Impactos da ação humana sobre a ictiofauna do Rio Capibaribe : percepção, degradação e conservação

• Autor(a) principal: ALMEIDA, Carolina Alves Collier de
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4418
• topic: Poluição da água; Rio; Impacto antrópico; Ictiofauna; Pollution; River; Ichthyofauna; CIENCIAS BIOLOGICAS

Anthropogenic disturbances on aquatic ecosystems are related to the multiple uses of water and soil, being the agriculture and urbanization the most commonly observed impacts. These threats on the integrity of aquatic ecosystems has been increasingly recognized and associated with negative effects on the habitat, water quality and biota. With natural ecosystem degradations the environmental services are affected, causing economic and cultural problems. This scenario of degradation of aquatic ecosystems can be seen in the Capibaribe River Basin in northeastern Brazil. The Capibaribe has been suffering anthropogenic impacts since colonial period, being currently its banks dominated by monoculture of sugarcane and the urban-industrial development. The fishing activity is highlighted in the Capibaribe river basin, being these activities affected by the degradation of this river, affecting the income generation of fishermen and modified his view and relationship with the aquatic environment. In this context, the present study investigated the relationship between human impacts, fish fauna and the quality of the aquatic environment, as well as some of the consequences of environmental degradation for the riverine population. Thus, this thesis is divided into two chapters: the first aimed to understand a river degradation, and in particular its effects on the ecosystem and the local community; and the second aimed to understand the effects of human impacts in a river, assessing the relationship between assemblage of fish, environmental variables and predominant land use. In the first chapter the research was developed in Beira Rio community, in municipality São Lourenço da Mata (PE), inserted in a context of disorderly growth and without basic infrastructure, situated on the margins of the Capibaribe River. In this study geoprocessing techniques were employed to evaluate urban growth, and monitoring water data of the last two decades to assess changes in water quality. This research employed ethnobiological approaches, through interviews and participatory methods to retrieve information about the river environment, its fish fauna and their environmental services. According to the GIS analysis, can be observable an accelerated process of urbanization, with the urban area increasing from 73 383 565.98 m2 to 363.6 m2 in three decades. Informants perceived the urban growth, especially in the late twentieth century, with the transition of this century recognized as the period of greatest negative changes in the river environment. The perceived decline of fish stocks was appointed by the community as one of the effects of river degradation. Environmental data indicated that the river is suffering eutrophication, and has a fecal coliform concentrations 160 times higher than the maximum allowed by Brazilian law. The second chapter was developed along the lower stretch of the Capibaribe river, being monthly sampled the fish fauna and 20 environmental variables at five locations under different land uses. To collect the fish fauna were used gill nets and "berço", while the environmental variables were measured from the collection of water samples. The identification of the land uses was carried out from the vectorization of georeferenced satellite images being analyzed five classes of land use. Our results showed the influence of anthropogenic impacts in aquatic environment, revealing that the predominant land use affects the environmental variables as well as the assemblage of fish. The importance of the presence of forest buffers along the banks of water bodies was evident in this study, in which the reference environments showed the best environmental conditions, sustaining a more diverse and equitative fish fauna. The human impacts resulting from agriculture and urbanization promoted the simplification and the imbalance of the fish fauna, and promote the enrichment of nutrients in the aquatic ecosystem. These impacts were more pronounced in the urbanizated environment, suggesting that this land use has greater effects on the aquatic ecosystem. The interdisciplinary approach used in this study allowed us to understand the process of anthropogenic degradation in a river and some of its effects on water quality, fish fauna and the surrounding human population, revealing that integrate environmental data, GIS, fish fauna and the local human population allow a more holistic understanding of reality. This model approach enables the development of more effective plans to improve land use practices, the protection of aquatic ecosystems, the restoration of riparian areas, biodiversity conservation, as well as the inclusion of the adjacent human communities in this context.