Da ecologia experimental a ações para conservação de rios.

Abstract

Ecology is a very broad science. The current ecologist must be attentive not only to conduct research and collaborate with the advancement of science, but also to find ways to popularize science and transform scientific knowledge into something that can be easily interpreted and potentially benefits majorities. In this way this thesis is divided into two topics, one that reports results of a scientific research and one that reports a case study that is the result of popularization of science. In the first chapter, interactions between eye-flukes and the behavior of their hosts were studied. It has been experimentally observed that eye parasites exert strong influence on the anti-predator behavior of cichlid Satanoperca pappaterra when occupy the region where the incoming light is potentially blocked. In addition, parasites tend to migrate to this region under light stimulation, when water birds forage intensely. Thus, this parasite behavior becomes intermediate hosts more exposed to predation of birds, the target hosts. These results suggest that the adaptive behavior of parasite manipulates the anti-predator response of fish and increases the probability of completing life cycle. The second chapter presents a case study of prevention of dams on two important tributaries of the Paraná river, Brazil. A joint action between the University and the Prosecution aimed on aware local societies about the consequences of new dams, that resulted in effective actions to prevent dams. The most significant outcome was the enactment of municipal laws that protect certain areas of the basins and the process of registration of features of rivers as heritage, which sets partial protection of the rivers. Thus, this thesis addresses both the academic requirements to disclose innovative scientific results, as provides a tool to conserve high conservation priority rivers that is liable of being applied throughout the Brazilian territory.