Pak. J. Bot., 43(4): 2067-2069, 2011. | Back to Contents | ||||
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Updated: 20-08-11 | ||||
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TOXICITY OF PESTICIDES ON PHOTOSYNTHESIS OF DIATOMS
Abstract: Pakistan being an
agricultural country, a large amount of pesticides are used, including
organophosphates and synthetic pyrethroids. These pesticides are
released through rivers and other tributeries into the coastal
environment, thus posing a contiuous threat to marine organisms. In
the present study two species of diatoms Amphora and
Navicula were selected for the assessment of impact of
organphosphate and pyrethroid toxicity on these primary producers. The
study shows that rate of photosynthesis was inhibited in both
Amphora and Navicula species exposed to pesticide. The
acute toxicity of pesticide was determined by measuring IC50 of the
test organisms. IC50 calculated for diatom species depicts that
different pesticides had variable effects on the photosynthesis of
microalgae. High sensitivity of marine organisms is alarming as it
may have implications on the marine ecosystem and fisheries. The
results are also useful in setting control limits for the release of
these chemicals in nature. Centre of Excellence in Marine Biology, University of Karachi, Karachi-75270, Pakistan *Corresponding author e-mail: Jamal.siddiqui@yahoo.com |
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