Resilience to land use induced impacts. A contribution to improve precautionary ecological management in coastal ecosystems Zara Fani Gonçalves Teixeira Setembro 2015 Tese de Doutoramento em Biociências, na especialidade de Ecologia, orientada pelo Professor Doutor João Carlos Marques e apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra This thesis was supported by: Fundação para a Ciência e Tecnologia (FCT) PhD grant attributed to Zara Teixeira SFRH / BD / 74804 / 2010 MARE-UC – Marine and Environmental Sciences Centre University of Coimbra, Portugal Department of Life Sciences, Faculty of Sciences and Technology (FCTUC) University of Coimbra, Portugal Dedicada às mulheres da minha vida e ao meu caçula Contents Abstract .......................................................................................................................................... 1 Resumo .......................................................................................................................................... 5 General introduction ...................................................................................................................... 9 Integrated river basin management............................................................................................. 9 DPSIR framework ....................................................................................................................... 11 The role of land cover ................................................................................................................ 13 The Mondego river basin ........................................................................................................... 14 The Mondego estuary................................................................................................................ 15 General aims and thesis outline ................................................................................................... 17 Publications .................................................................................................................................. 19 Chapter I ....................................................................................................................................... 21 Abstract ..................................................................................................................................... 22 Introduction .............................................................................................................................. 23 Methodology ............................................................................................................................. 27 Results ....................................................................................................................................... 29 Discussion.................................................................................................................................. 40 Conclusion ................................................................................................................................. 43 Chapter II ...................................................................................................................................... 45 Abstract ..................................................................................................................................... 46 Introduction .............................................................................................................................. 47 Methodology ............................................................................................................................. 49 Results ....................................................................................................................................... 60 Discussion.................................................................................................................................. 67 Conclusion ................................................................................................................................. 72 Chapter III ..................................................................................................................................... 73 Abstract ..................................................................................................................................... 74 Introduction .............................................................................................................................. 75 Methodology ............................................................................................................................. 77 Results ....................................................................................................................................... 82 Discussion.................................................................................................................................. 95 Conclusion ............................................................................................................................... 101 Chapter IV................................................................................................................................... 103 Abstract ................................................................................................................................... 104 Introduction ............................................................................................................................ 105 Methodology ........................................................................................................................... 110 Results ..................................................................................................................................... 113 Discussion................................................................................................................................ 116 Conclusion ............................................................................................................................... 121 Contents V General discussion...................................................................................................................... 123 The use of indicators and the role of land cover ...................................................................... 123 Assessing progress ............................................................................................................... 123 Effectiveness of measures .................................................................................................... 124 Assessing pressure and driving forces from land cover maps ............................................... 126 The Mondego system in the European context ........................................................................ 128 References .................................................................................................................................. 133 Agradecimentos/Acknowledgments .......................................................................................... 149 Appendix .................................................................................................................................... 153 VI Abstract The European Water Framework Directive enhances the role of land use in determining water quality of all waters, but the use of land cover data, regarding surface waters, is restricted to the estimation of land use patterns for the identification of pressures on surface waters from diffuse source pollution. The main goal of this study is to uncover specificities of land cover in the assessment of state changes (Chapter I), pressures (Chapter I and II) and drivers (Chapter III and IV) of water quality of surface waters. For this purpose, we use data from the Mondego river basin, a coastal watershed in Portugal, where socio-economic changes observed since the 1990s resulted in the loss of representativeness from the agricultural sector and gain from the construction sector. Despite the observed changes, agriculture remained a source of pressure on surface waters which, associated with hydro-morphological modifications, caused a decline of the ecological quality of the Mondego estuary. In 1998, the implementation of mitigation measures enabled the recovery of the system but routine monitoring identified high concentrations of nutrients deserving further assessment to understand its sources. For this reason, the Mondego river basin, as a case study, provided conditions to reveal wider applications of land cover data within the assessment of drivers and pressures of water quality. Chapter I establishes the baseline for our research applying indicators of nutrients and oxygen- consuming-substances to analyze progress in the concentrations of ammonia, nitrate and phosphate in the Mondego estuary from a former period (2003-2007) to a recent period (2012- Abstract 1 2013) (ANOVA in R software); to analyze differences between the annual mean concentrations of nutrients in the tributary rivers in 2012-2013 and the average annual mean concentrations found in European rivers in three different periods (1992, 2000, 2012); and to evaluate differences in the variability of nutrient concentrations between the estuary and the tributaries in 2012-2013 (ANOVA in R software). Additionally, Chapter I evaluates the dependency of estuarine nutrient concentrations