Inhibition of photosynthesis and respiration by chlorinated hydrocarbons in some marine algae

Abstract

The effect of low concentration (50 ppb) of three chlorinated hydrocarbons p,p'-DDT, lindane and endosulfan on photosynthesis and respiration of some common benthic marine macro algae, viz. Gracilaria verrucosa, Grateloupia sp. Enteromorpha intestinalis and Cheatomorpha linum was studied. The toxic effect of chlorinated hydrocarbons differ widely for each species of algae, while E. intestinalis was less tolerant to lindane, Grateloupia sp. was less tolerant to DDT. G. verrucosa showed relatively less tolerance to all the three pesticides. Among the three pesticides endosulfan is less toxic than DDT and lindane. The effect of these chlorinated hydrocarbons on the net carbon assimilation and photosynthesis to respiration ratio are also reported