Environmental impacts from feeds used in aquaculture systems in the vicinity of mekong river vietnam

ENVIRONMENTAL IMPACTS FROM FEEDS USED IN AQUACULTURE SYSTEMS IN THE VICINITY OF THE MEKONG RIVER, VIETNAM by Chau Thi Da A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Aquaculture and Aquatic Resources Management Examination Committee: Nationality: Previous Degree: Scholarship Donor: Dr Amararatne Yakupitiyage (Chairperson) Dr Wenresti G Gallardo (Member) Dr Hakan Berg (Member) Dr Yang Yi (Member) Vietnam Bachelor of Science in Agronomy Cantho University, Vietnam MOET, Vietnam - AIT Fellowship Asian Institute of Technology School of Environment Resources and Development Thailand May, 2007 i ACKNOWLEDGEMENTS I wish to extend my deepest gratitude to my advisor Dr Amararatne Yakupitiyage, for his valuable guidance and constant encouragement, great patience, suggestion and advise through out the study period Despite his exceptionally busy schedule, he spares his time and efforts in going through the research draft, making alterations and giving appropriate verbal correction The present shape of thesis would not have been possible without his extensive guidance and correction I wish to express special appreciation and my sincere thans to Dr Wenresti G Gallardo, Dr Hakan Berg and Dr Yang Yi as members of examination committee for their valuable guidance, constant encouragement, great patience, and valuable suggestions Thanks are due to my wife, Ms Thai Huynh Phuong Lan, who showed me numerous ways to improve my English expressions in this thesis I am grateful to Ministry of Education and Training, Vietnam and An Giang University Vietnam for its awards of the Masters scholarship I also sincere thanks to Dr Nguyen Thanh Phuong, Dr Truong Quoc Phu (Department of Aquaculture and Fisheries – Can Tho University, Vietnam) and Mr Nguyen Thanh Son, Mr Bui Xuan Thanh, Mr Nguyen Minh Du and my fellow students Mr Nguyen Long Doat Quoc, Mr Nguyen Minh Ngoc and Mr Nguyen Ngoc Lan in Department of Agriculture & Natural Resource, An Giang University Vietnam) for their valuable help during this thesis Last but not least, this work is dedicated to my parents and family members for their love, patience, encouragement and moral support to complete my study in AIT I would like to thank to all of my classmates for their support during this study ii ABSTRACT This study was conducted in My Hoa Hung village in Long Xuyen city, An Giang province, Mekong River in Vietnam during August to December 2007, to assess environmental impacts from feeds used in aquaculture systems such as intensive fish cages, pens and ponds culture on and in the vicinity of Mekong River, Vietnam (e.g Pangasius Hypopthalamus, Colossoma macropomum species) Moreover, the purpose of this study is to investigate the effects of feeds in the intensive aquaculture systems towards water environment The study was commenced by a field survey of twenty Pangasius hypophthalmus cage farmers, 18 Pangasius hypophthalmus pond farmers, 20 Pangasius hypophthalmus pen farmers and 15 Colossoma macropomum cage farmers The survey showed that the fish culture in An Giang province was developed and operated by farmer’s indigenous knowledge The fish density is quite high of 80-105 fish/m2 as compared with the optimum range of 30-60 fish/m2 There are three kinds of popular feeds such as homemade, pellet and Pangasius waste used in this area The pellet feed is more effective in terms of economic profit, less environmental pollution, better product quality and reduction in trash fishes from nature Among three of culture systems, pen culture has more economic benefits because this system is separate from other systems It is located in the alluvial grounds with high water turnover so that fish is not affected by disease transmission from other farms Water quality of the river is still in the limit for fish culture in three surveyed months of August, October and December Nitrogen and phosphorus concentrations of October are lowest because this time is the peak up of flooding season In this study the adverse effects of fish culture is not revealed clearly due to the survey carried out in the rainy season iii Table of Contents CHAPTER TITLE Title Page Acknowledgements Abstract Table of Contents List of Tables List of Figures PAGE i ii iii iv vi viii Introduction 1.1 Introduction 1.2 General objective 1.3 Specific objectives 1 2 Literature Review 2.1 Basic biology of Pangasius hypopthalamus 2.2 Wild populations 2.3 Source of seed stock 2.4 Brood stock and rearing conditions 2.5 Fish culture systems in An Giang province, Mekong River in Vietnam 2.6 Production statistics 2.7 Feeds and Feeding 2.8 Nutrient requirements of Pangasius hypopthalamus 2.9 Environmental impacts 2.10 Basic biology of Colossoma macropomum 3 7 11 12 14 15 17 Material and Methods 3.1 Steps of the study 3.2 Socio-technical survey 3.3 Laboratory studies 3.4 Assessment and comparison of the different systems 3.5 Data analysis 3.6 Assessment of effluent and feed waste contribution 19 19 19 23 29 29 29 Results and Discussion: Survey of aquaculture systems in An Giang 34 province 4.1 4.2 4.3 4.4 4.5 General information Socio-economic survey Technological survey of aquaculture systems Costs and return benefit analysis (1 US$ = 15,000 VND) Strength (opportunity), constraints and environmental awareness Results and Discussion: Assessments of contribution of feed waste used in aquaculture systems and water quality parameters 5.1 Introduction iv 34 36 40 53 57 60 60 5.2 5.3 5.4 5.5 Materials and methods Results Feed utilization efficiency Amount of nitrogen (N) and phosphorous (P) in the waste loading from feeds used into the river 5.6 Discussions Conclusions Recommendations for future study Reference Appendixes Questionnaire Appendix A: Socio-technical aspects of aquaculture systems information Appendix B: Economic aspects of aquaculture systems information Appendix C: Water quality parameters of aquaculture systems in An Giang province, Mekong River in Vietnam Appendix D: Water quality parameters in aquaculture systems in three seasons v 60 61 70 71 73 76 77 78 84 84 95 100 102 105 List of Tables TABLE No TITLE PAGE 2.1 Estimated numbers of Pangasius hypophthalmus fry caught in the dais fishery in Viet Nam 2.2 Status of Pangasius hypophthalmus pond culture in An Giang province 10 2.3 Aquaculture using trash fish (Edwards, 2004) 13 3.1 Parameters and analysis of feed 25 3.2 Samplings were carried out on three seasons in area selected 26 3.3 Parameters and analysis of water quality 27 4.1 Average age of fish farm manager in An Giang province 37 4.2 The distribution (%) of educational level of fish farming managers in An Giang province 38 4.3 Farming experience of fish managers in An Giang province (%) 38 4.4 Training times for fish manager (%) 39 4.5 Total water volumes and total area of aquaculture systems in An Giang province 44 4.6 Production season of Pangasius hypophthalmus in An Giang province 44 4.7 Stocking densities in aquaculture systems in An Giang Province 45 4.8 Ingredients of homemade feed for Pangasius hypophthalmus species and percentage of farmers in An Giang 47 4.9 The ratio % materials in homemade feed used by household’s fish cage 4.10 Ingredients of homemade feed used for Colossoma macropomum species and percentage of farmers in An Giang province 48 4.11 Variable costs of production unit of aquaculture systems in An Giang province 54 4.12 Net return of fish farmers in An Giang province 55 4.13 The percentages (%) of name of buyer in Mekong Delta, in Vietnam 57 5.1 Water level water level Hmax (m) in Tan Chau district of An Giang province and Can Tho province in years having great floods 61 5.2 Water temperature (T0C) in aquaculture systems in three seasons 62 5.3 pH levels in three seasons of aquaculture systems in An Giang province 63 5.4 DO in aquaculture systems in three seasons 64 vi 48 5.5 TSS in aquaculture systems in three seasons 65 5.6 Nitrite-N (NO2) and nitrate-N (NO3) in aquaculture systems in three seasons 66 5.7 Total nitrogen in aquaculture systems in three seasons 68 5.8 Total nitrogen in aquaculture systems in three seasons 69 5.9 Fish yield (tons/crop/culture unit) and FCR in relation to feed and feeding level used in aquaculture systems 71 5.10 Feed consumed and fish biomass in dry matter related to waste material uneaten feed and metabolize (tone/crop/culture unit) 72 5.11 Fish carcasses (adult fish) and feeds compositions analysis 5.12 Amount nitrogen (N) and phosphorous (P) (tons) content in feed used, fish biomass and waste material in uneaten feed in different culture systems 73 vii 72 List of Figures FIGURES No TITLE PAGE 2.1 Aquaculture timeline for both cage and pond production in Vietnam 2.2 Annual production of cage culture in An Giang and Dong Thap provinces 2.3 Proportion of different catfish species in the Mekong Delta in cage production 2.4 Annual production of Pangasius hypophthalmus spp for export in the Mekong Delta, Vietnam 12 3.1 Study Area Map of An Giang Province, Mekong Delta, Vietnam 3.2 Top view of sampling site at the Pangasius hypophthalmus cage and Pen culture 28 3.3 Top view of sampling site at the pond culture 3.4 General view of the field measurement at My Hoa Hung, Long Xuyen city, An Giang province 28 3.5 Mass balances for phosphorus and nitrogen load from cage and pen fish farming 30 3.6 Nutrient budgets of cage, pen and pond 31 3.7 Nutrient budgets of cages in the river 31 4.1 Average ages of fish farmer’s manager in An Giang province 37 4.2 Percentage gender distribution of fish farmer’s manager in An Giang province 37 4.3 Previous occupation of fish farm owner in An Giang province 39 4.4 Cages culture in An Giang province, Mekong River of Vietnam 40 4.5 Pen culture in An Giang province, Mekong River of Vietnam 42 4.6 Pond culture in An Giang province, Mekong River of Vietnam 43 4.7 Kinds of feed used in Pangasius hypophthalmus culture systems 46 4.8 The percentages of fish farming using different ingredients of homemade feed for Pangasius hypophthalmus species in An Giang 47 4.9 The percentages of fish farming using different ingredients of pangasius waste feed for Colossoma macropomum cage culture 49 4.10 Diagram of feed processing for Pangasius hypophthalmus species 50 4.11 Diagram of feed processing for Colossoma macropomum species 50 4.12 Pangasius hypophthalmus feed processing 51 viii 20 28 4.13 Colossoma macropomum feed processing 51 4.14 The ratios of fish farming using the additives in homemade feed 52 4.15 Average initial instruction cost of fish culture systems in An Giang province 54 4.16 The structure of the marketing of channel of fish aquaculture in the Mekong River, Vietnam 56 5.1 General comparison views of water quality parameters in Cages, Pens and culture 60 5.2 General comparison views of water quality parameters in Ponds culture 5.3 Water temperatures in upstream and downstream of cages and pens culture compared to pump-in and pump-out of ponds culture during three seasons 62 5.4 pH levels in upstream and downstream of cages and pens culture compared to pump-in and pump-out of ponds culture during three seasons 63 5.5 DO in upstream and downstream of cages and pens culture compared to pumpin and pump-out of ponds culture during three seasons 64 5.6 TSS in upstream and downstream of cages and pens culture compared to pumpin and pump-out of ponds culture during three seasons 65 5.7 Nitrite-N (NO2; mg/L) concentrations in upstream and downstream of cages and pen culture compared to pump-in and pump-out of ponds culture during three seasons 67 5.8 Nitrate concentrations at upstream and downstream of cages and pens culture as compared with pump-in and pump-out of ponds culture during three seasons 67 5.9 Total nitrogen in upstream and downstream of cages and pens culture as compared with pump-in and pump-out of ponds culture during three seasons 68 5.10 Phosphorous concentrations in upstream and downstream of cages and pens culture as compared with pump-in and pump-out of ponds culture during three seasons 69 ix 60 CHAPTER INTRODUCTION 1.1 Introduction In recent years, aquaculture production has increased worldwide, mainly due to the increasing demand for aquaculture produce, and the need for new food supplies This development generates profit and income, but it also bears risks of negative environmental impact, such as pollution or biodiversity change (Tovar and Moreno, 2000) The main input in most intensive fish culture systems is feed of fish in the form of wet homemade feed, trash fish, and pellets These feeds are partly transformed into fish biomass and partly released into the water as suspended solids or dissolved matter such as carbon, nitrogen and phosphorus These wastes are originating from surplus food, faces and excretions via gills and kidneys Other pollutants are residuals of drugs used to cure or prevent diseases Aquaculture feeds and feeding regimes can play a major role in determining the quality and potential environmental impact or not of finfish and crustacean farm effluents (Tacona and Forster, 2003) This is particularly true for those intensive farming operations employing open aquaculture production systems, the latter including net cages/pens enclosures placed in rivers, estuaries or open-water bodies, raceway or pond production systems This is perhaps not surprising since the bulk of the dissolved and suspended inorganic and organic matter contained within the effluents of intensively managed open aquaculture production systems are derived from feed inputs, either directly in the form of the end-products of feed digestion and metabolism or from uneaten/wasted feed, or indirectly through eutrophication and increased natural productivity An Giang province of Vietnam is one of the provinces in Mekong Delta where many types of intensive fish culture systems i.e fish pond, floating cages and pens, are located An Giang province located on the border to Cambodia is the centre of production (70 to 80 %) of Vietnamese’s Pangasius gigas (Basa fish), Pangasius hypophthalmus (Tra fish) come from this region (FAO, 2005) The number of floating cages in the province increased from 169 in 2003 to 3,568 in 2004 but 3,531 in 2005 decreased 37 pieces There were 1,167 of fish ponds area in 2004 and 1,512 of fish ponds area in 2005 Overall production capacities from these systems were 152,507 tons in 2004 and 232,139 in 2005 (An Giang province statistical yearbook, 2005) Mainly Pangasiusis hypophthalmus (Tra fish) are cultured in floating cages and pens in rivers and canals in An Giang province The total water area for pens culture and Veo (hapa net) culture for this species were 21 and 80 ha, respectively, in 2003 and the area increased up to 32 and 84 ha, respectively, by 2004 and 313 in 2005 (An Giang province statistical yearbook, 2005) The total number of floating cages in total of province increased from 2,126 in 1995 to 3,568 in 2004 These increasing trends might have continued until today Intensive floating cage and pen culture of Pangasius hypophthalmus (Tra fish) have been developed and operated by the indigenous knowledge of local farmers (Tan, 2001) which provides a new significant income source, helping to diversify farming activities, reduce risk, alleviate poverty and provide employment opportunities throughout the year This is very important livelihood activity for landless farmers Floating cage and pen culture in rivers is an intensive operation by nature, have both detrimental and beneficial effect on surrounding environment The major problem areas in river floating fish culture systems are 1) Environment interaction i.e effluent from (For Department of fisheries, Province office, District office) Year Pangasius culture systems 1995 2000 2001 2002 2003 2004 2005 Total area (ha) Total production (tones) + Pond culture + Pen culture + Cages culture Productivity An Giang; ………/…… /2006 Interviewer Name: …………………………… 94 Pump in (1) Pump out (2) (1) (2) Water outflow 1m from cage Water inflow 1m from cage Figure 3.3 Top view of sampling site at the pond culture Figure 3.2 Top view of sampling site at the Pangasius cage and Pen culture 28 Main River (Mekong River) Culture sites of cages, ponds and pens random (Middle stream location) Upstream location km Downstream location km Figure 3.4 General view of the field measurement at My Hoa Hung, Long Xuyen city, An Giang province APPENDICES Appendix A: Socio-technical Aspects of Aquaculture Systems Information Table A1 Technical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam Components Description of Cage of Pangasius (n = 20) Description of Cage of Colossoma (n = 15) Description of Pen Pangasius (n = 20) Description of Pond Pangasius (n = 18) 95 Age of farmers (year old) Ranging from 24 to 54 Average = 39±6.8 Ranging from 21 to 67 Average: 43±12.0 Ranging from 26 to 60 Average = 41.8±9.2 Ranging from 20 to 61 Average = 36±13.6 Gender Women = 15 (%) Men = 85 (%) Men = 100 (%) Women = 10 (%) Men = 90 (%) Women = (%) Men = 100 (%) Illiterates = 10 (%) Primary school = 25 (%) Second primary = 40 (%) High school = 10(%) Bachelor = 15 (%) Illiterates = 10 (%) Primary school = 25 (%) Second primary = 40 (%) High school = 10(%) Bachelor = 15 (%) Illiterates = (%) Primary school = (%) Second primary = 40 (%) High school = 40(%) Bachelor = 20 (%) Illiterates = (%) Primary school = 17 (%) Second primary = 28 (%) High school = 33(%) Bachelor = 16 (%) Run farms & experience (years) Ranging from to 14 Average = 5.2±2.9 Ranging from to Average: 2.4±0.2 Ranging from to Average = 3.8±1.3 Ranging from to 11 Average = 5±2.5 Training times Ranging from to Average = 2.6±1.6 Ranging from to Average: 0.5±0.5 Ranging from to Average = 2.4±2.0 Ranging from to Average = 2.1±1.8 Proprietary Cooperation = 25 (%) Private = 75 (%) Private = 100 (%) Cooperation = 10 (%) Private = 90 (%) Cooperation = 11 (%) Private = 89 (%) No of farmer's system culture (cage, pen, pond) Ranging from to Average = 1.7±1.1 Ranging from to Average: 2.6±2.0 Ranging from to Average = 1.5±1.0 Ranging from to Average = 2.4±2.1 Educational level Table A2 Technical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam Shape Square = (%) Rectangle = 100 (%) Rectangle = 100 (%) Square = 25 (%) Rectangle = 75 (%) Square = 17 (%) Rectangle = 83 (%) Total areas (m2) Ranging from 72 to 450 Average = 182±81 Ranging from 15.6 to 98 Average: 48 ± 23 Ranging from 600 to 14,00 Average = 4,571±3,988 Ranging from 850-3,500 Average = 2,117±789 10 Total Volume (m3) Ranging from 432 to 2,400 Average = 1,216 ± 420 Ranging from 78 to 490 Average: 199 ± 118 Ranging from 1,200 to 42,000 Average = 12,942±11,663 Ranging from 1,700–26,250 Average = 10,209 ±7,537 11 Width (m) Ranging from to 15 Average = 8.4±2.0 Ranging from to Average: 4.7±1.1 Ranging from 15 to 80 Average = 44.8±19.8 Ranging from 20 to 120 Average = 43.2±24.0 Ranging from 12 to 30 Average = 21.2±4.7 Ranging from 5.2 to 14 Average: 9.8±2.7 Ranging from 40 to 200 Average = 91±56.8 Ranging from 40 to 200 Average = 104±61.4 13 Depth (m) Ranging from 4.5 to Average = 6.9±0.9 Ranging from 3.4 to Average: 4.1±0.5 Ranging from to Average = 3.0±0.6 Ranging from to Average = 3.1±0.7 14 Water level in systems Ranging from to 8.0 Average = 6.1±1.1 Ranging from 2.9 to 4.5 Average: 3.6±0.5 Ranging from to Average = 2.7±0.6 Ranging from 1.5 to 3.5 Average = 2.7±0.7 15 Distance from the bank of river to culture systems (m) Ranging from 15 to 300 Average = 122.7±92.3 Ranging from 50 to 200 Average: 122±58.2 Nearness of the river bank Ranging from to 150 Average = 30.6±41.3 16 Distance of between of culture systems (m) Ranging from to 40 Average = 22.2±10.8 Ranging from to 50 Average: 27.5±19.0 Ranging from 15 to 500 Average = 150 Ranging from to Average = 10 12 Length (m) 96 Table A3 Technical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam 17 Source of seed AG Hatchery Center: 60(%) Dong Thap province: 15 (%) Another hatchery in AG: 25 (%) Dong Thap province: 53 (%) Another hatchery in AG: 40 (%) Can Tho province: (%) AG Hatchery Center: 45(%) Dong Thap province: 20 (%) Another hatchery in AG: 35 (%) AG Hatchery Center: 28 (%) Dong Thap province: 22 (%) Another hatchery in AG: 44 (%) and Cambodia: (%) 18 Initial size (cm) Ranging from 2.0 to 3.0 Average = 2.6±0.3 Ranging from 1.4 to 3.0 Average: 2.0±0.4 Ranging from 1.7 to 3.0 Average = 2.35±0.4 Ranging from 1.7 to 3.0 Average = 2.5±0.4 19 Stocking density/ m2 Ranging from 48 to 906 Average = 541±221.9 Ranging from 168 to 900 Average: 658±184 Ranging from 30 to 98 Average = 59.1±20.2 Ranging from 27 to 99 Average = 61±25.0 Ranging from to 121 Average = 78±30.3 Ranging from 130 to 270 Average: 195±42 Ranging from 10 to 67 Average = 25.5±11.9 Ranging from 12 to 70 Average = 32±16.3 21 Total of seed (fish) (12,000 to 155,000) 85,700±32,003 (13,000 to 100,000) 41,533±21,886 (25,000 to 400.000) 177,250±105,712 (45,000 to 500,000) 200,889±154,984 22 Seed price (VND) From 260 to 1,800 Average = 1,056±444 From 100 to 400 Average: 186±97.5 From 320 to 1,050 Average = 632.5±151.7 From 250 to 1,050 Average = 627±205 23 Total cost of seed (VND) (15,600,000 to 201,500,000) 87,150,000±47,202,760 (1,365,000 to 18,000,000) 7,447,667±4,550,900 (14,500,000 to 240,000,000) 111,6550,000±63,585,487 (26,100,000 to 281,250,000) 113,456,111±79,424,957 24 Culture Period (month) Ranging from to Average = 5.6±0.51 Ranging from 4.5 to 6.0 Average: 4.8±0.4 Ranging from to Average = 6±0.6 Ranging from 4.5 to Average = 5.9±0.72 25 Feed kind Homemade = 85 -90 (%) Pellet feed = 10 -15 (%) Pellet feed & Homemade feed 100 (%) Homemade = 40 (%) Pellet feed = 60 (%) Homemade = 16 (%) Pellet feed = 84 (%) 20 Stocking density/ m3 97 Table A4 Technical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam Homemade feed (cooked) Pellet feed (proconco (40 %), carrgill, Mekong feed, aquagreen, aquaxcel feedand made by themseft ) 26 Feed name Homemade feed (80 %) Pangasius waste feed (100%) Homemade feed (cooked) Pellet feed (proconco (40 %), carrgill, Mekong feed and made by themseft) 27 Total feed (kg) (110,000 to 366,000) 212,845±63,209 (14,300 to 148,500) 53,617±35,311 (40,500-597,000) 247,590±128,045 (81,000 to 322,000) 210,289±69,038 28 Feed price (VND) (2,500 to 6,000) 3,563±852.6 1,200 to 2,100 1,680±245.5 (3,500 to 6,000) 4,890±1,086 (2,500 to 6,400) 4,742±1,081 29 Total cost of feed (VND) (385,000,000 to1,248,000,000) 744,013,605±223,374,809 (22,880,000 to 252,450,000) 90,972,633±62,463,397 (243,000,000 to 3,283,500,000) 1,208,427,500±721,829,886 (340,200,000 to 1,674,400,000) 987,586,111±368,179,230 times = 100 (%) times = 73 (%) times = 100 (%) times = 100 (%) 31 Harvesting Method Seine = 100 (%) Seine = 100 (%) Seine = 100 (%) Seine = 72 (%) Seine & pump = 28 (%) 32 Harvest times time = 100 (%) time = 100 (%) time = 60 (%) times = 25 (%) Many times = 15 (%) time = 39 (%) times = 39 (%) Many times = 22 (%) 33 Total of yield (production) kg/cage (48,500 to 120,000) (76,620±21,397) (5,700 to 60,000) 21,447±13,134 (30,000 to 300,000) 122,950±70,464 (30,000 to 147,000) 93,444±33,870 34 Price for sale (VND) Ranging from 11,000 to 13,700 Average = 12,445±932.7 Ranging from 5,500 to 6,300 Average: 5,887±250.3 Ranging from 11,000 to 13,500 Average = 12,850±709 Ranging from 11,000 to 18,000 Average = 13,278±1,487 30 Feeding times 98 Table A5 Technical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam (405,000,000 to 4,050,000,000) 1,587,600,000±933,125,035 (405,000,000 to 1,9840,000,500) 1,253,277,778±503,703,000 Ranging from 800 to 2,000 Average: 1,200±300 Ranging from 1,200 to 2,000 Average = 1,420±226.2 Ranging from 1,200 to 2,000 Average = 1,444±250 Ranging from 500 to 800 Average = 620±105.6 Ranging from 500 to 3000 Average: 353±81.2 Ranging from 400 to 1,000 Average = 660±160.3 Ranging from 400 to 1,000 Average = 644±165 Ranging from 1,000 to 1,200 Average = 1,065±87.5 Ranging from 700 to 300 Average: 529±134.1 Ranging from 1,000 to 1,200 Average = 1,065±87.5 Ranging from 1,000 to 1,200 Average = 1,083±92.0 39 Wholesaler AGFISH factory = 65 (%) NAMVIET factory = (%) QVD factory = (%) NAVICO factory = (%) CATACO factory = (%) MEKONG factory = 15 (%) Customers in Mekong Delta AGFISH factory = 50 (%) NAMVIET factory = 30 (%) QVD factory = (%) NAVICO factory = (%) CATACO factory = (%) MEKONG factory = (%) AGFISH factory = 55 (%) NAMVIET factory = 35 (%) CATACO factory = (%) MEKONG factory = (%) 40 Market Export = 100 (%) Domestic = 100 (%) Export = 100 (%) Export = 100 (%) 41 FCR Ranging from 2.1 to 3.6 Average = 2.8±0.4 Ranging from 1.9 to 3.5 Average: 2.5±0.5 Ranging from 1.4 to 2.5 Average = 2.0±0.4 Ranging from 1.4 to 3.0 Average = 1.8±0.4 35 Total cost return (VND) (630,500,000 to 1,620,000,000) 966,005,000±286,796,705 36 Maximum weight in harvesting (g/fish) Ranging from 1,200 to 2,000 Average = 1,420±185.2 37 Minimum weight in harvesting (g/fish) 38 Average weight in harvesting (g/fish) (31,350,000 to 378,000,000) 127,570,000±82,831,744 99 Appendix B: Economic Aspects of Aquaculture Systems Information Table B1 Economical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam Economic Description of Cage of Pangasius (n = 20) Initial construction cost (VND) (150,000,000 to 550,000,000) 258,300,000±94771248 (30,000,000 to 300,000,000) 102,666,667±77,318,143 (35,000,000 to 300,000,000) 161,434,500±76,517,529 (35,000,000 to 230,000,000) 130,316,667±64884788 Total of seed (fish) (12,000 to 155,000) 85,700±32,003 13,000 to 100,000 41,533±21,866 25,000 to 400.000 177,250±105,712 45,000 to 500,000 200,889±154,984 (260 to 1,800) 1,056±444 (100 to 400) 186±97.5 (320 to 1,050) 632.5±151.7 (250 to 1,050) 627±205 Total cost of seed (VND) (15,600,000 to 201,500,000) 87,150,000±47202760 (1,365,000 to 18,000,000) 7,447,667±4,550,900 (14,500,000 to 240,000,000) 111,6550,000±63,585,487 (26,100,000 to 281,250,000) 113,100,000±79,424,957 Total feed (kg) (110,000 to 366,000) 212,845±63,209 (14,300 to 148,500) 53,484±35,311 (40,500 to 597,000) 247,590±128,419 (51,000 to 267,000) 170,894±69,038 Feed price (VND) (2,500 to 6,000) 3,563±852.6 (1,200 to 2,100) 1,680±245.5 (3,500 to 6,000) 4.890±1,086 (2,600 to 6,400) 4.874±1,081 Total cost of feed (VND) (385,000,000 to 1,248,000,000) 744,013,605±233,374,809 (22,880,000 to 252,450,000) 90,705,000±62,463,397 (243,000,000 to 3,283,500,000) 1,208,427,500±721,829,886 (214,200 to 1,478,400,000) 825,767,647±368,179,230 Total of labor and management (9,600,000 to 63,000,000) 26,910,000±15,049,844 (525,000 to 24,000,000) 5,815,000±587,427 (6,500,000 to 45,000,000) 22,295,000±10,608,957 (6,000,000 to 29,400,000) 133,666,667±7,163,233 Seed price (VND) Description of Cage of Colossoma (n = 15) Description of Pen Pangasius (n = 20) Description of Pond Pangasius (n = 18) 100 Table B Economical Aspects of Aquaculture Systems in An Giang Province, Mekong River in Vietnam 101 Total medicine cost (10,000,000 to 66,000,000) 31,274150±14,527,531 (1,500,000 to 30,000,000) 5,353,333±7,004,169 (15,000,000 to 100,000,000) 57,550,000±29,683,373 (10,000,000 to 100,000,000) 46,555,556±27,861,469 10 Total electricity and gasoline cost (1,500,000 to 20,000,000) 11,710,526±5,603,362 (960,,000 to 4,500,000) 1,076,568±1,076,568 (2,500,000 to 45,000,000) 18,742,737±11,511,547 (2,500,000 to 43,000,000) 15,241,882± 11 Total of yield (production) kg 48,500 to 120,000 76,620±21,397 1,700 to 60,000 21,447±13,134 20,000 to 300,000 123,300±70,464 20,000 to 300,000 123,300±33,780 12 Price for sale (VND) (11,000 to 13,700) 12,445±862.4 (5,500 to 6,300) 5,887±250 (11,000 to 13,500) 12,850±568 (11,000 to 18,000) 13,2780±1,487 13 Total cost return (VND) (630,500,000 to 1,620,000,000) 966,005,000± (42,000,000 to 378,000,000) 130,503,333±79,908,404 (405,000,000 to 4,050,000,000) 1,613,600,000±933,125,035 (405,000,000 to 1,984,500,000) 1,253,277,778±503,703,000 14 Total Initial investment cost (VND) (499,600,000 to 1426000000) 884,396,075±252,940,893 (33,587,500 to 318,850,000) 117,947,717±72927580 (274,200,000 to 274,200,000) 1,441,738,100±844,325,301 (269,100,000 to 1,623,500,000) 965,801,556±299,730,861 14 Total benefic cost (VND) Money losse:34 (%) (20,125,500 to 174,600,000) 74,862,167 Money gain: 67 (%) (15,800,000 to 329,200,000) 81,608,925 Money losses: 27 (%) (8,647,500 to 13,912,500) 11,427,813 Money gain: 73 (%) (33,587,500 to 59,150,000) 12,555,617 Money losses: (%) Money gain: 100 (%) (48,000,000 to 734,200,000) 231,861,900 Money losses: 22 (%) (13,612,000 to 219,500,000) 116,340,500 Money gain: 78 (%) (105,700,000 to 1,342,800,000) 402,852,429 Appendix C: Water Quality Parameters of Aquaculture Systems in An Giang province, Mekong River in Vietnam Appendix C1: Water Quality Parameters of Aquaculture Systems in August, 2006 Cages Ponds Pens Parameters 102 Inflow Outflow Pump-in Pump-out Inflow Outflow Temperature (°C) (0.5 m, 1.5 m and 2.5 m) 27.0±0.28 (26.7-27.3) 26.6±0.98 (25.6-27.5) 27.8±0.51 (27.5-28.4) 27.4±0.48 (26.9-27.9) 27.7±0.44 (27.4-28.2) 26.7±0.96 (25.6-27.5) pH (0.5 m, 1.5 m and 2.5 m) 6.9±0.2 (6.7-7.0) 6.8±0.5 (6.2-7.1) 6.5±0.1 (6.4-6.7) 6.4±0.3 (6.1-6.7) 7.0±0.3 (6.8-7.3) 6.8±0.5 (6.3-7.3) DO (mg/L) (0.5 m, 1.5 m and 2.5 m) 8.08±0.2 (7.99-8.26) 7.97±0.15 (7.85-8.14) 8.22±0.52 (7.61-8.55) 7.64±0.49 (7.08-79.8) 7.65±0.22 (7.41-7.86) 7.93±0.33 (7.74-8.31) TSS (mg/L) (0.5 m, 1.5 m and 2.5 m) 95.3±26.3 (75.0-125.0) 94.1±21.0 (77.5-117.7) 54.0±4.19 (49.2-56.8) 82.7±52.8 (25.8-129.2) 54.4±32.2 (20.2-84.0) 77.4±16.6 (64.0-96.0) NO2 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.05±0.01 (0.04-0.06) 0.14±0.15 (0.04-0.32) 0.20±0.26 (0.05-0.50) 0.25±0.24 (0.10-0.52) 0.05±0.01 (0.04-0.05) 0.06±0.001 (0.05-0.06) NO3 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.20±0.02 (0.19-0.22) 0.32±0.27 (0.14-0.64) 0.18±0.04 (0.15-0.22) 0.21±0.07 (0.13-0.26) 0.29±0.09 (0.24-0.39) 0.28±0.07 (0.22-0.35) TN (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.311±0.056 (0.246-0.348) 0.351±0.031 (0.316-0.371) 0.191±0.055 (0.155-0.254) 0.382±0.096 (0.284-0.476) 0.289±0.139 (0.167-0.440) 0.349±0.137 (0.176-0.523) TP (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.660±0.097 (0.549-0.726) 0.862±0.091 (0.757-0.917) 0.763±0.063 (0.695-0.819) 1.556±0.496 (1.085-2.074) 0.490±0.313 (0.163-0.787) 0.543±0.221 (0.318-0.760) Appendix C2: Water Quality Parameters of Aquaculture Systems in October, 2006 Cages Ponds Pens Parameters 103 Inflow Outflow Pump-in Pump-out Inflow Outflow Temperature (°C) (0.5 m, 1.5 m and 2.5 m) 26.7±0.16 (26.5-26.8) 26.8±0.17 (26.6-27.0) 27.0±0.13 (26.9-27.1) 27.0±0.22 (26.9-27.3) 27.2±0.10 (27.1-27.3) 27.5±0.13 (27.3-27.6) pH (0.5 m, 1.5 m and 2.5 m) 6.6±0.65 (6.1-7.3) 6.5±0.02 (6.5-6.5) 6.5±0.51 (5.9-6.9) 6.4±0.13 (6.3-6.5) 6.3±0.61 (5.9-7.0) 5.9±0.34 (5.5-6.1) DO (mg/L) (0.5 m, 1.5 m and 2.5 m) 8.9±0.26 (7.9-8.4) 7.9±0.55 (7.6-8.6) 7.8±0.44 (7.4-8.3) 7.4±0.25 (7.2-7.7) 7.8±0.10 (7.7-7.9) 7.6±0.16 (7.5-7.8) TSS (mg/L) (0.5 m, 1.5 m and 2.5 m) 20.4±1.25 (19.3-21.8) 20.0±1.60 (18.2-21.4) 14.0±16.6 (1.03-32.8) 7.38±1.60 (1.07-17.5) 7.6±1.6 (5.8-8.7) 10.3±2.77 (7.9-13.4) NO2 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.004±0.001 (0.003-0.006) 0.023±0.010 (0.012-0.031) 0.017±0.003 (0.014-0.020) 0.020±0.006 (0.014-0.026) 0.009±0.006 (0.002-0.014) 0.012±0.003 (0.009-0.016) NO3 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.141±0.029 (0.108-0.165) 0.161±0.055 (0.107-0.217) 0.082±0.032 (0.045-0.105) 0.213±0.176 (0.111-0.417) 0.137±0.028 (0.115-0.168) 0.154±0.029 (0.187-0.187) TN (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.27±1.17 (0.17-0.47) 0.23±0.404 (0.00-0.700) 2.29±2.08 (0.98-4.68) 2.71±3.46 (0.37-6.68) 0.146±0.22 (0.003-0.40) 0.156±0.126 (0.07-0.300) TP (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.056±0.041 (0.011-0.090) 0.088±0.048 (0.042-0.138) 0.080±0.065 (0.037-0.155) 0.155±0.042 (0.107-0.185) 1.63±2.108 (0.211-4.056) 0.929±1.431 (0.000-2.577) Appendix C3:Water Quality Parameters of Aquaculture Systems in December, 2006 Cages Ponds Pens Parameters 104 Inflow Outflow Pump-in Pump-out Inflow Outflow Temperature (°C) (0.5 m, 1.5 m and 2.5 m) 28.1±0.74 (27.5-27.9) 29.2±0.35 (28.9-29.6) 28.8±0.72 (28.0-29.2) 29.8±0.25 (29.6-30.1) 30.3±1.14 (29.5-31.6) 30.8±1.30 (30.1-32.3) pH (0.5 m, 1.5 m and 2.5 m) 7.7±0.14 (7.6-7.87) 7.6±0.04 (7.6-7.7) 6.97±0.06 (6.9-7.0) 6.9±0.02 (6.93-6.97) 7.6±0.20 (7.4-7.8) 7.6±0.13 (7.5-7.8) DO (mg/L) (0.5 m, 1.5 m and 2.5 m) 8.04±0.28 (7.85-8.37) 7.87±0.20 (7.63-8.00) 7.82±0.29 (7.57-8.13) 7.81±0.05 (7.77-7.87) 7.88±0.016 (7.70-8.00) 8.0±0.2 (7.80-8.2) TSS (mg/L) (0.5 m, 1.5 m and 2.5 m) 15.9±8.0 (9.0-24.7) 13.8±3.6 (9.7-16.4) 39.3±8.3 (32.2-48.3) 32.6±10.7 (23.0-44.2) 19.6±7.7 (11.3-26.7) 21.6±2.8 (18.3-23.7) NO2 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.006±0.001 (0.005-0.007) 0.030±0.013 (0.015-0.039) 0.019±0.002 (0.017-0.020) 0.024±0.008 (0.016-0.033) 0.012±0.002 (0.010-0.015) 0.012±0.003 (0.010-0.015) NO3 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.147±0.021 (0.124-0.163) 0.159±0.055 (0.108-0.217) 0.110±0.045 (0.065-0.154) 0.286±0.238 (0.111-0.557) 0.149±0.033 (0.129-0.188) 0.155±0.029 (0.130-0.187) TN (mg/L) (0.5 m, 1.5 m and 2.5 m) 1.949±1.181 (0.951-3.254) 3.385±0.759 (2.601-4.116) 2.722±1.988 (1.517-5.017) 2.964±3.818 (0.377-7.350) 2.623±0.676 (2.173-3.401) 2.837±2.854 (0.233-5.888) TP (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.310±0.248 (0.127-0.501) 0.155±0.160 (0.0420-0.338) 26.726±15.073 (17.237-44.106) 27.602±14.521 (16.984-44.149) 1.634±2.108 (0.211-4.056) 0.929±1.431 (0.000-2.577) Appendix D: Water Quality Parameters in Aquaculture Systems in Three Seasons Table D1: Water Quality Parameters in Cages Culture Cages (August, 2006) Cages (October, 2006) Cages (December, 2006) Parameters 105 Inflow Outflow Downstream Inflow Outflow Downstream Inflow Outflow Downstream Temperature (°C) (0.5 m, 1.5 m & 2.5 m) 26.9±0.20 27.1±0.19 26.6±0.8 26.7±0.16 26.8±0.17 26.7 ± 0.41 27.4±0.20 27.8±0.60 29.4±0.05 pH (0.5 m, 1.5 m & 2.5 m) 6.9±0.18 6.8±0.5 6.9 ± 0.10 6.6±0.65 6.5±0.02 6.9 ± 0.1 7.1±0.14 7.1±0.04 7.3±0.04 DO (mg/L) (0.5 m, 1.5 m & 2.5 m) 8.1±0.2 7.6±0.5 7.3 ± 0.3 8.0±0.3 7.4±0.2 6.7 ± 0.3 8.0±0.3 7.1±0.2 7.3 ± 0.3 95.3±26.3 134.2±0.12 170.1±27.9 20.4±1.25 20.0±1.60 81.9 ± 31.1 52.8±23.2 62.4±18.46 88.0 ± 22.3 NO2 (mg/L) (0.5 m, 1.5 m & 2.5 m) 0.05±0.01 0.14±0.15 0.16 ± 0.01 0.004±0.001 0.025±0.008 0.02 ± 0.00 0.006±0.001 0.070±0.050 0.17 ±0.01 NO3 (mg/L) (0.5 m, 1.5 m & 2.5 m) 0.2±0.02 0.3±0.27 1.13 ± 0,22 0.41±0.029 0.47±0.500 1.10 ± 0.13 0.147±0.021 0.159±0.055 0.95 ± 0.13 TN (mg/L) (0.5 m, 1.5 m & 2.5 m) 0.311±0.056 0.351±0.031 0.849±0.000 0.27±1.17 0.35±0.363 1.14 ± 0.17 1.949±1.181 3.385±0.759 3.389±0.750 TP (mg/L) (0.5 m, 1.5 m & 2.5 m) 0.660±0.097 0.862±0.091 1,39 ± 0,27 0.06±0.041 0.09±0.05 1.20 ± 0.29 0.310±0.248 0.155±0.160 1.60 ± 0.56 TSS (mg/L) (0.5 m, 1.5 m & 2.5 m) Table D2: Water Quality Parameters in Pens Culture Pens (August, 2006) Pens (October, 2006) Pens (December, 2006) Parameters Inflow Outflow Downstream Inflow Outflow Downstream Inflow Outflow Downstream Temperature (°C) (0.5 m, 1.5 m & 2.5) 27.7±0.44 26.7±0.96 26.6±0.8 27.2±0.10 27.5±0.13 26.7 ± 0.41 30.3±1.14 30.8±1.30 29.4±0.05 pH (0.5 m, 1.5 m & 2.5) 6.9±0.27 6.8±0.5 6.9 ± 0.10 6.3±0.61 5.9±0.34 6.9 ± 0.1 7.6±0.20 7.6±0.13 7.3±0.04 DO (mg/L) (0.5 m, 1.5 m & 2.5) 7.65±0.22 7.93±0.33 7.3 ± 0.3 7.8±0.10 7.6±0.16 6.7 ± 0.3 7.88±0.016 8.0±0.2 7.3 ± 0.3 54.4±32.2 77.4±16.6 170.1±27.9 7.6±1.6 10.3±2.77 81.9 ± 31.1 19.6±7.7 21.6±2.8 88.0 ± 22.3 NO2 (mg/L) (0.5 m, 1.5 m & 2.5) 0.05±0.01 0.06±0.001 0.16 ± 0.01 0.009±0.006 0.012±0.003 0.02 ± 0.00 0.012±0.002 0.012±0.003 0.17 ±0.01 NO3 (mg/L) (0.5 m, 1.5 m & 2.5) 0.29±0.09 0.28±0.07 1.13 ± 0,22 0.137±0.028 0.154±0.029 1.10 ± 0.13 0.149±0.033 0.155±0.029 0.95 ± 0.13 TN (mg/L) (0.5 m, 1.5 m & 2.5) 0.289±0.139 0.349±0.137 0.849±0.000 0.146±0.22 0.156±0.126 1.14 ± 0.17 2.623±0.676 2.837±2.854 3.389±0.750 TP (mg/L) (0.5 m, 1.5 m & 2.5) 0.490±0.313 0.543±0.221 1,39 ± 0,27 1.63±2.108 0.929±1.431 1.20 ± 0.29 1.634±2.108 0.929±1.431 1.60 ± 0.56 TSS (mg/L) (0.5 m, 1.5 m & 2.5) 106 Table D3: Water Quality Parameters in Ponds Culture Parameters Ponds (August, 2006) Ponds (October, 2006) Ponds (December, 20006) 107 Pump-in Pump-out Pump-in Pump-out Pump-in Pump-out Temperature (°C) (0.5 m, 1.5 m and 2.5 m) 27.8±0.51 27.4±0.48 27.0±0.13 27.0±0.22 28.8±0.72 29.8±0.25 pH (0.5 m, 1.5 m and 2.5 m) 6.5±0.14 6.4±0.3 6.5±0.51 6.4±0.13 6.97±0.06 6.9±0.02 DO (mg/L) (0.5 m, 1.5 m and 2.5 m) 8.2±0.5 7.6±0.5 7.8±0.4 7.1±0.2 7.8±0.2 7.5±0.05 TSS (mg/L) (0.5 m, 1.5 m and 2.5 m) 54.0±4.19 82.7±52.8 14.0±16.6 7.38±1.60 39.3±8.3 32.6±10.7 0.20±0.26 0.25±0.24 0.017±0.003 0.020±0.006 0.019±0.002 0.024±0.008 NO3 (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.18±0.04 0.21±0.07 0.082±0.032 0.213±0.176 0.110±0.045 0.286±0.238 TN (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.191±0.055 0.382±0.096 2.29±2.08 2.71±3.46 2.722±1.988 2.964±3.818 TP (mg/L) (0.5 m, 1.5 m and 2.5 m) 0.763±0.063 1.556±0.496 0.080±0.065 0.155±0.042 26.726±15.073 27.602±14.521 NO2 (mg/L) (0.5 m, 1.5 m and 2.5 m) ... RESUTLS The Socio-technical survey of aquaculture systems in An Giang province 4.1 General information 4.1.1 Geographical location of Mekong River of Vietnam The Mekong River is the longest river in. .. and others fish species in rivers An Giang province, Vietnam 1.2 General objective The general objective is to assess the feed use in aquaculture systems on and in the vicinity of Mekong River. .. province 39 4.4 Cages culture in An Giang province, Mekong River of Vietnam 40 4.5 Pen culture in An Giang province, Mekong River of Vietnam 42 4.6 Pond culture in An Giang province, Mekong River