Abstract
In the present work a limnological evaluation was made with special emphasis on the effect of concentration of pesticides on fish and sediments in tradicional rice crops areas near of the rivers Ariari, Guayuriba, Humea and Meta in the Orinoco Basin (Llanos Orientales). The sampling areas showed interesting physicochemical characteristis wich magnify the effect of pesticides upon the biotic comunities. Based on these parameters and the biotic differences e dueto diversity and richness of species ), the area was grouped into two sub-systems, one of wich presented increaing signs of eutrofication. · The information recorder sic e 1980 shows that the fish comunities present preocupating hazardous in crease ofpesticide specially aldrin-dieldrin and metilparation in concentrations wich exceed those stablished by FAO/OMS.Univ. Sci. is registered under a Creative Commons Attribution 4.0 International Public License. Thus, this work may be reproduced, distributed, and publicly shared in digital format, as long as the names of the authors and Pontificia Universidad Javeriana are acknowledged. Others are allowed to quote, adapt, transform, auto-archive, republish, and create based on this material, for any purpose (even commercial ones), provided the authorship is duly acknowledged, a link to the original work is provided, and it is specified if changes have been made. Pontificia Universidad Javeriana does not hold the rights of published works and the authors are solely responsible for the contents of their works; they keep the moral, intellectual, privacy, and publicity rights. Approving the intervention of the work (review, copy-editing, translation, layout) and the following outreach, are granted through an use license and not through an assignment of rights. This means the journal and Pontificia Universidad Javeriana cannot be held responsible for any ethical malpractice by the authors. As a consequence of the protection granted by the use license, the journal is not required to publish recantations or modify information already published, unless the errata stems from the editorial management process. Publishing contents in this journal does not generate royalties for contributors.