Controls on Phytoplankton Community Change in a Redeveloped Freshwater Dock: A Case Study of Salford Quays A thesis submitted to the University of Manchester for the degree of Ph. D. in the Faculty of Life Sciences 2014 Robert Philip Mansfield Contents Contents .............................................................................................................................................. 2 Tables .................................................................................................................................................. 6 Figures ................................................................................................................................................. 7 Abbreviations .................................................................................................................................... 12 Abstract ............................................................................................................................................. 13 Lay Abstract....................................................................................................................................... 14 Declaration ........................................................................................................................................ 15 Copyright Statement ......................................................................................................................... 16 Acknowledgements ........................................................................................................................... 19 1.0 General Introduction ............................................................................................................. 20 1.1 Bottom-up control ............................................................................................................ 22 1.2 Top-down control ............................................................................................................. 26 1.3 ‘Sideways’ control ............................................................................................................. 30 1.4 Management and prediction in freshwater ecosystems .................................................. 31 1.4.1 Monitoring species invasions .................................................................................... 35 1.5 Salford Quays: a highly successful water restoration project........................................... 37 1.6 Aims................................................................................................................................... 44 1.7 Details of each paper ........................................................................................................ 45 1.7.1 Paper 1: Drivers of change in a redeveloped urban dockland: long term trends in a highly simplified lake system .................................................................................................... 45 1.7.2 Paper 2: Generalised Additive Models reveal non-linear patterns and novel associations in a long term lake dataset ................................................................................... 45 2 1.7.3 Paper 3: Multiplex panels of Microsatellite Loci for the Invasive Bivalve Dreissena polymorpha allow determination of habitat connectivity at multiple spatial scales ............... 46 1.7.4 Paper 4: The spread and effects of the invasive bivalve Dreissena polymorpha in a restored urban waterway ......................................................................................................... 47 1.7.5 Paper 5: Annual and inter-annual water quality variation in an enclosed dockland and its relationship to the filter-feeding bivalve Dreissena polymorpha: implications for future management .................................................................................................................. 48 2.0 Drivers of change in a redeveloped urban dockland: long term trends in a highly simplified lake system ....................................................................................................................................... 49 2.1 Abstract ............................................................................................................................. 49 2.2 Introduction ...................................................................................................................... 50 2.3 Methods ............................................................................................................................ 54 2.4 Results ............................................................................................................................... 58 2.5 Discussion .......................................................................................................................... 73 2.6 Acknowledgements ........................................................................................................... 79 3.0 Generalised Additive Models reveal non-linear patterns and novel associations in a long term lake dataset .............................................................................................................................. 80 3.1 Abstract ............................................................................................................................. 80 3.2 Introduction ...................................................................................................................... 80 3.3 Methods ............................................................................................................................ 85 3.3.1 Study site & dataset .................................................................................................. 85 3.3.2 Climatic Variables ...................................................................................................... 85 3.3.3 Analysis ..................................................................................................................... 86 3.4 Results ............................................................................................................................... 86 3 3.4.1 Changes in phytoplankton abundance ..................................................................... 86 3.4.2 Zooplankton .............................................................................................................. 88 3.4.3 Comparison to other models .................................................................................... 90 3.5 Discussion .......................................................................................................................... 90 3.6 Acknowledgements ........................................................................................................... 94 3.7 Supplementary data: residual patterns for each GAM model .......................................... 95 3.7.1 Equation 1 ................................................................................................................. 95 3.7.2 Equation 2 ................................................................................................................. 96 3.7.3 Equation 3 ................................................................................................................. 97 3.7.4 Equation 4 ................................................................................................................. 98 4.0 Multiplex panels of Microsatellite Loci for the Invasive Bivalve Dreissena polymorpha allow determination of habitat connectivity at multiple spatial scales ..................................................... 99 4.1 Abstract ............................................................................................................................. 99 4.2 Introduction .................................................................................................................... 100 4.3 Methods .......................................................................................................................... 103 4.4 Results ............................................................................................................................. 104 4.5 Discussion ........................................................................................................................ 109 4.6 Acknowledgements ......................................................................................................... 110 4.7 Supplementary Maps ...................................................................................................... 111 5.0 The spread and effects of the invasive bivalve Dreissena polymorpha in a restored urban waterway ........................................................................................................................................ 113 5.1 Abstract ........................................................................................................................... 113 5.2 Introduction .................................................................................................................... 114 4 5.3 Methods .......................................................................................................................... 118 5.4 Results ............................................................................................................................. 121 5.5 Discussion .......................................................................................................................