Aquaculture Engineering

As aquaculture continues to grow at a rapid pace, understanding the engineering behind aquatic production facilities is of increasing importance for all those working in the industry. Aquaculture engineering requires knowledge of the many general aspects of engineering such as material technology, building design and construction, mechanical engineering, and environmental engineering. In this comprehensive book now in its second edition, author Odd-Ivar Lekang introduces these principles and demonstrates how such technical knowledge can be applied to aquaculture systems. Review of the first edition:'Fish farmers and other personnel involved in the aquaculture industry, suppliers to the fish farming business and designers and manufacturers will find this book an invaluable resource. The book will be an important addition to the shelves of all libraries in universities and research institutions where aquaculture, agriculture and environmental sciences are studied and taught.'Aquaculture Europe'A useful book that, hopefully, will inspire successors that focus more on warm water aquaculture and on large-scale mariculture such as tuna farming.'Cision Aquaculture Engineering 5 Copyright 6 Contents 7 Preface 17 1 Introduction 19 1.1 Aquaculture engineering 19 1.2 Classification of aquaculture 19 1.3 The farm: technical components in a system 20 1.3.1 Land-based hatchery and juvenile production farm 20 1.3.2 On-growing sea cage farm 22 1.4 Future trends: increased importance of aquaculture engineering 23 1.5 This textbook 24 References 24 2 Water Transport 25 2.1 Introduction 25 2.2 Pipe and pipe parts 25 2.2.1 Pipes 25 2.2.2 Valves 29 2.2.3 Pipe parts: fittings 30 2.2.4 Pipe connections: jointing 30 2.2.5 Mooring of pipes 31 2.2.6 Ditches for pipes 32 2.3 Water flow and head loss in channels and pipe systems 33 2.3.1 Water flow 33 2.3.2 Head loss in pipelines 34 2.3.3 Head loss in single parts (fittings) 36 2.4 Pumps 37 2.4.1 Types of pump 37 2.4.2 Some definitions 37 2.4.3 Pumping of water requires energy 40 2.4.4 Centrifugal and propeller pumps 41 2.4.5 Pump performance curves and working point for centrifugal pumps 44 2.4.6 Change of water flow or pressure 46 2.4.7 Regulation of flow from selected pumps 47 References 49 3 Water Quality and Water Treatment: An Introduction 50 3.1 Increased focus on water quality 50 3.2 Inlet water 50 3.3 Outlet water 51 3.4 Water treatment 53 References 54 4 Fish Metabolism, Water Quality and Separation Technology 55 4.1 Introduction 55 4.2 Fish metabolism 55 4.2.1 Overview of fish metabolism 55 4.2.2 The energy budget 56 4.3 Separation technology 57 4.3.1 What are the impurities in water? 57 4.3.2 Phosphorus removal: an example 59 References 60 5 Adjustment of pH 61 5.1 Introduction 61 5.2 Definitions 61 5.3 Problems with low pH 62 5.4 pH of different water sources 62 5.5 pH adjustment 63 5.6 Examples of methods for pH adjustment 63 5.6.1 Lime 63 5.6.2 Sea water 65 5.6.3 Lye or hydroxides 65 References 66 6 Removal of Particles: Traditional Methods 68 6.1 Introduction 68 6.2 Characterization of the water 69 6.3 Methods for particle removal in fish farming 69 6.3.1 Mechanical filters and microscreens 70 6.3.2 Depth filtration: granular medium filters 73 6.3.3 Settling or gravity filters 76 6.3.4 Integrated treatment systems 78 6.4 Hydraulic loads on filter units 80 6.5 Purification efficiency 80 6.6 Dual drain tank 81 6.7 Local ecological solutions 82 References 82 7 Protein Skimming, Flotation, Coagulation and Flocculation 84 7.1 Introduction 84 7.1.1 Surface tension, cohesion and adhesion 86 7.1.2 Surfactants 88 7.2 Mechanisms for attachment and removal 89 7.2.1 Attachment of particles to rising bubbles by collision, typically in flotation 90 7.2.2 Improving colloid and particle removal rates: pretreatment 91 7.2.3 Attachment of surface-active substances, typically in protein skimmers 96 7.2.4 Particle attachment by nucleation 98 7.3 Bubbles 98 7.3.1 What is a gas bubble? 98 7.3.2 Methods for bubble generation 98 7.3.3 Bubble size 100 7.3.4 Bubble coalescence 101 7.4 Foam 101 7.4.1 What is foam? 101 7.4.2 Foam stability 102 7.4.3 Foam breakers 103 7.5 Introduction of bubbles affects the gas concentration in the water 103 7.6 Use of bubble columns in aquaculture 103 7.7 Performance of protein skimmers and flotation plants in aquaculture 104 7.7.1 What is removed in inlet or effluent aquaculture water with the use of protein skimmers? 104 7.7.2 Factors affecting the efficiency of protein skimming in aquaculture 105 7.7.3 Use of ozone 107 7.7.4 Bubble fractionation 107 7.8 Design and dimensioning of protein skimmers and flotation plants 108 7.8.1 Protein skimmers: principles and design 108 7.8.2 Protein skimmers: dimensioning 110 7.8.3 Flotation plant 110 7.8.4 Important factors affecting design of a DAF plant 111 References 113 8 Membrane Filtration 117 8.1 History and use 117 8.2 What is membrane filtration? 118 8.3 Classification of membrane filters 119 8.4 Flow pattern 121 8.5 Membrane shape/geometry 122 8.6 Membrane construction/morphology 123 8.7 Flow across membranes 124 8.8 Membrane materials 124 8.9 Fouling 125 8.10 Automation 126 8.11 Design and dimensioning of membrane filtration plants 126 8.12 Some examples of results with membranes used in aquaculture 130 References 130 9 Sludge Production, Treatment and Utilization 132 9.1 What is the sludge? 132 9.2 Dewatering of sludge 132 9.3 Stabilization of sludge 133 9.4 Composting of the sludge: aerobic decomposition 133 9.5 Fermentation and biogas production: anaerobic decomposition 135 9.6 Addition of lime 136 9.7 Utilization of sludge 136 References 136 10 Disinfection 138 10.1 Introduction 138 10.2 Basis of disinfection 139 10.2.1 Degree of removal 139 10.2.2 Chick’s law 139 10.2.3 Watson’s law 139 10.2.4 Dose–response curve 140 10.3 Ultraviolet light 140 10.3.1 Function 140 10.3.2 Mode of action 140 10.3.3 Design 141 10.3.4 Design specification 142 10.3.5 Dose 143 10.3.6 Special problems 143 10.4 Ozone 143 10.4.1 Function 143 10.4.2 Mode of action 143 10.4.3 Design specification 144 10.4.4 Ozone dose 145 10.4.5 Special problems 145 10.4.6 Measuring ozone content 146 10.5 Advanced oxidation technology 147 10.5.1 Redox potential 147 10.5.2 Methods utilizing AOT 148 10.6 Other disinfection methods 149 10.6.1 Photozone 149 10.6.2 Heat treatment 149 10.6.3 Chlorine 149 10.6.4 Changing the pH 150 10.6.5 Natural methods: ground filtration or constructed wetland 150 10.6.6 Membrane filtration 150 References 150 11 Heating and Cooling 152 11.1 Introduction 152 11.2 Heating requires energy 152 11.3 Methods for heating water 153 11.4 Heaters 154 11.4.1 Immersion heaters 154 11.4.2 Oil and gas burners 155 11.5 Heat exchangers 156 11.5.1 Why use heat exchangers? 156 11.5.2 How is the heat transferred? 156 11.5.3 Factors affecting heat transfer 157 11.5.4 Important parameters when calculating the size of heat exchangers 158 11.5.5 Types of heat exchanger 159 11.5.6 Flow pattern in heat exchangers 162 11.5.7 Materials in heat exchangers 162 11.5.8 Fouling 163 11.6 Heat pumps 164 11.6.1 Why use heat pumps? 164 11.6.2 Construction and function of a heat pump 164 11.6.3 Log pressure–enthalpy (p–H) 165 11.6.4 Coefficient of performance 166 11.6.5 Installations of heat pumps 166 11.6.6 Management and maintenance of heat pumps 167 11.7 Composite heating systems 167 11.8 Chilling of water 171 References 172 12 Aeration and Oxygenation 173 12.1 Introduction 173 12.2 Gases in water 173 12.3 Gas theory: aeration 175 12.3.1 Equilibrium 175 12.3.2 Gas transfer 176 12.4 Design and construction of aerators 177 12.4.1 Basic principles 177 12.4.2 Evaluation criteria 178 12.4.3 Example of designs for different types of aerator 179 12.5 Oxygenation of water 183 12.6 Theory of oxygenation 184 12.6.1 Increasing the equilibrium concentration 184 12.6.2 Gas transfer velocity 184 12.6.3 Addition under pressure 184 12.7 Design and construction of oxygen injection systems 184 12.7.1 Basic principles 184 12.7.2 Where to install the injection system 185 12.7.3 Evaluation of methods for injecting oxygen gas 186 12.7.4 Examples of oxygen injection system designs 187 12.8 Oxygen gas characteristics 190 12.9 Sources of oxygen 190 12.9.1 Oxygen gas 191 12.9.2 Liquid oxygen 191 12.9.3 On-site oxygen production 193 12.9.4 Selection of source 193 Appendix 12.1 195 Appendix 12.2 195 References 195 13 Ammonia Removal 197 13.1 Introduction 197 13.2 Biological removal of ammonium ion 197 13.3 Nitrification 198 13.4 Construction of nitrification filters 199 13.4.1 Flow-through system 200 13.4.2 The filter medium in the biofilter 201 13.4.3 Rotating biofilter (biodrum) 201 13.4.4 Moving bed bioreactor (MBBR) 202 13.4.5 Granular filters/bead filters 203 13.5 Management of biological filters 203 13.6 Example of biofilter design 204 13.7 Denitrification 204 13.8 Chemical removal of ammonia 205 13.8.1 Principle 205 13.8.2 Construction 205 References 206 14 Traditional Recirculation and Water Re-use Systems 208 14.1 Introduction 208 14.2 Advantages and disadvantages of re-use systems 208 14.2.1 Advantages of re-use systems 208 14.2.2 Disadvantages of re-use systems 209 14.3 Definitions 209 14.3.1 Degree of re-use 209 14.3.2 Water exchange in relation to amount of fish 210 14.3.3 Degree of purification 211 14.4 Theoretical models for construction of re-use systems 211 14.4.1 Mass flow in the system 211 14.4.2 Water requirements of the system 211 14.4.3 Connection between outlet concentration, degree of re-use and effectiveness of the water treatment system 213 14.5 Components in a re-use system 214 14.6 Design of a re-use system 215 References 218 15 Natural Systems, Integrated Aquaculture, Aquaponics, Biofloc 219 15.1 Characterization of production systems 219 15.2 Closing the nutrient loop 219 15.3 Re-use of water: an interesting topic 219 15.4 Natural systems, polyculture, integrated systems 221 15.4.1 Integrated multitropic aquaculture 221 15.4.2 Biological purification of water: some basics 221 15.4.3 Examples of systems utilizing photoautotrophic organisms: aquaponics 222 15.4.4 Examples of systems utilizing heterotrophic bacteria: active sludge and bioflocs 223 15.4.5 The biofloc system 224 References 226 16 Production Units: A Classification 228 16.1 Introduction 228 16.2 Classification of production units 228 16.2.1 Intensive/extensive 228 16.2.2 Fully controlled/semi-controlled 231 16.2.3 Land based/tidal based/sea based 231 16.2.4 Other 232 16.3 Possibilities for controlling environmental impact 233 17 Egg Storage and Hatching Equipment 234 17.1 Introduction 234 17.2 Systems where the eggs stay pelagic 235 17.2.1 The incubator 235 17.2.2 Water inlet and water flow 236 17.2.3 Water outlet 236 17.3 Systems where the eggs lie on the bottom 237 17.3.1 Systems where the eggs lie in the same unit from spawning to fry ready for start feeding 237 17.3.2 Systems where the eggs must be removed before hatching 239 17.3.3 Systems where storing, hatching and first feeding are carried out in the same unit 241 References 241 18 Tanks, Basins and Other Closed Production Units 242 18.1 Introduction 242 18.2 Types of closed production unit 242 18.3 How much water should be supplied? 244 18.4 Water exchange rate 245 18.5 Ideal or non-ideal mixing and water exchange 246 18.6 Tank design 246 18.7 Flow pattern and self-cleaning 249 18.8 Water inlet design 251 18.9 Water outlet or drain 253 18.10 Dual drain 255 18.11 Other installations 255 References 255 19 Ponds 257 19.1 Introduction 257 19.2 The ecosystem 257 19.3 Different production ponds 258 19.4 Pond types 259 19.4.1 Construction principles 259 19.4.2 Drainable or non-drainable 260 19.5 Size and construction 261 19.6 Site selection 261 19.7 Water supply 262 19.8 The inlet 263 19.9 The outlet: drainage 263 19.10 Pond layout 265 References 265 20 Sea Cages 267 20.1 Introduction 267 20.2 Site selection 268 20.3 Environmental factors affecting a floating construction 269 20.3.1 Waves 269 20.3.2 Wind 275 20.3.3 Current 275 20.3.4 Ice 277 20.4 Construction of sea cages 277 20.4.1 Cage collar or framework 278 20.4.2 Weighting and stretching 278 20.4.3 Net bags 280 20.4.4 Breakwaters 281 20.4.5 Examples of cage constructions 282 20.5 Mooring systems 284 20.5.1 Design of the mooring system 285 20.5.2 Description of the single components in a pre-stressed mooring system 287 20.5.3 Examples of mooring systems in use 292 20.6 Calculation of forces on a sea cage farm 292 20.6.1 Types of force 293 20.6.2 Calculation of current forces 294 20.6.3 Calculation of wave forces 297 20.6.4 Calculation of wind forces 298 20.7 Calculation of the size of the mooring system 298 20.7.1 Mooring analysis 298 20.7.2 Calculation of sizes for mooring lines 299 20.8 Control of mooring systems 301 References 301 21 Feeding Systems 304 21.1 Introduction 304 21.1.1 Why use automatic feeding systems? 304 21.1.2 What can be automated? 304 21.1.3 Selection of feeding system 304 21.1.4 Feeding system requirements 304 21.2 Types of feeding equipment 305 21.2.1 Feed blowers 305 21.2.2 Feed dispensers 305 21.2.3 Demand feeders 305 21.2.4 Automatic feeders 307 21.2.5 Feeding systems 311 21.3 Feed control 313 21.4 Feed control systems 314 21.5 Dynamic feeding systems 314 References 315 22 Internal Transport and Size Grading 317 22.1 Introduction 317 22.2 The importance of fish handling 317 22.2.1 Why move the fish? 317 22.2.2 Why size grade? 318 22.3 Negative effects of handling the fish 322 22.4 Methods and equipment for internal transport 323 22.4.1 Moving fish with a supply of external energy 323 22.4.2 Methods for moving fish without the need for external energy 333 22.5 Methods and equipment for size grading of fish 334 22.5.1 Equipment for grading that requires an energy supply 334 22.5.2 Methods for voluntary grading (self-grading) 344 References 344 23 Transport of Live Fish 346 23.1 Introduction 346 23.2 Preparation for transport 346 23.3 Land transport 347 23.3.1 Land vehicles 347 23.3.2 The tank 347 23.3.3 Supply of oxygen 348 23.3.4 Changing the water 349 23.3.5 Density 349 23.3.6 Instrumentation and stopping procedures 350 23.4 Sea transport 350 23.4.1 Well boats 350 23.4.2 The well 350 23.4.3 Density 351 23.4.4 Instrumentation 352 23.4.5 Recent trends in well boat technology 352 23.5 Air transport 353 23.6 Other transport methods 354 23.7 Cleaning and re-use of water 354 23.8 Use of additives 355 References 355 24 Instrumentation and Monitoring 357 24.1 Introduction 357 24.2 Construction of measuring instruments 358 24.3 Instruments for measuring water quality 358 24.3.1 Measuring temperature 359 24.3.2 Measuring oxygen content of the water 359 24.3.3 Measuring pH 360 24.3.4 Measuring conductivity and salinity 360 24.3.5 Measuring total gas pressure and nitrogen saturation 360 24.3.6 Other 361 24.4 Instruments for measuring physical conditions 362 24.4.1 Measuring the water flow 362 24.4.2 Measuring water pressure 365 24.4.3 Measuring water level 365 24.5 Equipment for counting fish, measuring fish size and estimation of total biomass 367 24.5.1 Counting fish 367 24.5.2 Measuring fish size and total fish biomass 368 24.6 Monitoring systems 370 24.6.1 Sensors and measuring equipment 371 24.6.2 Monitoring centre 371 24.6.3 Warning equipment 372 24.6.4 Regulation equipment 373 24.6.5 Maintenance and control 373 References 373 25 Buildings and Superstructures 375 25.1 Why use buildings? 375 25.2 Types, shape and roof design 375 25.2.1 Types 375 25.2.2 Shape 376 25.2.3 Roof design 376 25.3 Load-carrying systems 377 25.4 Materials 377 25.5 Prefabricate or build on site? 380 25.6 Insulated or not? 380 25.7 Foundations and ground conditions 380 25.8 Design of major parts 381 25.8.1 Floors 381 25.8.2 Walls 381 25.9 Ventilation and climate control 382 References 384 26 Design and Construction of Aquaculture Facilities: Some Examples 385 26.1 Introduction 385 26.2 Land-based hatchery, juvenile and on-growing production plant 385 26.2.1 General 385 26.2.2 Water intake and transfer 385 26.2.3 Water treatment department 395 26.2.4 Production rooms 396 26.2.5 Feed storage 401 26.2.6 Disinfection barrier 401 26.2.7 Other rooms 401 26.2.8 Outlet water treatment 401 26.2.9 Important equipment 402 26.3 On-growing production, sea cage farms 403 26.3.1 General 403 26.3.2 Site selection 405 26.3.3 The cages and the fixed equipment 405 26.3.4 The base station 408 26.3.5 Net handling 409 26.3.6 Boat 410 References 411 27 Planning Aquaculture Facilities 412 27.1 Introduction 412 27.2 The planning process 412 27.3 Site selection 413 27.4 Production plan 413 27.5 Room programme 415 27.6 Necessary analyses 415 27.7 Drawing up alternative solutions 416 27.8 Evaluation of and choosing between the alternative solutions 417 27.9 Finishing plans, detailed planning 417 27.10 Function test of the plant 417 27.11 Project review 420 References 420 Index 421 Aquaculture Engineering......Page 5 Copyright......Page 6 Contents......Page 7 Preface......Page 17 1.2 Classification of aquaculture......Page 19 1.3.1 Land-based hatchery and juvenile production farm......Page 20 1.3.2 On-growing sea cage farm......Page 22 1.4 Future trends: increased importance of aquaculture engineering......Page 23 References......Page 24 2.2.1 Pipes......Page 25 2.2.2 Valves......Page 29 2.2.4 Pipe connections: jointing......Page 30 2.2.5 Mooring of pipes......Page 31 2.2.6 Ditches for pipes......Page 32 2.3.1 Water flow......Page 33 2.3.2 Head loss in pipelines......Page 34 2.3.3 Head loss in single parts (fittings)......Page 36 2.4.2 Some definitions......Page 37 2.4.3 Pumping of water requires energy......Page 40 2.4.4 Centrifugal and propeller pumps......Page 41 2.4.5 Pump performance curves and working point for centrifugal pumps......Page 44 2.4.6 Change of water flow or pressure......Page 46 2.4.7 Regulation of flow from selected pumps......Page 47 References......Page 49 3.2 Inlet water......Page 50 3.3 Outlet water......Page 51 3.4 Water treatment......Page 53 References......Page 54 4.2.1 Overview of fish metabolism......Page 55 4.2.2 The energy budget......Page 56 4.3.1 What are the impurities in water?......Page 57 4.3.2 Phosphorus removal: an example......Page 59 References......Page 60 5.2 Definitions......Page 61 5.4 pH of different water sources......Page 62 5.6.1 Lime......Page 63 5.6.3 Lye or hydroxides......Page 65 References......Page 66 6.1 Introduction......Page 68 6.3 Methods for particle removal in fish farming......Page 69 6.3.1 Mechanical filters and microscreens......Page 70 6.3.2 Depth filtration: granular medium filters......Page 73 6.3.3 Settling or gravity filters......Page 76 6.3.4 Integrated treatment systems......Page 78 6.5 Purification efficiency......Page 80 6.6 Dual drain tank......Page 81 References......Page 82 7.1 Introduction......Page 84 7.1.1 Surface tension, cohesion and adhesion......Page 86 7.1.2 Surfactants......Page 88 7.2 Mechanisms for attachment and removal......Page 89 7.2.1 Attachment of particles to rising bubbles by collision, typically in flotation......Page 90 7.2.2 Improving colloid and particle removal rates: pretreatment......Page 91 7.2.3 Attachment of surface-active substances, typically in protein skimmers......Page 96 7.3.2 Methods for bubble generation......Page 98 7.3.3 Bubble size......Page 100 7.4.1 What is foam?......Page 101 7.4.2 Foam stability......Page 102 7.6 Use of bubble columns in aquaculture......Page 103 7.7.1 What is removed in inlet or effluent aquaculture water with the use of protein skimmers?......Page 104 7.7.2 Factors affecting the efficiency of protein skimming in aquaculture......Page 105 7.7.4 Bubble fractionation......Page 107 7.8.1 Protein skimmers: principles and design......Page 108 7.8.3 Flotation plant......Page 110 7.8.4 Important factors affecting design of a DAF plant......Page 111 References......Page 113 8.1 History and use......Page 117 8.2 What is membrane filtration?......Page 118 8.3 Classification of membrane filters......Page 119 8.4 Flow pattern......Page 121 8.5 Membrane shape/geometry......Page 122 8.6 Membrane construction/morphology......Page 123 8.8 Membrane materials......Page 124 8.9 Fouling......Page 125 8.11 Design and dimensioning of membrane filtration plants......Page 126 References......Page 130 9.2 Dewatering of sludge......Page 132 9.4 Composting of the sludge: aerobic decomposition......Page 133 9.5 Fermentation and biogas production: anaerobic decomposition......Page 135 References......Page 136 10.1 Introduction......Page 138 10.2.3 Watson’s law......Page 139 10.3.2 Mode of action......Page 140 10.3.3 Design......Page 141 10.3.4 Design specification......Page 142 10.4.2 Mode of action......Page 143 10.4.3 Design specification......Page 144 10.4.5 Special problems......Page 145 10.4.6 Measuring ozone content......Page 146 10.5.1 Redox potential......Page 147 10.5.2 Methods utilizing AOT......Page 148 10.6.3 Chlorine......Page 149 References......Page 150 11.2 Heating requires energy......Page 152 11.3 Methods for heating water......Page 153 11.4.1 Immersion heaters......Page 154 11.4.2 Oil and gas burners......Page 155 11.5.2 How is the heat transferred?......Page 156 11.5.3 Factors affecting heat transfer......Page 157 11.5.4 Important parameters when calculating the size of heat exchangers......Page 158 11.5.5 Types of heat exchanger......Page 159 11.5.7 Materials in heat exchangers......Page 162 11.5.8 Fouling......Page 163 11.6.2 Construction and function of a heat pump......Page 164 11.6.3 Log pressure–enthalpy (p–H)......Page 165 11.6.5 Installations of heat pumps......Page 166 11.7 Composite heating systems......Page 167 11.8 Chilling of water......Page 171 References......Page 172 12.2 Gases in water......Page 173 12.3.1 Equilibrium......Page 175 12.3.2 Gas transfer......Page 176 12.4.1 Basic principles......Page 177 12.4.2 Evaluation criteria......Page 178 12.4.3 Example of designs for different types of aerator......Page 179 12.5 Oxygenation of water......Page 183 12.7.1 Basic principles......Page 184 12.7.2 Where to install the injection system......Page 185 12.7.3 Evaluation of methods for injecting oxygen gas......Page 186 12.7.4 Examples of oxygen injection system designs......Page 187 12.9 Sources of oxygen......Page 190 12.9.2 Liquid oxygen......Page 191 12.9.4 Selection of source......Page 193 References......Page 195 13.2 Biological removal of ammonium ion......Page 197 13.3 Nitrification......Page 198 13.4 Construction of nitrification filters......Page 199 13.4.1 Flow-through system......Page 200 13.4.3 Rotating biofilter (biodrum)......Page 201 13.4.4 Moving bed bioreactor (MBBR)......Page 202 13.5 Management of biological filters......Page 203 13.7 Denitrification......Page 204 13.8.2 Construction......Page 205 References......Page 206 14.2.1 Advantages of re-use systems......Page 208 14.3.1 Degree of re-use......Page 209 14.3.2 Water exchange in relation to amount of fish......Page 210 14.4.2 Water requirements of the system......Page 211 14.4.3 Connection between outlet concentration, degree of re-use and effectiveness of the water treatment system......Page 213 14.5 Components in a re-use system......Page 214 14.6 Design of a re-use system......Page 215 References......Page 218 15.3 Re-use of water: an interesting topic......Page 219 15.4.2 Biological purification of water: some basics......Page 221 15.4.3 Examples of systems utilizing photoautotrophic organisms: aquaponics......Page 222 15.4.4 Examples of systems utilizing heterotrophic bacteria: active sludge and bioflocs......Page 223 15.4.5 The biofloc system......Page 224 References......Page 226 16.2.1 Intensive/extensive......Page 228 16.2.3 Land based/tidal based/sea based......Page 231 16.2.4 Other......Page 232 16.3 Possibilities for controlling environmental impact......Page 233 17.1 Introduction......Page 234 17.2.1 The incubator......Page 235 17.2.3 Water outlet......Page 236 17.3.1 Systems where the eggs lie in the same unit from spawning to fry ready for start feeding......Page 237 17.3.2 Systems where the eggs must be removed before hatching......Page 239 References......Page 241 18.2 Types of closed production unit......Page 242 18.3 How much water should be supplied?......Page 244 18.4 Water exchange rate......Page 245 18.6 Tank design......Page 246 18.7 Flow pattern and self-cleaning......Page 249 18.8 Water inlet design......Page 251 18.9 Water outlet or drain......Page 253 References......Page 255 19.2 The ecosystem......Page 257 19.3 Different production ponds......Page 258 19.4.1 Construction principles......Page 259 19.4.2 Drainable or non-drainable......Page 260 19.6 Site selection......Page 261 19.7 Water supply......Page 262 19.9 The outlet: drainage......Page 263 References......Page 265 20.1 Introduction......Page 267 20.2 Site selection......Page 268 20.3.1 Waves......Page 269 20.3.3 Current......Page 275 20.4 Construction of sea cages......Page 277 20.4.2 Weighting and stretching......Page 278 20.4.3 Net bags......Page 280 20.4.4 Breakwaters......Page 281 20.4.5 Examples of cage constructions......Page 282 20.5 Mooring systems......Page 284 20.5.1 Design of the mooring system......Page 285 20.5.2 Description of the single components in a pre-stressed mooring system......Page 287 20.6 Calculation of forces on a sea cage farm......Page 292 20.6.1 Types of force......Page 293 20.6.2 Calculation of current forces......Page 294 20.6.3 Calculation of wave forces......Page 297 20.7.1 Mooring analysis......Page 298 20.7.2 Calculation of sizes for mooring lines......Page 299 References......Page 301 21.1.4 Feeding system requirements......Page 304 21.2.3 Demand feeders......Page 305 21.2.4 Automatic feeders......Page 307 21.2.5 Feeding systems......Page 311 21.3 Feed control......Page 313 21.5 Dynamic feeding systems......Page 314 References......Page 315 22.2.1 Why move the fish?......Page 317 22.2.2 Why size grade?......Page 318 22.3 Negative effects of handling the fish......Page 322 22.4.1 Moving fish with a supply of external energy......Page 323 22.4.2 Methods for moving fish without the need for external energy......Page 333 22.5.1 Equipment for grading that requires an energy supply......Page 334 References......Page 344 23.2 Preparation for transport......Page 346 23.3.2 The tank......Page 347 23.3.3 Supply of oxygen......Page 348 23.3.5 Density......Page 349 23.4.2 The well......Page 350 23.4.3 Density......Page 351 23.4.5 Recent trends in well boat technology......Page 352 23.5 Air transport......Page 353 23.7 Cleaning and re-use of water......Page 354 References......Page 355 24.1 Introduction......Page 357 24.3 Instruments for measuring water quality......Page 358 24.3.2 Measuring oxygen content of the water......Page 359 24.3.5 Measuring total gas pressure and nitrogen saturation......Page 360 24.3.6 Other......Page 361 24.4.1 Measuring the water flow......Page 362 24.4.3 Measuring water level......Page 365 24.5.1 Counting fish......Page 367 24.5.2 Measuring fish size and total fish biomass......Page 368 24.6 Monitoring systems......Page 370 24.6.2 Monitoring centre......Page 371 24.6.3 Warning equipment......Page 372 References......Page 373 25.2.1 Types......Page 375 25.2.3 Roof design......Page 376 25.4 Materials......Page 377 25.7 Foundations and ground conditions......Page 380 25.8.2 Walls......Page 381 25.9 Ventilation and climate control......Page 382 References......Page 384 26.2.2 Water intake and transfer......Page 385 26.2.3 Water treatment department......Page 395 26.2.4 Production rooms......Page 396 26.2.8 Outlet water treatment......Page 401 26.2.9 Important equipment......Page 402 26.3.1 General......Page 403 26.3.3 The cages and the fixed equipment......Page 405 26.3.4 The base station......Page 408 26.3.5 Net handling......Page 409 26.3.6 Boat......Page 410 References......Page 411 27.2 The planning process......Page 412 27.4 Production plan......Page 413 27.6 Necessary analyses......Page 415 27.7 Drawing up alternative solutions......Page 416 27.10 Function test of the plant......Page 417 References......Page 420 Index......Page 421 As aquaculture continues to grow at a rapid pace, understanding the engineering behind aquatic production facilities is of increasing importance for all those working in the industry. Aquaculture engineering requires knowledge of the many general aspects of engineering such as material technology, building design and construction, mechanical engineering, and environmental engineering. In this comprehensive book now in its second edition, author Odd-Ivar Lekang introduces these principles and demonstrates how such technical knowledge can be applied to aquaculture systems--[Résumé de l'éditeur] "As aquaculture continues to grow at a rapid pace, understanding the engineering behind aquatic production facilities is of increasing importance for all those working in the industry. Aquaculture engineering requires knowledge of the many general aspects of engineering such as material technology, building design and construction, mechanical engineering, and environmental engineering. In comprehensive book now in its second edition, author Odd-Ivar Lekang introduces these principles and demonstrates how such technical knowledge can be applied to aquaculture systems"-- Provided by publisher