Dodd, Jennifer Ann (2011) Long-term change in river invertebrate communities. PhD thesis. http://theses.gla.ac.uk/2959/ Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Glasgow Theses Service http://theses.gla.ac.uk/ [email protected] LONG-TERM CHANGE IN RIVER INVERTEBRATE COMMUNITIES JENNIFER ANN DODD THIS THESIS IS SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY SEPTEMBER 2011 i ABSTRACT Finding rules that govern species distribution and coexistence is a fundamental aim of ecological research. The rapidly expanding and increasingly mobile human race is challenging our understanding of some these rules. Using long-term macroinvertebrate data collected from two river systems with contrasting legacies from human activity, this thesis investigates drivers of change in community structure and function, mechanisms underpinning these changes and how these changes affect the accurate assessment of the ecological condition of river systems. The reformation of the river invertebrate communities within the River Clyde system was not predicted by the simple improving measures of water physico-chemistry or life history characteristics of the re-colonising community. This has serious implications for the accurate assessment of river health which is at present largely reliant on the physio- chemical tolerance of macroinvertebrates to indicate prevailing environmental conditions. It is argued that reference condition predictions, like those obtained from the RIVPACS programme, may not be suitable when assessing the ecological health of a river subjected to long-term modification from human activity, like the River Clyde. Significant differences in the stable isotope signatures of resident and colonising populations of Rhyacophila dorsalis (a predatory Trichopteran) provided insight into some mechanisms underlying differences between reforming communities. Trophic position estimates for some colonising populations of R. dorsalis were shown to be lower than expected considering their predatory status and, colonisation patterns were significant in predicting changes in occupied trophic position. The River Endrick is recognised internationally in terms of biodiversity. Over the last 50 years, the diversity of macroinvertebrate fauna of the river has significantly reduced, five species have become locally extinct and there has been a significant change in the distribution of 29 other species. The macroinvertebrate community in the headwater of the river has undergone a dramatic change in structure and function. The contrasting changes to the headwater community and changes in the structure and function of the macroinvertebrate community in the river system require further investigation. This thesis demonstrates the importance of investigating long-term change. ABSTRACT ii TOP 100 WORDS iii CONTENTS CHAPTER 1 General Introduction 1 1.1 Community ecology in a contemporary setting 1 1.2 Restoration ecology 2 1.3 Measuring ecological change 3 1.4 Bioindicators 4 1.5 Macroinvertebrates in running water 5 1.6 The importance of assessing long-term change 6 1.7 Quantifying long-term change 8 1.7.1 River Clyde history 8 1.7.2 River Clyde data set 11 1.7.3 River Endrick history 12 1.7.4 River Endrick data set 13 1.8 Overall aims and thesis structure 14 Spatial and temporal changes in aquatic CHAPTER 2 macroinvertebrate Families in the River Clyde 16 2.1 Introduction 16 2.2 Methods 17 2.2.1 Study area 17 2.2.2 Invertebrate community composition 18 2.2.3 Common macroinvertebrate Families in the River Clyde 18 2.2.4 Site characteristics 18 2.2.5 Spatial occurrence and temporal change 19 2.2.6 Temporal change associated with simple life characteristics 19 2.3 Results 20 2.3.1 Common macroinvertebrate Families in the River Clyde 20 2.3.2 Site characteristics PCA 20 2.3.3 Spatial occurrence and temporal change 20 2.3.4 Temporal change associate with simple life characteristics 22 2.4 Discussion 27 CHAPTER 3 Drivers of community diversity 31 3.1 Introduction 31 3.2 Methods 32 3.2.1 Study area 32 3.2.2 Invertebrate community composition 33 3.2.3 Site characteristics 33 3.2.3.1 Natural site characteristics 33 3.2.3.2 Land use characteristics 34 3.2.3.3 Physio-chemistry characteristics 34 3.2.4 Statistical methods 35 3.2.4.1 Environmental drivers of community richness 35 3.2.4.2 Temporal change 36 3.2.4.3 Univariate relationship with community richness 38 3.2.4.4 Community richness change within the River Clyde 38 3.3 Results 38 3.3.1 Environmental elements defined by PCA 38 3.3.1.1 Natural site variables PCA 38 3.3.1.2 Upstream land use variables PCA 39 3.3.2.2 Water physio-chemistry variables PCA 39 3.3.2 Environmental elements relationship with community richness 39 Temporal change in community richness and environmental 3.3.3 elements 40 CONTENTS iv 3.3.4 Univariate community richness relationships 40 3.3.4.1 Natural site characteristics 40 3.3.4.2 Upstream land use 41 3.3.4.3 Water physio-chemistry 41 3.3.5 Community richness change within the River Clyde 44 3.4 Discussion 44 3.4.1 Water physio-chemistry 45 3.4.2 Upstream land use 46 3.4.3 Natural site characteristics 47 3.4.4 Temporal change in community richness 48 Do shifting dynamics of disturbed riverine CHAPTER 4 invertebrate communities prevent them achieving a 'pristine' condition? 49 4.1 Introduction 49 4.2 Methods 50 4.2.1 Common macroinvertebrate Families in the River Clyde 51 4.2.2 Definition of site recovery 51 4.2.3 Site community composition in 2006 52 4.2.4 'Target' community composition 52 4.2.5 Comparison of community composition 53 4.3 Results 53 4.3.1 Common macroinvertebrate Families in the River Clyde 53 4.3.2 Definition of site recovery 53 4.3.4 Site community composition in 2006 55 4.3.5 'Target' community composition 55 4.3.6 Comparison of community composition 55 4.4 Discussion 56 Resource use of an invading predator is predicted CHAPTER 5 by colonisation patterns 59 5.1 Introduction 59 5.2 Methods 61 5.2.1 Study area and site selection 61 5.2.2 Colonisation patterns 61 5.2.3 Stable isotope analysis 63 5.2.4 Isotopic baseline corrections 64 5.2.5 Statistical analysis 65 5.3 Results 66 5.3.1 Colonisation patterns 66 5.3.2 Organisms 68 5.3.3 Isotopic baseline corrections 68 5.3.4 Statistical analysis 69 5.3.4.1 Colonising and resident population differences 69 5.3.4.2 Colonisation patterns and trophic position 70 5.3.4.3 Colonisation patterns and carbon range 72 5.4 Discussion 73 Long-term change to species distribution on the CHAPTER 6 River Endrick 77 6.1 Introduction 77 6.2 Methods 78 6.2.1 Study area 78 6.2.2 Historic studies of the River Endrick fauna 78 6.2.2.1 1960 study 79 6.2.2.2 1990 study 79 CONTENTS v 6.2.3 2010 study 79 6.2.3.1 Site selection 79 6.2.3.2 2010 sample collection 80 6.2.4 Species abundance and distribution 81 6.2.4.1 Occupied site changes 82 6.2.4.2 Site abundance 82 6.2.4.3 Frequency of occurrence 82 6.2.5 Distribution analysis 84 6.2.6 Statistical analysis 84 6.3 Results 86 6.3.1 Invertebrata 87 6.3.1.1 Tricladida 88 6.3.1.2 Hirudinea 91 6.3.1.3 Crustacea 95 6.3.1.4 Ephemeroptera 98 6.3.1.5 Plecoptera 106 6.3.1.6 Hemiptera 119 6.3.1.7 Trichoptera 120 6.3.1.8 Coleoptera 127 6.4 Discussion 130 6.4.1 Local extinctions 131 6.4.2 New species 132 6.4.3 Range extensions 132 6.4.4 Range contractions 134 6.4.5 Range changes 134 6.4.6 Abundance changes 135 6.5 Conclusions 136 Diversity and community function change in a river CHAPTER 7 with a legacy of minimal human influence 138 7.1 Introduction 138 7.2 Methods 139 7.2.1 Study area 139 7.2.3 River Endrick community structure 139 7.2.4 Changes in community structure 140 7.2.5 River Enrick community function 141 7.2.5.1 Functional feeding abundance 142 7.2.5.2 Saprobic abundance 142 7.2.5.3 Flow and temperature preference 143 7.2.6 Changes in community function 144 7.2.7 Statistical analysis 145 7.3 Results 145 7.3.1 Community structure changes 145 7.3.2 Community function changes 147 7.3.2.1 Functional feeding abundance 147 7.3.2.2 Saprobic abundance 150 7.3.2.3 Flow and temperature preference 152 7.4 Discussion 154 7.4.1 Headwaters 154 7.4.2 Upper reaches 155 7.4.3 Middle reaches 156 7.4.4 Lower reaches 157 7.5 Conclusions 158 CHAPTER 8 General Discussion 159 8.1 Future Work 162 CONTENTS vi Overview of the land use and solid geology of the two APPENDIX A river systems (River Clyde and River Endrick) and the location of the sampling sites used in this study 164 Species of Tricladida, Hirudinea, Megaloptera, Ephemeroptera, Plecoptera, Hemiptera, Neuroptera, APPENDIX B Trichoptera, Lepidoptera and coleoptera recorded in the 1960 and 2010 study periods 167 Species with similar distribution on the River Endrick in APPENDIX C the 1960 and 2010 study periods 172 Keys used in the identification of the macroinvertebrate APPENDIX D species from the River Endrick 222 REFERENCES 225 CONTENTS vii LIST OF TABLES Table Title Page Recorded site frequency (65 site in total) for the 42 common Families, revised BMWP scores and coefficients and significance values from the associated logistic regressions.