Coastal Shrimp Aquaculture in Thailand: Key Issues for Research

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$%Table 12. (cont’d) Impediments to the development of a sustainable shrimp farming industry in Thailand and the research into these impediments, or the measurestaken to address them.Category Impediments to a sustainable shrimp aquaculture industry Current or recent research in Thailand, or remediation measure aProduction %! Prevalence of high stocking densities.%! Need to improve pond management practices.%! Lack of a method for determining a pond’s carrying capacity.%! Absence of integrated or mixed species farms.%! Reliance on Penaeus monodon in intensive farming.Economic %! Need for economic assessments of the reduction in agriculturalland, including salinisation and direct conversion to shrimp farms.%! Need for economic assessments and management strategies forthe industry with consideration of social and environmentalissues.%! Tendency of farmers to look at short-term profit rather than at sustained,long-term production.%! Lack of evaluation of the economic impact of mangrove andwetland conversion.Social %! Need for assessment of socio-cultural impacts of shrimp farmdevelopment.%! Need for an assessment of conflicts between shrimp farmers andother resource users, and strategies to resolve conflicts.%! Need to improve access of information to members of the publicon the issues affecting shrimp farming (currently lacking, with theexception of occasional newspaper articles).%! Aquastar are currently deciding what stocking density to recommendto farmers which will compensate for their tendencyto stock above recommended levels (D. Fegan, pers. comm.).%! Aquastar is investigating the use of alternative species.%! There has been a study of a single area by Jitsanguan et al.(1993) using some environmental values.%! Study by Bannarlung (1990), Kasetsart University, of theforegone economic benefits of mangrove products whenforests are cleared for shrimp farms.%! Sirisup (1988) studied Chantaburi Province.%! Some study of particular locations by postgraduate universitystudents.General %! Need for farmer cooperatives which have the potential to bringabout the formulation of solutions to regional problems.%! DOF has organised a small proportion of farmers into cooperativegroups.a These were identified by reviewing current literature and from information given by representatives of the listed research organisations. b This Institute has a series of ongoingprojects in Thailand. c Marine Resources Assessment Group, Imperial College, London. (Thai study by Ms V. Cowan.)
There is also a distinct need for a thorough investigation of the bacterial populationsof ponds that break down metabolites, chemicals and solid wastes. The developmentand maintenance of healthy populations of beneficial micro-organisms mayprovide an effective and cheap method of in-pond water treatment. The effects ofroutine use of antibiotics and chemicals such as lime and chlorine on the populationsof these bacteria requires investigation. Furthermore, research is needed into the roleof the maintenance of particular microbe populations in preventing the proliferationof pathogenic microbes. Simple ecological manipulations of microbial populationscould provide a tool for the control of some pathogens.A further area of research that has been largely neglected is the level of chemicalpollutants in source water. The collapse of the shrimp farming industry in the Gulf ofThailand in 1988 was attributed in part to the presence of industrial and agriculturalpollutants in the waters supplying farms. High levels of some pesticides were foundin the waters of Rayong Province in 1990 when extensive, acute shrimp mortalitiesoccurred (Anon. 1994d). However, no comprehensive studies have been performedto determine chemicals present in most areas, nor assessment of the effect of suchcompounds on shrimp health or growth.The occurrence of ‘red tides’ in the Gulf of Thailand requires study. Theseprevent farm water exchange and consequently bring about a deterioration in pondwater quality which compromises shrimp health. There is a need for research into thereasons for these phytoplankton blooms, and for prediction of their occurrence andduration so that farmers can coordinate water exchange.The development of ‘closed systems’ where water is recycled is currently receivingmuch attention and is seen by many as a means of overcoming problems of pollutionof the external water supply and avoiding the effects of red tides. However, thesesystems will always rely on the input of some water to compensate for evaporativeand seepage losses and to counteract hypersalinity induced by evaporation. Therefore,source water of reasonable quality will continue to be important, particularly atintensive stocking densities.EffluentThe discharge of untreated effluent water into receiving waters can cause hypernutrificationand self-pollution of farms. This can be overcome by the developmentof effective water treatment methods. Settlement ponds are recommended by DOFfor water treatment. However, more comprehensive studies are needed to assess theefficiencies of these ponds in removing nutrients, suspended material and farm chemicals.Studies need to examine the appropriate sizes and depths of such ponds and theoptimal retention times for water of different qualities. If they are proven to be effective,research is also needed to determine how these ponds could be incorporated intoexisting farms, especially into small farms which make up the majority of Thailand’sproduction units. Research into appropriate engineering methods to service clustersof these small farms may be useful.There has been, and continues to be, research into biological methods of effluentwater treatment. However, this seems to have been directed toward large-scale experimentsexamining a fairly limited range of species. Despite the recognised shortcomingsof species already examined, there seems to be few attempts to assess the$&
Page 8 and 9: !The 1994 Workshop had a working hy
Page 11 and 12: !The Workshop at Hat Yai, SongkhlaA
Page 13 and 14: !ReferenceSmith, P.T., ed.. 1999. T
Page 15 and 16: !Shrimp Farming in ThailandOver the
Page 18 and 19: ! !Table 1. World production (# 1,0
Page 20 and 21: !Domestic and world demandJapan is
Page 22 and 23: !Intensification of farms has been
Page 24 and 25: !no significant difference between
Page 26 and 27: !Production Practices and Technique
Page 28 and 29: !use water which is almost fresh (F
Page 30 and 31: !mended quantities for application
Page 32 and 33: !the biological processes in sedime
Page 34 and 35: !factors (Fegan 1994). Environmenta
Page 36 and 37: !Acid sulphate soils occur in most
Page 38 and 39: during the rainy season, some deter
Page 40 and 41: Land subsidenceCoastal land subside
Page 42 and 43: first when an area becomes environm
Page 44 and 45: !Administration. Their work has inv
Page 46 and 47: agriculture, selects coastal land p
Page 48 and 49: Sustainability, Sustainable Develop
Page 50 and 51: cultural and environmental asset va
Page 52 and 53: $+Table 12. (cont’d) Impediments
Page 54 and 55: $#Table 12. (cont’d) Impediments
Page 58 and 59: capacities of alternative organisms
Page 60 and 61: sources. This is one of the greates
Page 62 and 63: Table 13. (cont’d) Summary of the
Page 64 and 65: Boonyapiwat, S. 1989. Species of ph
Page 66 and 67: Katesombun, B. 1992. Aquaculture pr
Page 68 and 69: Sirisup, S. 1988 Socio-economic cha
Page 70 and 71: !In the preliminary analysis, the s
Page 72 and 73: !until all variables had been teste
Page 74 and 75: !quality problem over the past 3 ye
Page 76 and 77: !Figure 1. Characterisation of prov
Page 78 and 79: !Variables Contributing to Shrimp P
Page 80 and 81: !Figure 5. Relationship between ave
Page 82 and 83: !southern). The linear regression m
Page 84 and 85: !Appendix. Results of logistic regr
Page 86 and 87: !2) Trat ProvinceClassification tab
Page 88 and 89: !Chi-square df significanceModel Ch
Page 90 and 91: !8) Satun ProvinceClassification ta
Page 92 and 93: !Variables in the equationConstant
Page 94 and 95: !A total of 49 participants were in
Page 96 and 97: ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !Fi
Page 98 and 99: !All issues are listed in Appendice
Page 100 and 101: !!were short term and one issue was
Page 102 and 103: !reared broodstock (issue 71). They
Page 104 and 105: !!Two participants commented that i
Page 106 and 107:
mation transfer and training. This
Page 108 and 109:
108Appendix 1. (cont’d) Descripti
Page 110 and 111:
Page 112 and 113:
112Appendix 2. Descriptive statisti
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Appendix 5. (cont’d) Descriptive
Page 124 and 125:
Appendix 7. Descriptive statistics
Page 126 and 127:
Appendix 7. (cont’d) Descriptive
Page 128 and 129:
Page 130 and 131:
!ParticipantsAustraliaDr Paul T. Sm
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