The work described in this series of reports is part of the Joint Government-Industry Fact Finding Study carried out in the 'Uranium Province' of the Alligator Rivers Area, Northern Territory, during 1971—73. The primary objective was to determine the sensitivity of the existing environment to the range of potential pollutants arising from a uranium extractive industry. A comprehensive ichthyography is given of species collected in the area. Results are reported of experimental and bioassay studies on selected flora and fauna exposed to heavy metals, raffinate and Alamine-336. Studies are also recorded on the chemical and radiological qualities of natural waters, the solubility of uranium in sediments, and the fate of dissolved trace elements in the drainage systems. The radiological aspects of the area are discussed with specific reference to exposure routes, bit ogical concentration factors, and the significance of natural and man made changes in levels of radiation to man and other biota in the region. Radon levels in costeans, core-sheds and bore water are recorded and discussed.