Effects of aquatic pollution by a non-ionogenic surfactant on the marine diatom Thalassiosira pseudonana

The effects of the non-ionogenic surfactant, Triton X-100 (TX), on the growth of cultured centric diatom Thalassiosira pseudonana were studied. In the presence of 0.1 mg/l TX the cell density in the culture was markedly lower than in the control culture. In the presence of 1 mg/l TX the decrease in cell density exceeded 50%. The decrease in the specific growth rate was about 10% in the presence of 0.1 mg/l TX and about 40% in the presence of 1 mg/l TX (over a period of seven days). The diatom sensitivity to TX was higher than that of some red and green algae and chrysophytes, as well as that of starfish spermatozoa and plant seedlings to TX or similar surfactants. These data reveal some more aspects of the ecological danger of aquatic pollution by non-ionogenic surfactants.