Autor(es):
Capela, Joana Rebelo 
Data: 2008
Identificador Persistente: http://hdl.handle.net/10451/1373
Origem: Repositório da Universidade de Lisboa
Assunto(s): Ecologia; Gestão da água; Biodiversidade; Barragens; Teses de mestrado
Descrição
Tese de mestrado, Biologia (Ecologia e Gestão Ambiental), 2007, Universidade de Lisboa, Faculdade de Ciências Water Framework Directive is an important tool in the management of European surface waters, namely for heavily modified water bodies that remain poorly assessed. The objective of this study was to establish a fish based methodology to assess the ecological potential of Spanish reservoirs. Specifically an abiotic typology was developed and metrics commonly used in indices of biotic integrity worldwide were evaluated for application in different fish-ecoregions. A total of 120 reservoirs in the Guadiana, Júcar, Douro and Northern basins were characterized using 9 hidromorphological variables. Main descriptors of reservoir variability were identified using Principal Component Analysis, and Ward's clustering helped in the construction of an abiotic typology scheme, that proved to be more effective than traditional System A applications. Overall, 14 reservoir types were established based in catchment area, altitude, volume and geology. Fish in 88 reservoirs in the Jucar, Douro and Northern basins were assigned into functional guilds and 100 metrics were tested for range, responsiveness, redundancy and precision. River basins were considered as distinct eco-regions based on Ward clustering of low-impacted sites and Kruskal-Wallis tests. Water quality and human impacts in each reservoir were approached using 4 environmental variables. Overall, 13 candidate metrics were responsive to turbidity and integrated chlorophyll a. However, there was considerable variation among basins in the set of selected metrics, with only density of phytophilic and tolerant species being common to all regions. Moreover, metrics showed no significant variation between low-impacted and impacted reservoirs. Despite being preliminary, current results highlight the complexity of reservoir dynamics, and suggest that progress in ecological assessment of heavily modified water bodies will dependent on the development of new typology schemes and fish metrics specifically targeted at these systems Resumo alargado em português disponível no documento
Tipo de Documento
Dissertação de Mestrado
Orientador(es)
Magalhães, Maria Filomena; García-Amilibia, Miguel Alonso
