animals, thus the presence of these toxicants require close monitoring. Bioindicators such as green algae are widely researched for the detection of toxicants or pollutants and has been reported to have more advantages compared to the conventional detection methods. The objective of this study is to determine the response of carotenoids and chlorophyll in Spirogyra as a potential bioindicator in pesticides detection. Cells immobilized using agarose gel were exposed to 0.001 mg/L, 0.010 mg/L, 0.100 mg/L, 1.000 mg/L and 10.000 mg/L of 2,4-dichlorophenoacetic acid (2, 4-D) and atrazine for a period of 48 hours. Respond trends for chlorophyll and carotenoids were recorded. Carotenoids showed higher potential as the marker for 2,4-D detection while chlorophyll was the better one in atrazine detection”

Keywords: Chlorophyll, carotenoids, pesticides bioindicator, Spirogyra