Date of Award:

5-1-1981

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Biology

Department name when degree awarded

Life Sciences:Biology

Committee Chair(s)

Raymond I. Lynn

Committee

Raymond I. Lynn

Committee

John O. Evans

Committee

Charles W. Fowler

Committee

Vincent A. LaMarra

Committee

Donald A. Porcella

Committee

Fred W. Post

Abstract

The direct effects of simazine, an s-triazine herbicide, upon the green alga, Chlamydomonas reinhardii; and the invertebrate, Daphnia pulex, were studied by exposure of both organisms to different concentrations of simazine over long time periods. The effects of simazine upon growth and reproduction in Daphnia pulex were evaluated using both C. reinhardii and mixed bacterial culture as a food source. A simulation model was developed to assess the effects of simazine introduction into natural aquatic systems. Simazine in concentrations of 0.5ppm and above was shown to inhibit growth in cultures of C. reinhardii. Daphnia pulex reproduction and growth increased as simazine concentration increased when C. reinhardii was used as a food source. Reproduction was depressed at the higher levels of simazine when compared to controls without simazine when mixed bacterial cultures were used as food sources. Simulation results indicated that the introduction of simazine into natural aquatic systems could have adverse impacts upon overall productivity of the system if residence time of the herbicide was long.

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