Description

Fish and River Pollution deals with experimental and field research connected with the effects of pollution in fish, and the useful data gathered from these studies. After reviewing some experiments made on the effects of pollution on fish, the author discusses pollution by oxygen-reducing effluents such as sewage, milk washing, and other solutions that can be broken down by microorganisms, a process that uses up dissolved oxygen in the water. The experiments conducted by Shelford and Allee, which the author cites, studies the reactions of fish to different concentrations of atmospheric gases, particularly as fish detect low concentrations of oxygen more sensitively than man. The paper also discusses the time-effect relationship of a toxic substance to fish as immersion time, time needed for advancement, minimum time of exposure, and immersion time to fatality. The effect of thermal pollution such as that generated in thermal plants to produce electricity, though chemically toxic-free, can significantly change the temperature of the water where fish live. Such temperature change can affect water viscosity, rate of water oxygen absorption, development of sewage fungus, and changes in natural invertebrate fauna. This book can be appreciated by environmentalists, aquatic researchers, zoologists, and marine biologists.