1 Prologue ................................................... 1
2 Lake Types and Sediment Types .............................. 5
2.1 Lake Classifications ....................................... 5
2.1.1 Genetic Lake Types .................................. 5
2.1.2 Trophic Level Classifications ...................... 12
2.1.3 Thermal Lake Types ................................. 14
2.2 Sediment Classifications .................................. 17
2.2.1 Genetic Sediment Types ............................. 19
2.2.2 Descriptive Sediment Classifications ............... 22
2.3 Lake Type versus Sediment Type ............................ 24
3 Methods of Sampling ....................................... 32
3.1 General Requirements on Sampling Equipment ................ 32
3.2 Types of Sampling System .................................. 37
3.2.1 Number of Samples .................................. 39
3.2.2 The Sample Formula ................................. 40
3.2.3 Sampling in Different Environments - Statistical
Aspects ............................................ 43
3.2.4 Sub-Sampling ....................................... 48
3.3 Sediment Traps ............................................ 53
3.3.1 Physics of Sedimentation in Vessels ................ 53
3.3.2 Geometry of Vessels ................................ 56
3.3.3 Practical Aspects .................................. 60
3.3.4 Problems with Sediment Traps ....................... 61
3.4 The Cone Apparatus for in Situ Determination of Sediment
Types ..................................................... 62
3.5 Methods of Defining Concentrations ........................ 65
3.6 Sampling of Sediment Pore Water ........................... 69
4 Physical and Chemical Sediment Parameters ................. 73
4.1 Physical Parameters ....................................... 73
4.1.1 Water Content ...................................... 73
4.1.2 Loss on Ignition (Organic Content) ................. 76
4.1.3 Bulk Density ....................................... 80
4.1.4 Grain Size ......................................... 82
4.1.4.1 Methods of Analysis ....................... 82
4.1.4.2 Grain Size Classifications ................ 84
4.1.4.3 Statistical Definitions ................... 87
4.1.4.4 Grain Size Interrelationships ............. 91
4.2 Chemical Parameters ....................................... 95
4.2.1 Elemental Composition .............................. 95
4.2.2 Organic Carbon Compounds ........................... 98
4.2.2.1 Humic Compounds ........................... 98
4.2.2.2 Other Organic Substances ................. 100
4.2.3 Minerals in Lake Sediments ........................ 101
4.2.3.1 Carbonates ............................... 101
4.2.3.2 Silicates ................................ 104
4.2.3.3 Iron ..................................... 107
4.2.3.4 Phosphorus ............................... 108
4.2.3.5 Sulfides ................................. 112
4.2.3.6 Heavy Metals ............................. 113
5 Biological Parameters .................................... 118
5.1 Sediment-Living Algae .................................... 118
5.2 Macrophytes .............................................. 121
5.3 Benthic Invertebrates .................................... 122
5.3.1 Important Forms of Benthic Animals ................ 123
5.3.2 Feeding Mechanisms and Food Types Among Insects ... 127
5.3.3 Distribution of Benthic Fauna Within Lakes ........ 127
5.3.4 Benthic Lake Typologies ........................... 131
5.4 Bacteria ................................................. 133
5.4.1 Functional Classification of Bacteria ............. 134
5.4.2 Bacterial Turnover of Important Elements .......... 135
5.4.2.1 Oxidation and Reduction of Nitrogen
Compounds ................................ 135
5.4.2.2 Oxidation and Reduction of Sulfur
Compounds ................................ 136
5.4.2.3 Oxidation and Reduction of Iron .......... 138
5.4.2.4 Fermentation ............................. 138
5.4.2.5 Methane Formation ........................ 139
5.4.3 Decomposition of Organic Material - General
Concepts .......................................... 139
5.4.4 Strategies and Methods for Determination of
Bacterial Activity ................................ 143
5.4.4.1 The Whole-Lake Approach .................. 143
5.4.4.2 Bacterial Activity in Experimental
Procedures ............................... 143
5.4.4.3 Parameters Reflecting Total Bacterial
Activity ................................. 145
5.4.4.4 Factors Reflecting Defined Parts of
Bacterial Activity ....................... 147
6 Sedimentation in Lakes and Water Dynamics ................ 148
6.1 Physics of Sedimentation in Lakes ........................ 148
6.2 Geography of Sedimentation in Lakes ...................... 156
6.2.1 River-Mouth Areas ................................. 157
6.2.1.1 Delta Sedimentation ...................... 157
6.2.1.2 River Plume Sedimentation ................ 159
6.2.1.3 The Borderline Between River Action and
Wind/Wave Action ......................... 164
6.2.2 Open Water Areas .................................. 170
6.2.3 Temporal Variations ............................... 174
7 Lake Bottom Dynamics ..................................... 177
7.1 Definitions .............................................. 177
7.2 Processes of Resuspension ................................ 181
7.2.1 Entrainment ....................................... 181
7.2.2 Turbidific Sedimentation .......................... 184
7.2.3 Wind/Wave Influences .............................. 188
7.2.4 Topographical Influences .......................... 194
7.3 Methods to Determine Prevailing Bottom Dynamics .......... 200
7.3.1 Lake-Specific Methods ............................. 201
7.3.1.1 The Energy-Topography Formula ............ 201
7.3.1.2 The Characteristic Water Content Model ... 202
7.3.2 Site-Specific Methods ............................. 204
7.3.2.1 The ETA-Diagram .......................... 205
7.3.2.2 The Cone Apparatus ....................... 206
8 Sediment Dynamics and Sediment Age ....................... 213
8.1 Laminated Sediments ...................................... 213
8.2 Bioturbation ............................................. 218
8.2.1 Introduction ...................................... 218
8.2.2 Patchiness ........................................ 219
8.2.2.1 Areal Patchiness ......................... 219
8.2.2.2 Vertical Patchiness ...................... 222
8.2.2.3 Temporal Patchiness ...................... 222
8.2.2.4 Species-Specific Patchiness .............. 222
8.2.3 Modelling of Bioturbation/Biotransport ............ 224
8.2.3.1 A Dynamic Model .......................... 225
8.2.3.2 An Empirical Model ....................... 232
8.3 Sediment Age and Age Determination ....................... 237
8.3.1 Methods of Age Determination ...................... 237
8.3.1.1 Lead-210 ................................. 241
8.3.1.2 Cesium-137 ............................... 243
9 Release of Substances from Lake Sediments - the
Example of Phosphorus .................................... 244
9.1 Background and Presuppositions ........................... 244
9.2 Factors of Importance for Mobilization of Phosphorus ..... 246
9.2.1 Fractional Distribution of Particulate
Phosphorus ........................................ 246
9.2.2 Redox Conditions .................................. 247
9.2.3 pH ................................................ 248
9.2.4 Microbial Mineralization .......................... 249
9.2.5 Equilibrium Reactions ............................. 250
9.3 Transport Mechanisms ..................................... 250
9.3.1 Phosphorus in Sediment Pore Water ................. 250
9.3.2 Diffusion ......................................... 253
9.3.3 Turbulent Mixing/Bottom Dynamics .................. 253
9.3.4 Bioturbation ...................................... 254
9.3.5 Gas Convection .................................... 254
9.4 A General View of Phosphorus Release ..................... 255
10 Sediments in Aquatic Pollution Control Programmes ........ 258
10.1 Introduction ............................................. 258
10.2 Why Use Sediments? ....................................... 258
10.3 How to Use Sediments ..................................... 262
10.3.1 Principles of Metal Distribution in Aquatic
Systems ........................................... 263
10.3.1.1 The Type of Metal and Type of Pollution .. 264
10.3.1.2 The "Carrier Particles" .................. 265
10.3.1.3 The Environmental Characteristics ........ 269
10.3.1.4 Natural Background Levels ................ 271
10.3.2 The Contamination Factor .......................... 273
10.3.3 Case Study - River Kolbäcksan ..................... 274
10.3.4 The Degree of Contamination ....................... 280
11 Epilogue ................................................... 283
Appendix 1 Table for Student's t-Distribution ................. 285
Appendix 2 Computer Programmes in BASIC for Determination of
Biotransport.Time Stratification and Sediment
Compaction ............................................... 286
References .................................................... 295
Subject Index ................................................. 309
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