Universidad de Concepción Dirección de Postgrado Facultad de Ciencias Ambientales, Programa de Doctorado en Ciencias Ambientales EFECTOS DE LA REDUCCIÓN DEL CAUDAL POR ACTIVIDADES AGRÍCOLAS EN RÍOS DE LA ZONA MEDITERRÁNEA DE CHILE Tesis presentada para optar al grado de: Doctor en Ciencias Ambientales, mención en Sistemas Acuáticos Continentales MEYER EDUARDO GUEVARA MORA CONCEPCIÓN-CHILE 2015 Dr. Ricardo Figueroa Jara Tutor Departamento de Sistemas Acuáticos Facultad de Ciencias Ambientales Universidad de Concepción Universidad de Concepción Dirección de Postgrado Facultad de Ciencias Ambientales Programa de Doctorado en Ciencias Ambientales Comisión evaluadora de tesis de grado: Dr. Ricardo Figueroa Jara (Tutor) Dr. Roberto Urrutia Pérez Facultad de Ciencias Ambientales Facultad de Ciencias Ambientales Universidad de Concepción Universidad de Concepción Dr. José Luis Arumi Ribera Dra. María Luisa Suárez Alonso Facultad de Ingeniería Agrícola Departamento de Ecología e Hidrología Departamento de Recursos Hídricos Universidad de Murcia Universidad de Concepción ÍNDICE GENERAL ÍNDICE GENERAL .................................................................................................... I ÍNDICE DE TABLAS .............................................................................................. IV ÍNDICE DE FIGURAS ............................................................................................ VI AGRADECIMIENTOS ......................................................................................... VIII RESUMEN ................................................................................................................. 1 INTRODUCCIÓN ...................................................................................................... 2 Impactos de la reducción de caudal en los sistemas fluviales ....................... 3 Utilización de bioindicadores para la estimación de los impactos de la reducción de caudal............................................................................ 6 HIPOTESIS ................................................................................................................ 8 OBJETIVOS ............................................................................................................... 9 Objetivo general ............................................................................................. 9 Objetivos específicos ...................................................................................... 9 METODOLOGÍA ..................................................................................................... 10 Área de estudio ............................................................................................. 10 Recolección de información bibliográfica y diseño de muestreo ................. 12 BIBLIOGRAFÍA ...................................................................................................... 13 CHAPTER 1. EFFECTS OF IRRIGATION WATER WITHDRAWALS IN MEDITERRANEAN LOW ORDER RIVERS OF CHILE: A REVIEW ... 19 RESUMEN ............................................................................................................... 19 ABSTRACT ............................................................................................................. 20 INTRODUCTION .................................................................................................... 20 Characteristics of the Chilean water market and the relation with the fluvial ecosystem .......................................................................................... 22 Changes in the fluvial ecosystems by water withdrawals............................. 26 Macroinvertebrates community assemblage ................................................ 27 Biomonitoring low flow impacts with macroinvertebrates........................... 29 CONCLUSIONS ...................................................................................................... 31 ACKNOWLEDGMENTS ........................................................................................ 31 REFERENCES ......................................................................................................... 32 CHAPTER 2. FRESHWATER BIODIVERSITY CONSERVATION IN MEDITERRANEAN CLIMATE STREAMS OF CHILE ........................... 39 ABSTRACT ............................................................................................................. 39 I INTRODUCTION .................................................................................................... 40 Biogeography ............................................................................................... 43 CURRENT STATUS OF FRESHWATER BIODIVERSITY KNOWLEDGE ...... 45 Diatoms and Macrophytes ............................................................................ 46 Aquatic insects .............................................................................................. 47 Other invertebrates ....................................................................................... 55 VERTEBRATES ...................................................................................................... 57 Amphibians ................................................................................................... 57 Fish…… ........................................................................................................ 57 CONSERVATION AND FUTURE CHALLENGES .............................................. 58 Projected Climate Change............................................................................ 58 Pollution and pressures ................................................................................ 60 CONCLUSIONS ...................................................................................................... 62 ACKNOWLEDGEMENTS ..................................................................................... 64 REFERENCES ......................................................................................................... 64 CHAPTER 3. EFFECTS OF WATER WITHDRAWALS BY AGRICULTURAL ACTIVITIES IN THE FLUVIAL HABITAT OF BENTHIC MACROINVERTEBRATES OF CENTRAL CHILE ................................. 73 ABSTRACT ............................................................................................................. 73 INTRODUCTION .................................................................................................... 74 METHODS ............................................................................................................... 75 Characteristics of the sampling sites ............................................................ 75 Habitat sampling strategy ............................................................................ 76 Macroinvertebrate sampling ........................................................................ 76 Data analysis ................................................................................................ 77 RESULTS ................................................................................................................. 78 DISCUSSION ........................................................................................................... 83 ACKNOWLEDGMENTS ........................................................................................ 86 REFERENCES ......................................................................................................... 86 CHAPTER 4. INFLUENCE OF THE WATER ABSTRACTION IN THE MACROINVERTEBRATE TRAITS OF MEDITERRANEAN LOW ORDERS OF CHILE. .................................................................................. 91 INTRODUCCIÓN .................................................................................................... 91 METHODOLOGY ................................................................................................... 92 Sampling sites ............................................................................................... 92 II Sampling design ............................................................................................ 93 Invertebrate sampling ................................................................................... 93 Data analysis ................................................................................................ 94 RESULTS ................................................................................................................. 96 DISCUSIÓN ........................................................................................................... 101 ACKNOWLEDGMENTS ...................................................................................... 104 REFERENCES ....................................................................................................... 104 DISCUSIÓN GENERAL ....................................................................................... 108 CONCLUSIONES .................................................................................................. 114 BIBLIOGRAFÍA .................................................................................................... 116 III ÍNDICE DE TABLAS Table 1. Water withdrawals (L/s) in different sites of the Itata basin (October, December 2012, March 2013). .............................................................................................................. 26 Table 2. Principal biological indicators (macroinvertebrates) related to natural and anthropogenic low flow condition .......................................................................................