An integrated planning and management framework for the sustainable development of shrimp farming in Kung Krabaen Bay, Chanthaburi Province, Thailand | |
| Author | Kanokporn Boonsong |
| Call Number | AIT Diss. no.SR-97-01 |
| Subject(s) | Sustainable agriculture--Thailand--Chanthaburi Shrimp culture--Thailand--Chanthaburi |
| Note | A dissertation in partial fulfilment of the requirements for the degree of Doctor of Technical Science |
| Publisher | Asian Institute of Technology |
| Abstract | Thailand has recently become the largest producer of black tiger prawn (Penaeus monodon). However, such intensive marine shrimp farming without proper planning and management has resulted in several problems such as water pollution, destruction of mangrove forest and conflicts of land and water resource among various user groups. Thus, this research develops a framework for integrated planning and management for the overall sustainability of shrimp farming. The integrated approach of resource planning and management in the coastal environment was applied using Kung Krabaen Bay, Chanthaburi Province, Thailand, as the pilot testing site. Kung Krabaen Bay, a semi-enclosed bay of about 640 ha, is under the control and supervision of the Kung Krabaen Bay Royal Development Study Centre which promotes small-scale intensive shrimp farming since 1986 in order to increase farmers' income while simultaneously undertaking both the conservation and restoration of the deteriorated mangrove forests. Following the success of shrimp farms under the Centre, many more private individual farms emerged. As an outcome of over expansion of the shrimp farm given these limited land and water resources and unsustainable shrimp farming practices, a set of interrelated problems have occurred which needed to be addressed and remedied. This study assesses and reviews the current situation of shrimp farming practices and management, relevant bio-physical environmental aspects (e.g. coastal water, mangrove forest and soil/sediment), and the socio-economic setting in the study area, particularly inherent potentials and problems. Based on the findings from such review and assessment, various recommendations for integrated planning and management of shrimp farms have been proposed for their sustainable development. The results of this study reveal that the total area of shrimp pond (water surface area) is approximately 140.8 ha (94.4 ha are ponds under the Centre and 46.4 ha are private). The wastes which are being discharged from these ponds during the culture period are estimated at 27.1 tons N/yr, 5.1 tons P/yr and 2407. 7 tons sediment/yr. After each crop, there are also accumulated sediment at the pond bottom which are cleaned by employing high pressure hose. The estimated quantity of accumulated sediment is as high as 75,162 tons/yr, with these sediments containing 70.6 tons N/yr and 11.7 tons P/yr. It is concluded that the management of accumulated sediment is the major problem that has to be addressed to reduce the adverse impact on the coastal environment. As for the study aspects relating to mangrove forests, the total area of 176 ha Rhizophora dominated forest has been estimated as capable of absorbing 28. 75 tons N/yr and 3. 90 tons P /yr. The first order estimation of the ratio of mangrove forest area to shrimp pond area required to remove nitrogen and phosphorus generated by the shrimp ponds were calculated in 2 cases. In the first case where all wastes (both during culture period and during cleaning pond bottom) are discharged into the coastal environment, the ratio of shrimp pond area : mangrove area should be maintained at approximately 1: 5.4. For the second case where the accumulated sediment at the pond bottom are well managed and are therefore not lost into the coastal environment, the ratio of shrimp pond area : mangrove area should be maintained at approximately 1 : 1. 6. The study on coastal water quality indicates that the volume of water flow at the mouth of the bay is very high, i.e., 15.55 x 106 m3 /12 hr during the wet season and 11.02 x 106 m 3 /12 hr during the dry season. The flushing time (the time period for seawater inside the bay to be replaced with seawater outside the bay) is 0.65 days during the wet season and 0.92 days during the dry season. As a consequence, the water inside and outside the bay are well mixed, resulting in good seawater quality especially near the mouth of the bay. This conclusion is supported by the calculation result pertaining to the carrying capacity of the bay using ammonia-nitrogen as a criterion. Such result indicates that the expansion area of shrimp farming can extend up to 563 ha. However, this estimation was calculated only for the wet season. For the dry season scenario, lower carrying capacity is expected. Thus, the further study of the carrying capacity during the dry season is recommended. It should be noted though that the monitoring results of the Department of Fisheries reveal that there is already some extent of water quality deterioration, especially near the shore where the farmers pump water into their ponds. This is further confirmed by the results of hydrographic sampling over 2 tidal cycles during the wet and dry season that the low dissolved oxygen concentration (< 4 mg/L) are indicative of poor water quality at the mouth of the canal, especially during the low tide period. Given the current situation of shrimp farming practices and management in the context of Kung Krabaen Bay coastal environment, there are a variety of problems/issues that have to be addressed. These major planning and management issues on shrimp farming and impact on bio-physical environment include: (1) Unsustainability of shrimp farming as manifested by the higher frequent disease outbreak, the occurrence of new disease and the pollution problem; (2) Deterioration of coastal water quality and rapid sedimentation and accumulation of waste in canal system as a result of the high amount of wastes from shrimp farming that are being discharged into coastal environment; (3) The maintenance of the optimum balance in area between shrimp ponds and the mangrove forests; and ( 4) The uncontrolled expansion of private shrimp farms that place undue pressure on the coastal environmental system. For the management issues relating to the socio-economic setting, these include: (1) The unstable income and lost income; (2) Poor technical knowledge of shrimp farmers; (3) Lack of cooperation among shrimp farmers; (4) Ineffective law enforcement; and (5) Inadequate public awareness program. The recommended framework for resolving the problem include the following management interventions, i.e., (1) Improvement of the effectiveness of the SWI Project; (2) Development of pond management; (3) Development of waste handling practices and the implementation of the waste treatment systems; (4) Usage of mangrove forest for the wetland treatment of shrimp pond waste coupled with mangrove conservation and restoration; (5) Water quality monitoring; (6) Rezoning of shrimp farm area; and (7) Increasing in the level of shrimp farmer's awareness on environmental aspects of shrimp farming. |
| Year | 1997 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Space Technology Application and Research (SR) |
| Chairperson(s) | Apisit Eiumnoh; |
| Examination Committee(s) | Lin, Chang Kwei;Suphat Vongvisessomjai;Sanit Aksornkoae;Routray, Jayant Kumar;Fortes, Miguel D.; |
| Scholarship Donor(s) | Royal Thai Government; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1997 |