Water Quality Criteria for European Freshwater Fish

Download or read book Water Quality Criteria for European Freshwater Fish written by European Inland Fisheries Advisory Commission. Working Party on Water Quality Criteria for European Freshwater Fish and published by Australian Geographic. This book was released on 1987 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: For water pollution control purposes, the concentration-addition model for describing the joint effects of mixtures of toxicants on aquatic organisms is appropriate; in this model the contribution of each component in the mixture is expressed as a proportion of the aqueous concentration producing a given response in a given time. Examination of available data using this model shows that for mixtures of toxicants found in sewage and industrial effluents, the joint acutely-lethal toxicity to fish and other aquatic organisms is close to that predicted assuming simple addition of the proportional contribution from each toxicant. The observed median value for the joint effect of these toxicants on fish is 0.95 of that predicted, and the corresponding collective value for sewage effluents, river waters, and a few industrial wastes, based on the toxicity of their constituents, is 0.85, while that for pesticides is 1.3. The less-than-additive effect of commonly-occurring toxicants in some mixtures may be partly attributable to small fractions of their respective LC50 values having little or no additional effect.