THE UNIVERSITY OF LINCOLN The behaviour and ecology of adult common bream Abramis brama (L.) in a heavily modified lowland river A Thesis submitted for the Degree of Doctor of Philosophy By Christopher John Gardner B.Sc. (Hons) September 2013 1 CONTENTS Publications and outputs 5 List of tables 6 List of figures 7 Acknowledgements 12 Abstract 13 1. Rivers, fish and human interventions 15 1.1 General introduction 15 1.2 Objectives 17 1.3 A ‘natural’ lowland riverine ecosystem 17 1.4 Anthropogenic impacts on lowland riverine ecosystems 18 1.5 Fish ecology and rivers 21 1.6 Common bream ecology 23 1.7 Studying spatio-temporal behaviour of fishes with telemetry techniques 29 1.8 Proposed study 33 2. The ecology of the lower River Witham 35 2.1 Objectives 35 2.2 The lower River Witham 35 2.2.1 Background 35 2.2.2 History 36 2.2.3 Catchment and land use 39 2.2.4 Water quality 39 2.2.5 Biological quality 40 2.2.6 Flow regime and flood events 41 2.2.7 Water level management 43 2.2.8 Trent-Witham-Ancholme water transfer scheme 43 2.2.9 Morphology 43 2.2.10 Habitat assessments 45 2.2.11 Barriers to fish migration 49 2.2.12 River uses 49 2.2.13 Conservation 49 2.2.14 Fishery assessments 50 2.2.15 Water Framework Directive classification 57 2.3 Discussion 57 2.3.1 Water quality 57 2.3.2 Biological quality 58 2.3.3 Habitat assessments 58 2.3.4 Fishery assessments 58 3. The effects of surgical implantation of a telemetry transmitter into the peritoneal cavity and translocation on the temporal- spatial behaviour of common bream 61 3.1 Introduction 61 2 3.2 Material and methods 62 3.2.1 Study area 62 3.2.2 Sampling procedures 62 3.2.3 Tag implantation protocol 69 3.2.4 Tracking 76 3.2.5 Recapture and translocation 76 3.2.6 Data handling and statistical analysis. 78 3.3 Results 79 3.3.1 Recaptured fish 80 3.3.2 Effects of tagging procedure 82 3.3.3 Effects of translocation 83 3.4 Discussion 86 3.4.1 Tagging protocol 86 3.4.2 Recaptured fish 88 3.4.3 Shoaling behaviour 89 3.4.4 Fish that left the study area 89 3.4.5 Effects of tagging procedure 90 3.4.6 Effects of translocation 90 3.4.7 Possible experimental bias 91 4. Seasonal movements with shifts in lateral and longitudinal habitat use 93 4.1 Introduction 93 4.2 Material and methods 93 4.2.1 Study area 93 4.2.2 Sampling and tagging procedures 95 4.2.3 Environmental data 96 4.2.4 Data handling 96 4.2.5 Statistical analysis 97 4.3 Results 97 4.3.1 Monthly distance and monthly longitudinal distribution 97 4.3.2 Use of lateral habitat 100 4.4 Discussion 101 4.4.1 Monthly distance and monthly longitudinal distribution 101 4.4.2 Use of lateral habitat 106 5. Seasonal water level manipulations for flood risk management influences home-range size 109 5.1 Introduction 109 5.2 Material and methods 110 5.2.1 Study area 110 5.2.2 Sampling and tagging procedures 111 5.2.3 Data handling and statistical analysis 111 5.3 Results 114 5.3.1Effect of artificial water level manipulations 114 5.4 Discussion 118 5.4.1 Home-range size 118 5.4.2 Effect of artificial water level manipulations 118 6. Social networks in common bream 121 6.1 Introduction 121 6.2 Material and methods 125 3 6.3 Data handling and statistical analysis 125 6.4 Results 127 6.5 Discussion 132 7. Conclusions, management implications and further research 134 7.1 Rehabilitation of lowland rivers 134 7.2 Conclusions 135 7.2.1 Review of rivers, fish, human interventions, telemetry and common bream 135 7.2.2 The ecology of the lower River Witham 135 7.2.3 Effects of tagging and translocation 136 7.2.4 Seasonal movements and shifts in habitat use 136 7.2.5 Home-range size and the effects of artificial water level manipulations 138 7.2.6 Social networks 139 7.3 Recommendations for further research 139 References 141 4 Publications and outputs Scientific Papers Gardner, C.J., Deeming, D.C. & Eady, P.E. (2013) Seasonal movements with shifts in lateral and longitudinal habitat use by common bream Abramis brama (L.) in a heavily modified lowland river. Fisheries Management and Ecology 20, 315-325. doi: 10.1111/fme.12014 Gardner, C.J., Deeming, D.C. & Eady, P.E. (2013) Seasonal water level manipulation for flood risk management influences home-range size of common bream Abramis brama L. in a lowland river. Rivers Research and Applications, doi: 10.1002/rra.2727 Gardner, C.J., Deeming, D.C., Eady, P.E. & Wellby, I. (in prep) The effects of surgical implantation of a telemetry transmitter into the peritoneal cavity and translocation on the spatio- temporal behaviour of common bream. Fisheries Research, Conference proceedings Gardner, C.J. (2009) Using acoustic telemetry to target improvements to the lower River Witham, Lincolnshire. Proceedings of the 40th Institute of Fisheries Management Conference (eds: Dolben, I. & Axford, S.) 99-104 pp. Presentations Gardner, C.J. (2006) Bream Tracking in the River Witham. Environment Agency Anglian Region Fisheries Science Symposium. Gardner, C.J. (2007) Bream Tracking in the River Witham. Environment Agency Anglian Region Fisheries Science Symposium. Gardner, C.J. (2008) Bream Tracking in the River Witham. Grantham Angling Association Annual General Meeting. Gardner, C.J. (2008) Bream Tracking in the River Witham. Environment Agency National Fisheries Science Symposium. Gardner, C.J. (2008) Bream Tracking in the River Witham. Post-graduate showcase, Lincoln University. Gardner, C.J. (2009) Lower River Witham Water Level Management; Attempting Regime Change. Environment Agency Fisheries Science Symposium. Gardner, C.J. (2009) Bream Tracking in the River Witham. Lincoln University. Gardner, C.J. (2009) Using Acoustic Telemetry to Target Improvements to the Lower River Witham, Lincolnshire. Institute of Fisheries Management Conference. Gardner, C.J. (2010) Using Acoustic Telemetry to Target Improvements to the Lower River Witham, Lincolnshire. Environment Agency area management team. Conference posters Gardner, C.J. (2009) Bream Tracking in the River Witham. Institute of Fisheries Management Conference. Press articles Gardner, C.J. (2009) Bream Tracking in the River Witham. ‘Carp and Coarse Angler’ Magazine, Mpress Ltd. Romford. Gardner, C. J. (2010) Bream Tracking in the River Witham. Institute of Fisheries Management ‘Fish’ Magazine, IFM Nottingham. 5 List of tables Page Table 1.1 Fishes of modified European floodplain rivers have been classified into guilds by their habitat requirements. Simplified from Schiemer & Waidbacher (1992) and Nunn et al. (2007). 22 Table 2.1 Results from linear regression analysis of Environment Agency water quality data. 39 Table 2.2 Results from linear regression analysis of macroinvertebrate indices (Environment Agency data) against date. 41 Table 2.3 Results from River Habitat Surveys Surveys (Environment Agency data). 46 Table 2.4 Summary of hydro-acoustic survey results. 54 Table 2.5 Water Framework Directive classifications for the lower River Witham (Environment Agency, unpublished data). 57 Table 3.1 Details of common bream tagged and tracked during the study. Individual tag number, tag type, capture method, date tagged, capture site, mass (kg), fork length (mm), age determined by scale analysis, gender, nominal tag delays, tag life, length of dataset collected (days), projected tag expiration date and whether the tag automatically switched itself off (y) or ran until batteries ran flat (n). 65-8 Table 3.2 Mann-Whitney U tests results for comparisons of TDM and LR during ten day period post- surgery between freshly tagged (T) and control (C; previously tagged) fish during all five tagging events. Significant at < 0.005 following Bonferroni correction. 83 Table 3.3 Mann-Whitney U tests results for comparisons of TDM and LR between fish captured and translocated ~35 km downstream, and control fish not captured or translocated. 85 Table 5.1 The number of individual fish and the number of days between ten day home-range calculation periods used to determine the effects of seven independent artificial water level manipulations. 113 Table 5.2 Two sample t-test results for adjacent month pairings around artificial water level manipulations. Levels are manipulated biannually in spring (1st April) and autumn (1st November). Asterisks denote significance at < 0.004 following Bonferroni Correction. 117 Table 6.1 Sample size and sampling periods for the analysis of social networks for each group. 126 6 List of figures Page Figure 1.1 The lower reaches of the unmodified River Rees, South Island New Zealand, with complex meander and diverse flow patterns creating lentic and lotic habitat types (authors own photo). 18 Figure 1.2 Common bream distribution map redrawn from Wheeler (1978). 24 Figure 1.3 ‘Coarse fish migration occurrence causes and implications’ reproduced from Lucas et al. (1998) modified from Northcote (1978). 30 Figure 2.1 Map of the East Midlands and Lincolnshire. The lower River Witham flows from Lincoln to Boston and discharges into The Wash. 35 Figure 2.2 Plan of the lower River Witham in 1762 from Wheeler (1990). 38 Figure 2.3 Map of land use within the River Witham Catchment Flood Management Plan (CFMP) area (Environment Agency, 2008). 40 Figure 2.4 Mean daily flow (m3 s-1) of the Barlings Eau at Langworth bridge, this tributary generates the largest flow input into the lower river. 42 Figure 2.5 Langworth bridge gauging station on the Barlings Eau, a tributary of the lower river, during normal conditions (left) and the summer flooding (right) in June 2007 (authors own photos).