Diversified Uses of Abandoned Shrimp Ponds

Home , Fish pond

Md. Zakir Hossain and C. Kwei Lin

ITCZM Monograph No. 5 Series 2001

Gulf of Thailand

A Case Study in the Upper Gulf of Thailand

Extensive shrimp farm

Abandoned Salt farm shrimp ponds ? Mangrove Rehabilitation

1 Diversified Uses of Abandoned Shrimp Ponds

A Case Study in the Upper Gulf of Thailand

Md. Zakir Hossain and C. Kwei Lin

The Integrated Tropical Coastal Zone Management at AIT is an area of specialization under the Schools of Environment, Resources and Development and Civil Engineering. This interdisciplinary field aims to develop human resources for coastal zone management in the Asia and the Pacific regions where the coastal areas encompass a diverse array of resources and ecosystems with intense human activities.

ITCZM MONOGRAPH SERIES

This series contains an extract based on the M.Sc. theses to reach the public.

Md. Zakir Hossain and C. Kwei Lin. 2001. Diversified Uses of Abandoned Shrimp Ponds - A Case Study in the Upper Gulf of Thailand. ITCZM Monograph No. 5, 23 pp.

2 Contents Abandoned Shrimp Ponds - A Disaster in the Coastal Areas 4 What Lies Behind? 4 Why This Study? 6 Study Area - A Profile with Major Land Use Changes 6 Methodology of the Study at a Glance 10 Extent of Severity - A Decade of Changes in Marine Shrimp Farming 10 Environmental Constraints for Further Rehabilitation 11 Rehabilitation or Re-use of Abandoned Shrimp Ponds 12 Environmental and Biotic Characteristics of Land Use Systems 16 Economics of Three Land Use Systems 18 Legislative Administration, Policies and Regulations 20 Recommendations 22 Further Reading 23 Main References 23 Acknowledgements 23

3 Abandoned Shrimp Ponds - A Disaster in the Coastal Areas

The history of shrimp farming in Thailand is production. The accurate estimation of pond about 75 years beginning in the 1920s with abandonment is difficult either in terms of total traditional type of farming mainly in the extent or number of ponds and, with the stocking ponds of salt farms. Large-scale exception of Thailand, there is little intensive shrimp farming began to accelerate quantification of pond abandonment reported in the literature. However, unofficially it can be as high as 70% after a period of shrimp § Large-scale intensive shrimp farming production and in 1996 there were 20,800 ha accelerated in Thailand after 1985. of abandoned shrimp ponds in Thailand with § Rapid expansion occurred during an economic loss of about THB 5,000 million 1986 and 1989 that made Thailand [1]. the world largest shrimp producer since 1995. § Unofficial quantification of pond abandonment says that it can be in Thailand after 1985 with the adoption of an as high as 70% after a period of aquaculture promotion policy and the first area shrimp production. to be intensively developed was the Upper Gulf § In 1996 Thailand saw 20,800 ha region. Particularly rapid expansion occurred of abandoned shrimp ponds with during 1986 and 1989, when the production in an economic loss of about THB the major prawn producing countries was 5,000 million. affected by environmental degradation. Thailand had become the world’s largest shrimp producer by 1995. This rapid What Lies Behind? development of marine shrimp farming was not The main reason behind this crash was smooth and there has been a large-scale improper planning and management, which has resulted, inter alia, in some specific problems, i.e., acidification of soils, shrimp diseases, poor water quality and self-pollution. An abandoned shrimp pond can be defined as a shrimp pond, which Another reason was the introduction of new after a period of production farmers with little knowledge of aqauculture becomes unproductive due to into marine shrimp farming because it was disease and/or environmental highly profitable. degradation, and then loses the farmer’s attention. From many studies it has been found that the declining environmental suitability, weak Abandoned Shrimp Pond institutional arrangement, weak environmental awareness and deliberate policy of the conversion of mangroves and other land uses shrimp farmers were the main causes for the into shrimp ponds. Many of these conversions appearance of abandoned shrimp ponds in have proven non-sustainable with the result Thailand. Abandoned shrimp ponds are the that a large number of ponds have been left ultimate effect of the failure of shrimp abandoned after a period of shrimp production.

4 Some of the direct causes of shrimp pond abandonment in Thailand have been identified as :

• Diseases outbreaks • Environmental degradation and self-pollution • Shrimp farming development through mangrove destruction and consequences like acidification.

Abandoned Shrimp Ponds

Lack of Deliberate No Loss of Political Financial policy of Investment Confidence intervention EFFECTS Support farmers

Shrimp Production Collapse PROBLEM

Degrading Quality Disease Outbreak Poor Farm of the Aquatic Management Environment

Mangrove/ Lack of Co- Insufficient Weak High Using wetland ordination of Shrimp Shrimp Stock same degradation Wastewater/ Health Seed and Density sources Sludge Management Feed of water

Disposal Quality CAUSES

Weak Weak Zoning Weak Shrimp Farmer Weak Institutional Environmental and Organization Linkage Mechanism Awareness Enforcement

Problem Tree of Shrimp Farms Abandonment in Thailand

5 Why This Study?

A few years back most of these abandoned areas were converted back into extensive shrimp farms, salt farms and rehabilitated mangrove. These conversions had an economic impact that put many farms out of business. In 1995 the production from extensive shrimp farms was only 93.75 kg/ha/ crop with an average income 509.17 USD/ha/ crop or 1,018.34 USD/ha/year in comparison to 504.72 USD/ha/year from salt farm. In Remaining part of a farmhouse of an abandoned contrast the income from intensive shrimp shrimp farm farming in 1989 was 5,078.88 USD/ha/crop or consulting with internationally recognized 10,157.76 USD/ha/yr. The mangrove replanting resource persons resulted in the objectives to was an investment with long term direct compare an integrated mollusk-shrimp-fish monetary return. So there was a need to find farm model, that is practiced also in an alternative options with quick and reasonable abandoned shrimp farm in Samut Skahon income for the farmers facing difficulty with Province, with two other common options abandoned shrimp farms. However, (mangrove replanting and salt farming) sometimes rehabilitation or reuse of practiced by the farmers. It was attempted to abandoned shrimp farms becomes difficult compare these three options considering because of the prevailing environmental existing economic and environmental conditions in the ponds. It is also predictable conditions. that until sustainability is achieved in marine shrimp farming, countries will continue to see Study Area - A Profile with the appearance of abandoned and Major Land Use Changes unproductive ponds, and continue to see degradation of the resource base on which the Location coastal communities, particularly the local poor depend. Samut Sakhon Province, located at Latitude 13o12’N-13o40’N and Longitude 100o20’E- Therefore a reconnaissance survey and 100o30’E, is one of the Upper Gulf Provinces of Thailand where rapid development of intensive shrimp farming started soon after Since the abandonment of shrimp ponds appeared, the coastal zone 1985 and that saw a huge number of management issue of what to do and abandoned shrimp ponds after just 5 years. how to deal with the extensive Samut Sakhon is 28 km from Bangkok and has abandoned lands became a major an area of 872 km2. challenge for the country. Until 1995 the existence of abandoned shrimp ponds Samut Sakhon, formerly called Muang Tha was largely denied but just one year later the rehabilitation and management Chin and later Muang Maha Chai after digging of abandoned shrimp ponds was the Mahachai canal, received its present name identified as a “priority research” area. of “Samut Sakhon” during the reign of King

6 Rama IV. However, it is still called Mahachai by the locals and villagers. Samut Sakhon Province is administratively divided into three Gulf of districts (Muang Samut Sakhon, Krathum Thailand Baen, and Ban Phaeo). The main river flowing through this province is Tha Chin, which is a branch of the Chao Phraya, 325 km long and meets with the Gulf of Thailand at Maha Chai town.

The location of the study area

Coastal Environment, Oceanography and Climatic Conditions one high tide per day. The data from Royal Thai NAVI shows that the tidal range near the Tha Samut Sakhon is generally a low elevation of Chin river mouth varies from 0.9 m to 3.19 m coastal plain with the Tha Chin River running above the lowest low water level. The from north to south. In addition there are a average high tide near Tamboon Maha Chai is number of natural and man made canals throughout the province. The southern part of the province is primarily low-lying land parallel § The province has a 42-km long coastline. to the coastal area and used for salt making § Tidal range varies from 0.9 m to 3.19 m. § Average temperature is 21-36oC. and shrimp farming. The province has § The relative humidity varies from 63-80%. approximately 42 km of coastline. The coastal § The average yearly rainfall is 1400mm. bed is a muddy flat with a slope of about 1%. § Three seasons: summer from February to The tidal period is mixed between a semidiurnal April, a rainy season from May to October and a diurnal tide producing two low tides and and winter from November to January.

7 40 350

35 300 30 250 25 C

o 200 20 15 150 Rainfall (mm) 10 100 5 50 20 21 22 4 9 12 8 0 2 0 2 1 2 0 Jul Apr Oct Jan Jun Feb Mar Aug Sep Nov Dec May

Extreme Max Extreme Min Total Rainfall (mm) Rainfall Days

Monthly maximum and minimum temperature Average monthly rainfall with rainfall days

1.11m, whereas the low tide reaches –0.36 m to 3.70 km/hr. The inshore wind ranges from from the mean sea level. The current flows 8.88 km/hr to 82.5 km/hr creating surface northwards during high tide and southwards waves ranges from 0.22 to 2.10 m in height. during low tide at a flow rate ranging from 2.70

Timeline of Major Land Use Changes

1925 ‘30 ‘35 ‘40 ‘45 ‘50 ‘55 ‘60 ‘65 ‘70 ‘75 ‘80 ‘85 ‘90 ‘95 2000

Mangroves Shrimp farming with stocking and salt started. Rest ponds of salt farms Shrimp marshes first and mangroves converted into farming converted into shrimp ponds. collapsed salt farm and People traditional leave the shrimp pond. Rapid expansion of intensive shrimp area and hundreds farming. All mangroves eventually Linda Storm, 1997 converted into shrimp ponds of shrimp ponds become one Intensive shrimp farming faced dramatic declining aband d and mangrove area entirely encroached.

Mangrove rehabilitation started. Abandoned shrimp ponds converted back into salt farms, extensive shrimp farming and integrated aquaculture farm.

Timeline of land use changes in the study area (1925-2000).

8 Changes in Mangrove Forest and Shrimp Farming Area

Mangrove forest distribution data are available Council Office) and RFD (Royal Forestry for the entire country since 1961 and for Samut Department) clearly show that the mangrove Sakhon Province since 1975. The data forest cover in Thailand has continuously interpreted from aerial photos in 1961 and later decreased. In 1961 the mangrove forest on from Satellite Images (Landsat-1 to covered some 368,000 ha of the entire Landsat-5) by NRCO (National Research country while, as in 1996 it was 168,000 ha.

20000 18500 400000 18000 350000 16000 14416 300000 14000 12000 250000 Sakhon (ha) 10000 200000

8000 150000 Country's total (ha) Samut 6000 100000 4000 1819 1696 2000 50000 142 0 0 0 0 1961 1975 1979 1986 1989 1991 1993 1996 Year

Samut Sakhon Country's total

Changes in mangrove forest cover in Samut Sakhon Province and Thailand

In the last 35 years 200,000 ha (54%) of Province had virtually lost its entire mangrove mangrove forest cover have been destroyed at forest from 18,500ha in 1975. At this time the an average rate of 5,723 ha per year. The data shrimp farming area also had been increased also show that in 1989 Samut Sakhon to its highest level of 12,259.52 ha [2].

80.00 70.00 60.00 50.00 40.00 30.00

20.00 12.26 9.72 8.01 8.19 7.62 7.61 7.40 7.22 7.19 6.27

Area ('000 ha) 10.00 - 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 Year

Thailand Samut Sakhon

Changes in shrimp farming area in Samut Sakhon Province and Thailand

9 Methodology of the Study at a Glance

Data Collection Data Analysis

· Direct PRA and RRA observation § National and Local Policy and · Interview of Descriptive Plan key persons Statistics § Erosion and Environmental Disaster parameters PRIMER - Water Quality Multivariate - Sediment Analysis Parameters Results and Cost-Benefit Recommendations Biotic factors Analysis - Meiofauna

Economics SWOT analysis

Extent of Severity: A Decade of Change in Marine Shrimp Farming

The traditional shrimp farming in Samut Sakhon 14,000 12,134 Province started more than 75 years ago. With 12,000 a sudden fall in salt prices in 1947 the number 10,000 8,156 of farms started to increase, until it reached 8,000 6,273 1,102 farms in 1985. Until 1985 the farms were 6,000 classified into “With Stocking” and “Without 4,000 2,269 1,102 1,048 Stocking” distributed as 37 farms with an area 2,000 0 of 21.6ha and 1,065 farms with an area of 7,940 1985 1989 1995 ha respectively. The number of shrimp farms steadily increased after 1985 and reached No. of Farms Area (ha) 2,269 farms (11.9% of country’s total shrimp farms) in 1989 with an area of 12,134.24 ha TheThe changeschanges ofin shrimpshrimp farmsfarms (1985-1995) (1985-95) (16.1% of country’s total shrimp farming area). The provincial shrimp farming area was were 413 farms (3,305.92 ha) with extensive 8,156.48 ha in 1985, which had been raised farming, 584 farms (2,963.36 ha) with semi- 48.77% in 1989. This had happened with the intensive farming and 1,272 farms (5,864.96 establishment of new farms and the ha) with intensive farming. Within four years development of old farming areas. In 1989 there (1985-1989) the number of shrimp farms

10 increased 105.90% in Samut Sakhon 5,651 Province. After 1990 the number of 6000 5000 shrimp farms began to decrease steadily 4000 2,739 with environmental problems and the 3000 spread of diseases. A report, published 2000 1120 on the state of the environment of 1000 544 Thailand [2], says that around 40,000 ha 0 of shrimp farming area in the Upper Gulf Semi-intensive Intensive of Thailand became abandoned, which 1995 forced 90% of the farmers out of No. of farms Area (ha) business. In this connection 53.81% of the shrimp farms stopped their activities Number of abandoned shrimp farms with area in 1995. in Samut Sakhon Province in 1995, which Number and area of abandoned shrimp farms had accounted for 48.30% of the total in 1995 shrimp farming area in 1989. Whereas · About 73% of the shrimp farms the number of extensive shrimp farms and 60% of the shrimp farming during this time increased dramatically area became abandoned during from 413 farms in 1989 to 856 farms in 1989 to 1995. 1995. · The estimation shows that a total of 1,664 shrimp farms had been abandoned in 1995 with an area Environmental Constraints of 8,390.24 ha. for Further Rehabilitation The environmental conditions remaining after a result the environmental conditions that once abandonment may be more important than the fostered the growth of mangrove forest might causes of failure. They may be unrelated. For have been removed or severely altered, which instance, in Karnataka, India many hundred can cause complications for the rehabilitation ponds had been abandoned as a result of white of those abandoned areas. The likelihood of spot disease but the major obstacle to the re- mangrove rehabilitation might be severely development of these ponds was not the limited by the reduction in the soil quality presence of disease, but the remediation of through increased erosion, activation of acid acid sulphate soils which may persist for many sulphate soil and addition of chemicals. years after abandonment [3]. The remediation of acid sulphate soils of In addition the effects of mangrove clearance abandoned shrimp ponds is time as well as and consequent abandonment may cost intensive. Continuous flushing with fresh accelerate soil erosion due to increased or brackish water can enhance the oxidation surface runoff and subsurface flow, decrease of acid producing materials and washing out in soil water storage capacity, reduction in soil of the acids. The number of flushings, as high fauna biodiversity and transport of sediments. as 150, may be reduced by drying and tilling It may also accelerate the dissolution of the ponds in between flushing. However this inorganic and organic constituents and principal flushing method would not be advisable if the nutrients and the depletion of soil organic area shows poor tidal flushing and has an matter through leaching and mineralisation. As ecological problem of acid leachate [3].

11 Rehabilitation or Reuse of Province, Thailand. After assessing the growth Abandoned Shrimp Ponds it was recommended that the abandoned shrimp ponds similar to the study site in na- Rehabilitation Options ture can be rehabilitated with the species Rhizophora mucronata, Rhizophora apiculata, The causes of failure of shrimp farming and Bruguiera cylindrica as those species grow the resulting conditions in the abandoned well and lead quickly to the recovery of the shrimp ponds are the most important concerns mangrove ecosystems [4]. The use of three that must be taken into account for the species was also recommended because it rehabilitation or reuse of abandoned ponds. The mimics the structural complexity of natural most common problems that might occur in multi-species forest with only slightly slower abandoned shrimp ponds are hard substrate growth rate. unsuitable for other agriculture activities, acidification of soil and water and high organic Among the other possibilities and suggestions load. However, despite these potential aquasilviculture might have a significant obstacles there are also examples of reuse of potential. In the Philippines particularly the abandoned shrimp farms, some of which may abandoned shrimp ponds that have been left be regarded as successful. But it is important due to acid sulphate soil are suggested as to examine sustainable conversions and being suitable for the development of identification of ‘best use’ scenarios for aquasilviculture, which promotes a abandoned ponds. harmonious co-existence between fishery species and mangrove tree species while also The information regarding rehabilitation of providing coastal protection and maintenance abandoned shrimp farms are not rich at all. The of the ecosystem. only information available is about mangrove replantation in an abandoned shrimp farm in Existing Reuses of Abandoned Shrimp Thailand. All others are possibilities and Farming Area suggestions. In 1992 a replantation was done in an abandoned shirmp pond at Ranong In Samut Sakhon Province a total of 8,390.24 ha area has been abandoned from shrimp The possibilities for rehabilitation of farming during 1989 to 1995. Very soon most abandoned shrimp ponds include (present of the farms were converted into extensive study and [3]): shrimp farms. Since the Government had a policy of mangrove rehabilitation, many farms Extensive shrimp farming · along the seashore and river were replanted · Fish farming (Seabass farming, Crab culture, Grouper farming) with mangrove trees. The extensive shrimp · Integrated aquaculture farming area in Samut Sakhon Province was · Aquasilviculture increased from 3,305.92 ha in 1989 to 5,835.2 · Mangrove plantation ha in 1995. The provincial salt farming area · Salt production and Artemia culture changed from 1,312 ha in 1992 to 5,546.24 ha · Polychaete culture in 1994 [1]. The rehabilitated mangrove area · Coconut plantation also increased from 0 ha in 1989 to 1,819.04ha · Industry and housing development in 1993 [2]. Most of these conversions § Top soil sale happened from the abandoned shrimp farms.

12 PreparationPreparation of of salt salt pans pans or or crystallizer crystallizer HarvestingHarvesting ofof salt salt A survey in Moo Hok, Tamboon Bang Ya Phreak, extensive aquaculture (shrimp, shrimp and Muang Samut Sakhon shows that 30% of the fish, shrimp and mussels) and reservoir of salt abandoned shrimp farms were replanted by farms. In Bang Ya Phraek sub-district, there mangrove and 30% were converted into salt were no salt farms in 1992. However, in 1994, farms. The remaining 40% have been used for there were salt farms existing which covered 463.04 ha. The area covered by mangroves increased from 50.08 ha in1992 to 110.08 ha in 1994 (Anon, 1995b and current survey). However, data may be inaccurate as the statistics is only Mangrove replantation in available from abandoned shrimp pond productive farms. and the mangrove area in Samut Sakhon province

Extensive 10,000 shrimp farm 8,000 6,000 4,000 2,000 Abandoned Salt farm 0 shrimp Extensive Salt farm Mangrove ponds shrimp pond replanting

Rehabilitated 1989-90 (ha) 1996 (ha) mangrove

Conversion of abandoned shrimp farming area into three main land use systems.

13 Development of an Integrated Mollusk- Shrimp-Fish Farm in Abandoned Shrimp Culture species in different ponds There are six important species for this nature Ponds dependent farm, which are also commercially feasible in the local as well as in the international Around 1975, the farm “Wang Koong market (especially the two shrimp species). Maneerat” had been established as an Besides the six main commercial species there are several shrimp, fish and mollusk species extensive shrimp farm (Stage 1) by digging out which can also be found as a bycatch. The 5 ponds in a total area of 38.4ha (240 rai). The important species are: input was only the high tidal water; there was no application of feed or seed from outside. · Fish - Seabass (Lates calcarifer) The production was not so good. So the - Mullet (Liza valamugil) system lasted only a few years. After a few · Shrimp years the owner had converted his five ponds - Banana Shrimp (Penaeus merguiensis) into one pond (Stage 2) by digging out the dyke - Tiger Shrimp (Penaeus monodon) · Mollusk soil. It was an improved extensive type of - Green Mussel (Perna viridis) shrimp farm with feed application but also - Blood Cockle (Anadara granosa) lasted only a few years due to poor production and benefits. Around 1985, when intensive especially in the Upper Gulf Provinces, the farm shrimp farming was booming in Thailand owner had changed his farm into intensive shrimp farm and dug out 10 ponds (Stage 3), each of which had a water body of 10 rai (1.6 ha). The shrimp species Penaeus merguiensis was being farmed in one pond and the other 9 ponds were for Penaeus monodon. Around 1995 because of the disease, environmental degradation

Gulf of Thailand and low price, which had worked synergistically, the Sea wall

Integrated Farm

Scale: 430 m

Integrated mollusk-shrimp-fishIntegrated mollusk-shrimp-fish farm farm

14 farm became abandoned. Two years later the this pond also has fish and low density of farm owner dug out all the dykes and made 3 shrimps. Shrimp culture is practiced in the pond different sizes of ponds and developed the no. 1 in an extensive way of farming. This pond present integrated system (Present stage or has an area of 24 ha, which has also been stage 4). used as a trap pond for all the farmed species and a culture bed of blood cockle. Ponds 3 and Today in the 4th stage system pond no. 2, which 4 have the same area of 1.6 ha each, where has an area of 6.8 ha is being used for green mainly fish and low densities of shrimps are mussel farming with raft culture system. But raised.

Important Mananagement Aspects and Issues of Three Land Use Systems

Systems Integrated Mangrove replanting Salt farming mollusk-shrimp- fish farm § Water quality § Sediment trapping § Season and water § Pond preparation before § Preparation of management plantation stocking ponds and Management § Stocking § Seedlings (nursery pans aspects § Feed input produced potted seedlings § Stocking of § Harvesting had better survival). seawater § Plantation time § Complex technical § Protection method of salt precipitation § Erosion and § People’s perception and § Seasonality and low farm protection interest production § Industrial § Periodic erosion and § Price fluctuation Issues pollution and accretion § Quality and pesticides § Barnacle infestation Government policy § Likelihood of § Sesarmid crab (Sesarma § Marketing of brine frequent storm taeniolatum) § Poaching § Sometimes monkeys

Erosion of mangrove and shrimp farm (left), stocking pond for selling of high salinity water (right)

15 Environmental and Biotic NH3-N (St. not more than 0.4 mg/L) Characteristics of 0.50 Three Land Use Systems 0.40 Water and Sediment Quality 0.30

mg/l 0.20 The environmental condition of the integrated mollusk-shrimp-fish farm is similar to the 0.10 replanted mangrove in terms of water quality 0.00 parameters, soil texture and organic matter of Int. Aq. Farm Mangrove Salt sediment. Whereas the environmental condition of the salt farm is entirely different Jan Feb Mar Apr Standard from the integrated mollusk-shrimp-fish farm and replanted mangrove in terms of water below 0.7 mg/l, many aquatic organisms along quality (temperature, salinity, pH, NH -N and 3 with most important commercial species of inorganic phosphate) and sediment shrimps would normally die. The study shows parameters (soil texture and organic matter). that the DO is slightly lower but NH -N and PO - This is naturally expected due to 3 4 P are slightly higher than natural conditions. characteristics of the salt production process that results in an extreme saline environment. High ammonia concentrations decrease the growth rate of many aquatic organisms. DO (St. > 4 mg/L) Usually it affects the oxygen transportation capacity of blood. Phosphorus is an important 5.00 plant nutrient for the growth of phytoplankton. 4.00 The form of phosphorous that phytoplankton 3.00 is able to utilize is inorganic orthophosphate,

mg/l 2.00 which has a solubility of less than 0.1 mg/L in 1.00 saline water. Orthophosphate is usually 0.00 precipitated and absorbed between the clay Int. Aq. Farm Mangrove Salt particles at acidic pH and reacts with calcium at basic pH.

Jan Feb Mar Apr Standard PO4-P (St. Natural Condition) The environmental study also shows that the 0.40 temperature, pH and salinity of integrated 0.30 mollusk-shrimp-fish farming are same as with planted Avicennia and Rhizophora forest and 0.20 below the accepted limit of standard coastal mg/l 0.10 water quality set by the Pollution Control Department (PCD) of Thailand. Dissolved 0.00 oxygen is important in supporting life of aquatic Int. Aq. Farm Mangrove Salt fauna and for the bacterial degradation of organic matter. If the DO level is reduced Jan Feb Mar Apr PCD meas.

16 The soil texture of the integrated mollusk- shrimp-fish farm and mangrove is silty-clay- Meiofauna can generally be defined as loam, whereas it is silty clay in the salt farm. animals that pass through a 0.5-mm mesh One of the major problems of abandoned sieve but are retained on a 63-mm mesh shrimp farms regarding their rehabilitation is sieve. They are the dominant metazoans in most coastal and estuarine habitats [5]. the soil quality which becomes hard, highly Nematodes and copepods constitute over acidic and with low organic matter. 90% of the hard-bodied components of this fauna and play an important role in Meiofaunal Importance, Abundance and decomposition process. They also form the Diversity in Three Land Use Systems prey for commercially important fish and shrimp species and serve as food for higher trophic levels. Meiofauna are known to be We identified 14 meiofaunal taxa (including one sensitive indicators of environmental undetermined) from 3 different groups of perturbations because of their large stations (13 in integrated mollusk-shrimp-fish numbers, relatively stationary life habits, pond, 9 in the shrimp pond replanted with short generation times, benthic larvae and intimate association with sediments known mangrove, 8 in the pond of a salt farm) and 36 to accumulate various contaminants. samples (12 from each station). The most abundant taxa were the nematodes for the integrated mollusk-shrimp-fish pond and the specimens in most of the samples). shrimp pond replanted with mangrove followed Sarcomastigophora was the most abundant by copepod in the pond of a salt farm. In the taxon after nematodes in the shrimp pond integrated mollusk-shrimp-fish pond other replanted with mangrove, whereas in the pond abundant taxa were copepods, polychaetes, of a salt farm ostracoda and bivalve mollusks sarcomastigophora and tunicata (tens of were most abundant after copepods.

Water quality parameters of three land use systems showing means and standard deviations.

Sediment characteristics of integrated mollusk-shrimp-fish farm, replanted mangrove and

17 The pairwise test of One-way ANOSIM (PRIMER-multivariate tool) shows that the § The abundance of meiofaunal taxa in abundance of meiofaunal taxa in three systems each system was significantly were significantly different (P=<0.05%) from different from one another. one another and the difference in abundance § between 3 sampling occasions within each The diversity of abundance of station were not significant. The SIMPER test different taxa in integrated mollusk- shows that the dissimilarity percentages of shrimp-fish farm was higher than in meiofaunal abundance in integrated mollusk- the other two systems. shrimp-fish farm versus mangrove and salt § The most significant parameters are farm are 30.20% and 39.79% respectively. ammonia nitrogen and organic Whereas the dissimilarity percentage of mangrove versus salt farm is 28.98%. The cumulative abundance of the first three taxa is The average dissimilarity of meiofaunal taxa in 3 36.64% for integrated mollusk-shrimp-fish stations in 3 sampling occasions farm, whereas for mangrove it is 50.09% and Station groups Dissimilarity % for salt farm 56.44%. This means that the 14 identified taxa in integrated mollusk-shrimp-fish St.M, St.A 30.20% farm were more highly diversified than the 9 St.S, St.A 39.79% identified taxa for mangrove and 8 taxa for salt St.S, St.M 28.98% farm. Finally BIOENV result shows that the St.A = Integrated mollusk-shrimp-fish farm, St.M = Mangrove, St.S = Salt farm most significant parameters are NH3-N and organic carbon. Results of SIMPER test showing the similarity of all the taxa identified from 3 stations Stations Average First 3 taxa and their cumulative abundance in each station similarity Taxa Cumulative abundance of 3 taxa Integrated mollusk- 90.49% Nematode, Copepods and 36.64% shrimp-fish farm Polychaetes Mangrove rehabilitation 89.85% Nematode, Sarcomastigophora 50.09% and Ostracoda Salt farm 87.29% Copepods, Ostracoda and 56.44% Bivalve mollusks Sample size = 12 Economics of Three Land Use Systems Cost-Benefit and Economic Return people’s interest and perception. This is For the economic study of the integrated because the local people care about the wood mollusk-shrimp-fish farm, mangrove and salt resources rather than other benefits of farm a cost-benefit analysis of each system mangroves. has been done. The economic valuation of mangrove can be done in many ways using The economic study shows that the financial different benefits from mangrove. However for return of the integrated mollusk-shrimp-fish this study only the potential wood resources farm per year varies from USD 1,877.55 to USD are taken into consideration due to the local 3,341.44 per hectare, whereas the returns from

18 the salt farm varies from USD 500.63 to USD the range of USD 3207.73 to USD 4,090.45 1,733.97 per hectare per year. The economic per year. Here the word productive is used return of mangrove only from wood resources because a planted forest can become a varies from 4,689.67 USD to USD 14,519.22 productive forest after 15 years of plantation per hectare that can be achieved after 12 years. (Sathirathai, 1998). The case study has Here the economic return from the mangrove considered direct use value, offshore has been calculated using the discounted value fisheries linkage and coastline protection of potential wood resources at 6% discount using selling of locally exploited products, rate as the benefit can be achieved after 12 surrogate prices of subsistence products and years. But considering only the wood cost to build a seawall. Here the high economic resources is not the exact valuation of return from the mangrove obviously comes mangrove as it has several other benefits. In from the over estimation in terms of coastline this connection the results of a case study has protection (2,991.35 USD/ha). been used to compare all other benefits that can be achieved from one ha of mangrove. Economic Potential of Sensitive Relation According to this case study the economic of the Three Land Use Systems return from 1 ha of productive mangrove is in The economic study shows that the cost benefit ratio of the integrated mollusk-shrimp-fish farm 3,500 and salt farm are in the range of 0.38 to 0.21 3,000 3,000 and 0.66 to 0.19 respectively. The cost benefit 2,500 ratio of mangrove is higher than the above- 2,000 mentioned two systems, namely are in the 1,500 1,000 range of 0.21 to 0.07. 1,000 592 500 0 From this study it has been found that all those Integrated Mangrove Salt three systems have some sensitive relation mollusk- replanting farming with the environment in terms of viability and shrimp-fish profitability. The most sensitive venture among farm these three systems is salt farming because Investment USD/ha

4,000 3,341 3,500 3,000 Main Products from 1 ha of three different 2,500 2,000 1,734 resources uses systems 1,210 1,500 1,000 714 Systems Products Amount/ha 1,000 333 500 Integrated Shrimp 0.094 – 0.375 MT 0 Aquaculture Fish 0.615 - 0.633 MT Integrated Mangrove Salt farming Farm Mussel 2.604 - 3.125 MT mollusk- replanting Cockle 1.953 - 2.604 MT shrimp-fish Mangrove Wood for 1700 – 2000 plants farm Plantation charcoal (21.25 – 39.00 m3) Salt Farm Salt 40 – 48 MT Cost (USD/ha) Benefit (USD/ha)

Investment, products and cost-benefit of three different systems

19 of its dependence on season, government Legislative Administration, policy and price fluctuation. In years with longer wet season or higher total rainfall production Policies and Regulations for the can be decreased more than 30%. The average Utilization of Coastal Lands in yearly production and income per hectare Thailand decreased from 40-48 MT with a benefit USD 500.63-1,733.97 to 26.67-32.00 MT with a The Thai government agencies responsible for benefit USD 222.86-1,045.08. But the worst coastal area administration and coastal thing that can happen is if the price per MT resource management can be grouped in three decreases from USD 20.83-43.06 to USD 6.94. categories (Jenkins et al., 1999 and Anon, In this case the yearly benefit may decrease 1995): Policy agencies, planning agencies and from USD 500.63-1,733.97 per hectare for the implementing agencies. Besides many average farm production to USD 0.34-(-78.67) agencies there are also some national for the wet season case. committees and provincial sub-committees that develop policies and give advice to the The sustainability of mangroves is mostly planning and implementing agencies (Figure dependent on the erosion problems that the 17). As many agencies, as authorized by laws, area is facing. If there is no severe erosion in have been working in the coastal areas the area the mangrove area will be sustained, without proper coordination, the duplication of as the plantation seems to be successful. But work and conflicts have occurred owing to the if part of the planted area erodes the profit that job description by laws (Anon, 1995). Even has been computed from the wood resources though several committees have been will not be obtained along with the other benefits established to resolve these problems, they for mangroves. have not been successful, as those committees had no authority to control the The integrated mollusk-shrimp-fish farm is activities of other agencies. more sensitive to pollution than to other problems facing the salt farm and mangrove Besides, the Department of Fisheries (DOF) plantation. One of the major concerns has a strong policy of relocating the shrimp regarding pollution of this farm is that it is farms that have been sited inside the coastal situated near the Maha Chai industrial estate mangrove fringe, facing abandonment and near the mouth of Tha Chin River. problems and running with low production. According to the farm owner the shrimp and Other important policies regarding shrimp fish harvest decreases because of the polluted farming are the conversion of extensive and water. He has observed many times like semi-intensive farms into intensive farms, October 2000 when the dead fish, shrimp and registration of shrimp farms, enforcement of other aquatic fauna were floating on the water effluent treatment before discharging into the surface. The highest shrimp production he can recipient waters and implementation of get is 0.094-0.375 MT per hectare with an seawater irrigation systems. income of USD 362.50-1,450.00 but due to pollution the production can be stopped at In 1987, using satellite technology as a base 0.094-0.11 MT per hectare with the income of line information, the Royal Forestry USD 362.50-428.13. The farm owner also Department (RFD) had done a land use blamed pollution for hindering the growth of the zoning of mangrove areas in three principal green mussels as his daughter is facing this zones: problem. 20 · Conservation Zone Policy Formulation and Co-ordination Agencies (427sq.kilometers): mangrove forests in § Office of national Economic and social Development Board (NESDB) this zone are strongly § Office of Environmental Policy and Planning (OEPP) protected from any impacts on natural § National Environmental Board (NEB). environmental values. § Land Development Committee. No exploitative uses § Central Sub-committee on the Development of Coastal Areas. are permitted. § Provincial Sub-committee on Coastal Area Classification and Development. § National Mangrove Resources Committee. · Economic zone A § Provincial Committee on the Classification of Area for Shrimp Culture. (1,997 sq. kilometers): This zone can be used for the exploitation of forest products, e.g. charcoal Planning Agencies production and local uses, on a sustainable § Tourism Authority of Thailand yield basis. § Town and Country Planning Department § National Resources and Environmental Office · Economic zone B § Office of the National Research Council of Thailand. (1,300 sq. kilometers): § Department of Land Development This zone can be used § Office of Environmental Policy and Planning for other activities besides forest product exploitation, with consideration given to the the impacts to the Implementing Agencies environment. § Department of Fisheries (DOF), Ministry of Agriculture and Cooperatives. The Department of Land § Royal Forestry Department (RFD) Development under the § Office of Agriculture Economics direction of the National § Department of Land Development Committee on Land § Pollution Control Department (PCD) § Department of Local Administration, Ministry of the Interior Development, which was § Harbours Department and Department of Highways, Ministry of Transport created by the Land and Communication. Development Act-1983, § Royal Irrigation Department, Ministry of Agriculture and Cooperatives. has an integrated development project for the efficient use of The heirarchy of Thai government agencies responsible for the coastal land, taking into formulation and implementation of policy and planning on utilization of consideration the impact coastal areas on ecological balance.

21 Recommendations Since the rehabilitation of abandoned shrimp after other alternatives (including crab fattening ponds was identified as a priority research area and aquasilviculture) subject to local people’s in late 1996, most of the research has been perception and needs. In addition one dry carried out on mangrove rehabilitation. season salt production and wet season culture However, certain innovations are necessary to of shrimp or fish or both can be an attractive ensure an even better utilization of abandoned option for the salt farmers, as the season for shrimp ponds, aiming at the provision of salt production is short due to the rainy season. sustainable coastal resource utilization and management and creation of sound natural • The further rehabilitation of abandoned environment. Based on the results from shrimp ponds into intensive shrimp farms detailed environmental and economic analysis must be within a closed system framework. In with special reference to integrated mollusk- closed systems, recycling of water using shrimp-fish farming, mangrove replanting and integrated farming of green mussels, blood salt farming, the recommendations have been cockle, seabass and mullet as a bio-filter identified for the rehabilitation of abandoned should be taken into consideration. shrimp ponds in the Upper Gulf coast of Thailand. With some spatial analysis and • Considering mangrove zoning of RFD, modification these recommendations can also the Department of Fisheries (DOF) should also be applied to other coastal areas in Thailand develop aquaculture zoning with specific and other countries facing abandonment of regulations for further development of coastal shrimp farming area. aquaculture.

• Clear identification and marking of three • Strict regulations or ban on the mangrove zones (conservation zone, introduction of outsiders in shrimp farming and economic zone A and economic zone B), which the provision of polluter pays principle should is the prerequisite for the further development be introduced. of the coastal zone, should immediately be carried out by the Royal Forestry Department • An Integrated Coastal Zone (RFD) and demonstrated to the local people, Management (ICZM) framework and working before further development of the coastal zone. body is recommended to develop from the national level to the provincial level. Only the • The integrated mollusk-shrimp-fish primary stakeholders (locals and the most farm is recommended as having the greatest involved government agencies and commercial potential for the use of abandoned departments) should be involved with policy, shrimp ponds subject to RFD’s mangrove planning and implementation of coastal zoning. resources utilization following a top down and bottom up approach. The expected outcome • Abandoned shrimp ponds in the would be the integrated coastal resources conservation zone should be rehabilitated with management policy and plan that ensures the mangrove. sustainable utilization of coastal resources upon which the local poor depend. • Conversion of abandoned shrimp ponds into salt farm should be the last option

22 Further Reading Acknowledgements

Hossain, M. Z. 2001. Diversified Resource This monograph, and the thesis research Uses of Abandoned Shrimp Ponds: A Case project where it was extracted from, were Study in the Upper Gulf of Thailand. AIT Masters published and conducted, respectively, under Thesis, Asian Institute of Technology, Bangkok, DANIDA sponsorship. The research was Thailand. carried out by the first author in partial fulfillment of the requirement for the degree of Master of Main References Science at the Asian Institute of Technology. The second author, the innovator of the ITCZM [1] Anon, 1995. The Environmental monograph series, served as the research Management of Coastal Aquaculture – advisor. Both authors would like to A Study of Shrimp Culture in Samut acknowledge DANIDA for its financial support Sakhon and Chantaburi Provinces, without which this work would not have been NACA (Network of Aquaculture Centers possible. in Asia-Pacific) final report submitted to the Office of Environmental Policy The authors would like to extend their heartfelt and Planning, 1995. thanks to Drs. John A. Rubin, Kathe R. Jensen and Amararatne Yakupitiyage for their great [2] Kaosa-ard, M. and Wijukprasert, P., 2000. support and indispensable suggestions during The State of Environment in Thailand: the research period. A Decade of Change. Natural Resources and Environmental The authors also express their sincere gratitude Program, Thailand Development to Mads Korn and Dr. Kathe Jensen for their Research Institute. August 2000. guidance, close supervision and constructive suggestions throughout this monograph [3] Stevenson, N.J., 1997. Disused Shrimp preparation, and to Arlene N. Satapornvanit for Ponds: Options for Redevelopment of her assistance with the format and layout. Mangrove. Coastal management 25: 423-425.

[4] Muangsong, P., 1998. Reforestation on an Abandoned Shrimp Farm at Hat Sai Khao, Ranong Province, Thailand. In: Coastal Environmental Improvement in Mangrove/Wetland Ecosystems, TCE- Project Workshop No. II. Ranong, Thailand, 1998.

[5] Somerfield. P.J., Gee, J.M. and Arythaka, C., 1998. Meiofaunal Community in a Malyasian Mangrove Forest. Journal of Marine Biological Association. United Integrated mollusk-shrimp-fish farm model Kingdom. 78, 717-732. developed in abandoned shrimp pond in Samut Sakhon Province, Thailand