Toxic Fresh-water Algae

Abstract

stems from a growing appreciation of the strictly scientific and biological problems involving the physiology of algae, especially those which produce toxic substances (possibly toxins), antibiotics, and growth-stimulating excretions. The present paper is intended as a contribution toward a summary of our present knowledge of toxic fresh-water algae. Especially it is predicated on interest that was aroused in the presentation of a lecture 'by the senior author, Organisms Encountered in Water Supplies. This was presented to classes in Advanced Sanitary Engineering Training in Water Pollution Investigations, and in Advanced Training for Bacteriologists Concerned with Water Analysis conducted at the Environmental Health Center, Public Health Service, Cincinnati, Ohio. Herein, we shall outline in a general way the effects of toxic fresh-water algae on man, domestic animals, and fish for especially those workers who are concerned with water pollution control programs. Thorough quantitative data are not available on toxic fresh-water algae as they are related to illness or death among fish and higher forms of life. It is the hope of the authors that through such a discussion of toxic algae more quantitative data will be brought into the literature from those who are concerned with water supplies as they may relate to man, domestic animals, and to fish and game. Only additional data on specific cases of poisoning by particular algae can present a comprehensive picture for the United States, thus permitting such information to be analyzed critically in the future. The algae that have been reported as causing death and, or, illness in mammals, birds, and fish through toxic action are, as far as we know, the bluegreens, Cyanophyta. The Cyanophyta can be differentiated from other groups of algae primarily by the fact that their pigments are not contained in chromatophores (pigment bodies). Unlike all other algae the pigments are in solution and are more or less confined to the peripheral portion of the protoplast. Included are chlorophyll-a, carotenes, distinctive xanthophylls, a blue pigment, c-phycocyanin, and a red pigment-c-phycoerythrin. The blue-green algae possess a primitive type of nucleus, the central body, which lacks a nuclear membrane and a nucleolus, in which respect they are similar to bacteria. The genera of the Cyanophyta that appear to possess toxic species are: Microcystis (figs. 1-4),* Anabaena (fig. 7), Aplianizomenon (figs. 5-6) Nod