Eutrofització dels rius d'Andorra Authors Narcís Prat Maria Àngels Puig Maria-Isabel Bautista Gloria González Peña Abstract An analysis of the phosphorus increase in the watersheds of Andorra as a result of the increase of human population in the river banks is made. The greater concentrations in phosphorus are found in relation to the increase of population and also in some sampling stations in the highlands of this country. In high altitude the phosphorus concentrations are related to hotel and sport facilities. Also the influence of water catchements to power works are analized. In August the major stream, the Valira river, is dried in this catchement process in station 22 and until the time of return of water (station 14) the main river receives only wastewaters of two villages and water of minor tributaires. This means a great increase in the phosphorus concentration in waters in stations 15 and 16 (figs. 1 and 2). A modification in the composition of animal communities can be stated examining the macrofauna, especially insects, of river stones. There is a relationship between phosphorus concentration and the modification of communities. As a result of human population increase the lower part of Andorra is higly enriched in nutrients in August, especially in phosporus. A great quantity of phosphorus, estimated between 4 and 8 MT/month, leaves the Valira river in the sampling station 1. Downloads Download data is not yet available. Downloads Text complet (Català) Published 2005-05-17 Issue Vol. 45 : 1980 (Secció de Zoologia, 3) Section Articles License The intellectual property of articles belongs to the respective authors.On submitting articles for publication to the journal Butlletí de la Institució Catalana d'Història Natural authors accept the following terms:Authors assign to Institució de la Societat Catalana d’Història Natural (a subsidiary of Institut d’Estudis Catalans) the rights of reproduction, communication to the public and distribution of the articles submitted for publication to Butlletí de la Institució Catalana d'Història Natural.Authors answer to Institució de la Societat Catalana d’Història Natural for the authorship and originality of submitted articles.Authors are responsible for obtaining permission for the reproduction of all graphic material included in articles.Institució de la Societat Catalana d’Història Natural declines all liability for the possible infringement of intellectual property rights by authors.The contents published in the journal, unless otherwise stated in the text or in the graphic material, are subject to a Creative Commons Attribution-NonCommercial-NoDerivs (by-nc-nd) 3.0 Spain licence, the complete text of which may be found at https://creativecommons.org/licenses/by-nc-nd/3.0/es/deed.en. Consequently, the general public is authorised to reproduce, distribute and communicate the work, provided that its authorship and the body publishing it are acknowledged, and that no commercial use and no derivative works are made of it.The journal Butlletí de la Institució Catalana d'Història Natural is not responsible for the ideas and opinions expressed by the authors of the published articles.