Durham E-Theses Phosphorus dynamics and submerged aquatic macrophytes in hell kettles Giantzoudis, Dimitris How to cite: Giantzoudis, Dimitris (2003) Phosphorus dynamics and submerged aquatic macrophytes in hell kettles, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/4079/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk PHOSPHORUS DYNAMICS AND SUBMERGED AQUATIC MACROPHYTES IN HELL KETTLES The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. BY DlMITRIS GlANTZOUDIS B.Sc. UNIVERSITY OF ESSEX M.Sc. NAPIER UNIVERSITY A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF DURHAM, ENGLAND SCHOOL OF BIOLOGICAL AND BIOMEDICAL SCIENCES FEBRUARY 2003 1 8 JUfo 2Q03 ABSTRACT A study was made of the phosphorus ecology of Hell Kettle ponds, a Site of Special Scientific Interest in County Durham, UK, in order to help establish the causes of the temporary "whitening" of Chara hispida in summer 1996. Chara hispida, the most abundant organism in Croft Kettle, one of the two small calcareous ponds comprising Hell Kettles, was first reported in 1777 and since then its presence has been accounted many times, perhaps being the longest continuous record for a freshwater algal species anywhere in the world. The aims were to assess the concentration and variability of aqueous N and P as well as a number of other physical and chemical variables on spatial and temporal scales and the response of Chara hispida to these changes. Studies focused on Croft Kettle and key aspects included analysis of water chemistry, P sequential fractionation of sediments, tissue N and P contents and surface phosphatase activities of Chara hispida. This involved monthly surveys of surface as well as depth profiles of water chemistry during 1999-2001 and many other visits. Data was also collected from Double Kettle and the farm-borehole (representing groundwater) for comparative means. Croft Kettle was stratified in summer (approximately May to October) with severe deoxygenation in the hypolimnion. Aqueous N and P concentrations were about 150 p,g L"1 TN and 15 \ig L"1 TP respectively, but showed high within-year and intra-annual variability. Episodic events and autumnal turnover caused only short-term increase in aqueous P concentrations and co-precipitation with CaCC>3 was suspected. Depth profile studies of sediments (0-35 cm) for TN and TP content and N:P ratio suggest historical changes in N and P dynamics. Seasonal changes as well as a high range of tissue N and P contents were observed in C. hispida apical tips during this survey, possibly indicating that C. hispida is capable of rapid nutrient uptake and storage. Supportive evidence for this hypothesis arose from incubations of C. hispida under a series of aqueous P concentrations as well as the seasonal study on phosphatase activity. C. hispida apical tips collected from Double Kettle had on average higher tissue N and P contents than those collected from Croft Kettle, probably corresponding to the higher nutrient content of Double Kettle's water. Possible reasons for aquatic vegetation changes as well as the "whitening" of C. hispida during summer 1996 are discussed. Unusually warm summer along with wind- protected shores due to the dense reed vegetation may have resulted to reduced water mixing, light penetration and increased deoxygenation in the hypolimnion and thus stress on C. hispida. However, there is no indication of a long-term destabilization of the system indicating that the event of 1996 was only a "temporary instability". 2 LIST OF ABBREVIATIONS AND ACRONYMS ANOVA analysis of variance APA alkaline phosphatase activity ASFA automatic segmented flow analyser BD bicarbonate buffered dithionite solution bis-pNPP bis-p-nitrophenyl phosphate BSAC British Sub-Aqua Club DW deionised water DIN dissolved inorganic nitrogen DMG 3, 3-dimethyl-glutaric acid DNA deoxyribonycleic acid d.wt dry weight EA Environment Agency of England and Wales EDTA ethylenediaminetetra-acetic acid EN English Nature FRP filtrable reactive phosphorus FOP filtrable organic phosphorus FTP filtrable total phosphorus g gravitational force GIS geographical information systems HEPES (N-[2-Hydroxyethyl]piperazine-N-[2-ethanesulphonic acid]) Km Michaelis constant Ks apparent half-saturation constant for enzymatic activity MU 4-methylumbelliferone MUP 4-methylumbelliferyl phosphate NCC Nature Conservancy Council NERC Natural Environment Research Council NIES National Institute for Environmental Studies of Japan NRA National Rivers Authority NVC National Vegetation Classification NWA Northumbrian Water Authority PAR photosynthetically active radiation (400-700 nm) Pi phosphate (any form of orthophosphate) PDE phosphodiester PDEase phosphodiesterase PME phosphomonoester PMEase phosphomonoesterase pNP p-nitrophenol pNP? p-nitrophenyl phosphate PP particulate phosphorus SD standard deviation SE standard error SSSI Site of Special Scientific Interest TIN total inorganic nitrogen TP total phosphorus WTW Wissenschaftliche-Technische Werkstatten w/v weight/volume ACKNOWLEDGEMENTS I would like to thank Northumbrian Water pic for financing the studentship and further financial help from English Nature and the Environment Agency for dating sediment cores and some of the fieldwork. Special thanks to Prof. Brian Whitton and Dr Robert Baxter for their supervision, advice and guidance. I also appreciate the interest in the project from staff in the various organizations, especially Dr C.J. Spray (Northumbrian Water), S. Hedley and J. Barrett (English Nature). Access to the records held by English Nature was most helpful. Mr R.A. Fell, the owner of the ponds, not only gave permission for frequent access to the site, but showed keen interest in the project. Several colleagues in the School of Biological and Biomedical Sciences have helped. Dr D. Hyde provided overall advice on diving and helped with most dives; thanks also to Dr S.D. Twiss and A.J.W. Yates (Physics) for assistance with diving during the project and Charlotte Johnston on a pre-project dive. Prof. B. Huntley, Dr J.R.M. Allen and associates collected a sediment core on 12 March 1999. Dr B.L. Turner stimulate and advised on P analysis of sediments. A number of other people have helped at the field site, especially Dr R.S. Hopkin and N.T.W. Ellwood (Biological Sciences), A. Dimitriadis (Physics), N. Galiatsatos (Geography) and L. Tzonis (Economics); D.I. Griss (environmental consultant and local angler) provided interesting information about the fish. Dr M.G. Kelly (Bowburn Consultancy) and G. Cummins made a report on diatoms and pollen in the sediments respectively and a summary of this work is included here. Dr J. Lamont-Black (Civil Engineering, University of Newcastle-upon-Tyne) showed me some of his analytical data for the ponds and groundwater (the well) and Dr I.M. Head (Fossil Fuels and Environmental Geochemistry, University of Newcastle) sent interesting papers about a population of the bacterium Achromatium from Croft Kettle. Most of all I would like to thank my parents for their unconditional support. 5 CONTENTS Abstract List of Abbreviations and Acronyms Acknowledgements Contents List of Tables List of Figures CHAPTER 1 Introduction 1.1 Preamble 1.2 Hell Kettles 1.3 Ponds 1.4 Nutrients in freshwaters 1.41 Introduction 1.42 Nitrogen 1.43 Phosphorus 1.44 Eutrophication 1.5 Sources of phosphorus 1.51 Introduction 1.52 Weathering products 1.53 Atmospheric deposition 1.54 Point and diffuse sources 1.55 Biological production 1.6 Phosphorus cycling in lentic systems 1.61 Introduction 1.62 Phosphorus acquisition 1.63 Sedimentation 1.64 Sediments 1.65 Resuspension 1.7 Charophytes 1.71 Ecology and distribution 1.72 Relationship with phosphorus 1.8 Aims CHAPTER 2 Methods 2.1 Safety 2.2 Standard laboratory techniques 46 2.3 Sampling programme 46 2.4 Physical and chemical variables measured on site 48 2.5 Water analysis 50 2.51 Introduction 50 2.52 Nitrogen 50 2.53 Phosphorus 53 2.54 Dissolved oxygen 54 2.55 Total alkalinity 55 2.56 Silica 55 2.57 Suspended chlorophyll a in water 55 2.6 Chara hispida studies 56 2.61 Introduction 56 2.62 Marl removal 57 2.63 Phosphatase activity 57 2.631 Assay medium 57 2.632 Substrates 57 2.633 Buffers 58 2.634 Phosphatase assay 58 2.64 Analysis of whole Chara hispida plants 59 2.65 Laboratory experiments 59 2.651 Introduction 59 2.652 Effect of temperature on Chara hispida shoots 60 2.653 Effect of phosphorus enrichment on Chara hispida shoots 60 2.7 Sediments and cores 61 2.71 Phosphorus sequential fractionation 61 2.72 Deep cores 62 2.8 Nutrient analysis of plants and sediments 63 2.81 Introduction 63 2.82 Digestion 63 2.83 Automated analysis of nitrogen and phosphorus 64 2.9 Computing and