Plan for Fish Production in

Ponds at Mount Hope

Plan for Fish Production in Ponds at Mount Hope

Introduction

Four small, concrete-walled tanks were built at Mount Hope in 2007 to grow fish as part of the Centre’s vision for self-sufficiency. Two larger fish ponds with earthen dykes were refurbished at the same time. Water was supplied to the tanks and ponds from a spring in the nearby hill. The ponds were stocked with ikan Nila fingerlings (Indonesian for Tilapia nilotica) from a fish farm and hatchery in Pontianak (A. Siregar, pers. comm.). The fish did not grow well, and the ponds dried-up in the extreme dry of the dry-season of 2008, after which fish farming was abandoned. I was asked to review the likely causes of the failure of the fish to grow and thrive and how to revive fish farming at Mount Hope.

Figure 1. The four fish tanks at Mount Hope Training Centre. They are 0.3, 0.06, 0.07, 0.10 ha in size.

I reviewed the published information on Tilapia, talked to as many people as possible who had observed the events and looked at the situation on the ground. I concluded that the Tilapia supplied were unmodified stock and in the mixed sex population, precocious maturation, frequent spawning and extended parental care had led to overpopulation and stunting. As the spring water supply dried up and the water in the tanks shrank, the poor water quality developing would have reduced growth further and increased disease mortality.

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I propose to revive fish farming at Mount Hope by developing a good supply of high quality water from a bore; to adapt pond structure so good aquaculture practices (GAP) can be instigated; and to start growing a fish that is highly adapted to local monsoon conditions and is more productive, more able to thrive in low quality water than Tilapia, and not able to breed under culture.

This plan envisages re-developing the fish farm: constructing drains so each tank can be emptied. Good Aquaculture Practice (GAP) and disease prevention require 1. sludge on tank floor be removed after the grow-out cycle; 2. for the tank floor to be able to dry out in the sun to help sterilize it and allow gaseous ammonia evaporate; 3. for the tank floor to be treated with organic insecticide; 4. for the tank floor to be top-dressed with lime to raise pH to neutral; 5. for bottom topography to be smoothed to facilitate catching of fish by seining; 6. to increase water volume in each tank if possible (by deepening, or raising dykes) to buffer changes in water quality; 7. by replacing the less-reliable spring-water supply with a good supply of high quality water from a bore; 8. by purchasing two large generators to ensure continuity of electricity supply so no part of the farming operation is put at risk, 9. to grow the Striped Mekong Catfish, Pangasianodon hypophthalmus in place of the less productive (x2), and less robust (requiring much higher water quality) Tilapia; 10. to develop a sustainable aquaculture system using effluent water to grow vegetables aquaponically in a floating raft system.

Figure 2. Pangasianodon hypophthalmus at fish market Miri, Sarawak, still alive and breathing air.

Steps to achieve this

1. Secure water supply. Replace unreliable spring with good supply from bore, getting sufficient water for farming and domestic water for the Centre into the future.

2. Sunggau hydrographers survey Mt. Hope site; determine where to drill and how deep (survey cost around $4000?).

3. Bore drilling. Frank Ho suggested getting Malaysian driller? Can we get him and his gear across the border? Is there a Pontianak contractor? (c$30 000? Could be greatly increased if bore needs greater depth to reach aquifer).

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4. Secure electricity supply for aeration, for pumping water, for pumping sludge, running ancillary gear (at least 2 big diesel generators, c$40 000p with the capacity to supply the fully developed site-including hospital?)

5. Methods of growing catfish today emphasize Good Aquacultural Practice that have standards that can be certified (eg EurepGAP, GlobalGAP, ASC, (Hilbrands, 2010; World Wildlife Fund, 2010)). GAP practises include being able to partially drain ponds to harvest, completely drain ponds to empty sludge, to let dry out and lime to protect against disease. Drainage systems will need development to achieve this.

6. Grow-out cycles of crop need to be staggered between 4 ponds so that the flow of fish effluent of similar enrichment is available for aquaponics. Maintaining continuous steady vegetable growth under fish effluent aquaponics requires some juggling of production. Little water exchange in ponds in early growth cycle, 30-50% day-1 later on? More water exchange gives better quality of fish and lower disease. Staggering growing cycles also gives more reasonable spread of harvesting. Daily water need could be up to 1057 m-3 day-1 or 1.057 million litres day-1 (based on 100% water exchange).

7. Aquaponics raceway for raft aquaponics (cover over top like present vegetable gardens) to shade a little, but more to exclude water effect of rain diluting effluent. Discharge nutrient-stripped water to waste or bottom earthen ponds.

8. Gear store for nets (keep out of sun); Food store. Laboratory/store for pH, temp, Total N, total P determinations weighing and measuring gear and record keeping.

9. Hygienic fish slaughtering (humane killing and bleeding, see Sorensen (2005)), cleaning (feed cooked offal to pigs, see Tuan, (2010)) and filleting (maybe develop fish-ball or other product from off-cuts for value added product, see Van Muoi & Nguyen (2005)), covered area with refrigeration and freezer storage?

Pond Farming Practices for P. hypophthalmus in Vietnam, Philippines, and Indonesia

Pond farming in the Mekong Delta has been transformed in twenty years from a subsistence pond culture side-line of small scale farmers providing fish locally, to a sophisticated multi-million dollar industry dominating the world fish market. Production was 7 000 tonnes in 1989 and reached 1.78 million tonnes in 2009 (Appendix 1). Although there are a large number of academic papers published on the growth and other aspects of this industry there is little discussion of the practical details of farming.

Pangasianodon hypophthalmus was introduced into Indonesia in the 1980s but has not been as successful as in Vietnam. Pond culture here is described by Herfaut (2002). The species was also introduced into the Philippines in the 1990s by the Bureau of Fisheries. In 2008 they produced a leaflet outlining the practical steps required in pond farming (Bureau of Fisheries and Aquatic Resources, Philippines, 2008).

Phuong & Oanh (2009) list the key factors for the success of striped catfish farming on the Mekong Delta. The first was the availability of good quality seed stock in adequate quantities. Seed is now available year around to farmers from the well developed hatchery industry. Hatcheries have also been developed in Indonesia and the Philippines to provide fingerlings for farming of P hypophthalmus.

1. Good Quality Seed Supply

Fry. The status of hatcheries in 2006 is described from a survey of Dong Thap province (Hung et al., 2008). An assessment of sustainability of the farming industry in 2005

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(Poisson 2005) highlighted the risk of use by all private hatcheries of an unknown Chinese product (Jin Gi, whose colouring suggests it contains banned, malachite green, methylene blue, or copper sulphate) to combat the high rate of mortality of fry. A later survey of hatcheries in three provinces in 2009 (Bui et al., 2010), shows their status has changed little over the intervening three years. Brood-stock management and practices for cross-fertilising individual breeders to maximise genetic diversity of progeny have yet to be developed and codified in practice. Here in Mount Hope we will be in the hands of whatever hatchery we can find to supply seed. Seed must be available here as you can buy live, farmed, Pangasianodon hypophthalmus in Balai Karangan market.

Fingerlings. On the Mekong Delta, specialised nurseries rear fry, 1.0 to 8.5 cm size (mean 4.5cm) from the hatcheries, to fingerling 1.2 to 20 cm size (mean 8.6cm). These nurseries are stand-alone enterprises buying fry from hatcheries and selling fingerlings to the fish farmer (Phan et al., 2010). The Vietnam government developed a state fingerling centre in 2005 to improve the quality of fingerlings available to the farming industry. Safe Quality Food standard SQF1000 a HACCP based supplier assurance code designed specifically for primary producers was implemented for state enterprises. Most of the market share in the fingerling business is privately owned and in 2008 there were still serious concerns about the viability, quality, and hygiene status of their stocks. This applies especially to residues of illegal chemicals and antibiotics use of which is not exposed in certification tests of grow-out farms (Cuyers & Van Binh, 2008).

Herfaut (2002) documented pond farming of Pangasianodon hypophthalmus in Jambi, in Sumatra Indonesia. Fingerlings released in Tankit ponds ranged from 3.8 to 7.6cm in size, and mainly came BBAT Jambi hatchery and west Java. Today fingerlings are still produced in West Java. private hatcheries provide fingerlings in the Philippines. (West Java do send fingerlings to Kalimantan)

2. Good Water Supply

The second key factor in the success of Pangasius farming that Phuang & Oanh, (2009) identified, was the importance of the plentiful supply of water from the Mekong River. A high rate of water exchange is the primary method of improving water quality. Phan et al., (2010), found that farm yield on the Mekong Delta was positively and linearly correlated with stocking density, mean pond depth, and mean pond volume; upper atchment farms had significantly higher yields than lower and those that drew water from the river rather than canals had significantly higher yields. Although they found that rate of exchange of water in ponds showed no relationship with production this must be the result of confounding factors, as water exchange is so important during the latter part of grow-out. Sorensen (2005) found that lack of water circulation in ponds, was the primary cause of discolouration of fillets as well as “off-flavour” suggesting flow as well as exchange are important.

Phan et al., (2010) show how incidence (number of farms of 89 surveyed) of six diseases is linked to monsoonal rainfall (see Figure 3). On the surface this looks like the quality of the Mekong River water deteriorates during its flood regime, which Poisson (2005) attributes the increased disease and subsequent mortality to agriculture effluents and urban waste-water. Nearly 77% farmers monitored water quality of ponds, frequency varying from daily to monthly. pH, DO, and ammonia were generally monitored using commercially available test kits and probes. During first two months of stocking, water was exchanged irregularly-from daily to weekly; in later months rate was increased gradually up to twice a day-with 30-100% replenishment. Mean yield of farms drawing water directly from the river was higher than those that drew water from canals and

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rivulets-suggesting water quality was important in production. However, yields were not correlated with water exchange frequency or the volume exchanged per week.

Figure 3. Common diseases found in catfish in the production cycle Vietnam. Rainfall (mm) are average values obtained from nine provinces of the Mekong Delta (Phan et al., 2010).

Mortality from disease varied from farm to farm on the Mekong Delta and through the grow-out cycle (Phan et al., 2010). Mortality in the first week ranged from 0-30% (mean 7%), mortality was typically 30% during the early to mid months, and then less than 10% in later months. Only three farms reported mortalities greater than 30%. Farmers reported 15 different symptoms and/or diseases, with bacillary necrosis of Pangasius spp (BNP) (Edwardsiellosis) (98% of farms), parasites (88%), redspot in flesh (61%), spot disease (58%), white gills (30%) and slimy disease (28%) were the more common diseases. BNP, parasites and white gills were the more severe diseases. BNP is recognised as an economically significant pathogen of catfish in the Mekong Delta (Crumlish et al., 2002; Dung et al., 2004), which can cause 50–90% mortality (Dung et al., 2004). The occurrence of symptoms/diseases was highest in June and July which corresponded with the onset of the wet season and increased rainfall (see Fig. 3 here from Phan et al., 2010). Clearly, this is an area that warrants more systematic pathological and epidemiological investigations. Management of health on catfish farms mainly involves chemical treatment, often with antibiotics, use feed additives (vitamin C) and regular water exchange. Farmers mainly bury or sell dead fish; we should cook ours for the pig farm.

Indonesian ponds in Tankit were constructed in 1998, they are small, around 137 m2 and only 1.5 m deep (Herflaut 2002). They dried-up in the dry season and water quality was measured and deteriorated throughout the growing cycle. DO declined from 5mgL-1 to less than 1 mgL-1 and ammonia rose from 1-2 mgL-1 to 24 mgL-1, pH was variable dropping as low as 3.9 (before adding lime) but if it is too high, above 7.0, the concentration of ammonia will become toxic to fish. Most mortality occurred in the first month; pathology was not described but disease outbreak was attributed to stress of poor water conditions, as was further mortality towards the end of the growing cycle. Good water supply is a pre-condition of site selection in the Philippines (Bureau of Fisheries and Aquatic Resources, Philippines, 2008) and they recommend water sampling through the grow out cycle:Some important water parameters to be monitored are:

Dissolved Oxygen (DO) 0.1 mg/L

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Temperature 26-30oC pH 6.5-7.5 Salinity <2ppt Water depth 1.5-2m

Pangasius is a facultative air-breathing fish, thus it can tolerate low D.O. level. The experience in Indonesia, Vietnam, as well as in Philippines emphasize the importance of having adequate supply of high quality water, for the well-being of the fish, quality of their flesh, and avoidance of stress that leads to disease outbreaks. They all emphasise the need to monitor water quality.

3. Pond preparation

Phan et al., (2010) identified the nature of the ponds and their preparation as the third key factor in the success of Pangasius culture in Mekong Delta. Fish farms here are mostly small holdings operated by the farmer/owner. Phan et al., (2010) surveyed 89 farms in the four main Pangasius farming provinces on the Mekong Delta in 2009. They averaged 4 ha in size, and averaged four ponds ranging in size from 0.2 to 2.2 ha with an average size of 0.61. Ponds are deeper than other forms of aquaculture in Vietnam, ranging from 2-6m with most being around 3.5-4.5m deep. This practice came about when ponds were constructed with higher than normal dikes to prevent stock escaping into the main river during the flood season (Phuong & Oanh, 2009). Pond size has been increasing steadily over the years as more intensive practices develop. Our 4 ponds, at 0.3, 0.06, 0.07, 0.10ha are similar to the small-scale ponds originally used to grow Pangasius; the shallower ponds at Mt Hope probably reduce the ‘cushioning’ effect of greater volumes of water on nutrient buildup, but more importantly the dykes may not be high enough to contain all the rainfall of the wet season and so let the fish escape. Indonesian ponds in Tankit were constructed in 1998, they are small, around 137 m2 and only 1.5 m deep (Herflaut 2002).

In the Mekong Delta, of 98 farms, 80% took water directly from the main river, and rest from rivulets and canals. Only 6% screened inflowing water, 3% used settling ponds, most farmers considered screening was not needed and land was too expensive to have a settling pond (see also discharge water)(Phan et al., 2010). Many farmers (57%) applied chlorine before draining the ponds and refilling. All farmers left ponds drying out and treated the pond bottom before filling, the fallow period ranged from 2-45 days, with 56% leaving ponds fallow between 7 and 15 days. Most farmers (82%) removed the sludge, more (96%) limed the bottom, most (71%) treated the bottom with salt. Newly-filled ponds were variably treated: some farmers (29%) treated them with chlorine, some (27%) with lime, some (15%) with benzalkonium chloride (BKC) and some (11%) with salt. The amounts applied were variable and did not follow a prescribed pattern (There does not seem to be a set of guidelines for this?) Guidelines for pond preparation were set out for the Philippines (Bureau of Fisheries and Aquatic Resources, Philippines, 2008):

1. Pond draining – To collect and eliminate old stocks, predators and unwanted species.2. Pond poisoning – Application of biodegradable organic materials such as tea seed

cake and tobacco dust to kill all unwanted species.3. Pond washing – To remove the effect of toxic chemicals when insecticides were

used.4. Levelling of pond bottom – Removes excess mud and dirt, to ensure complete

drainage and facilitate ease of seining during harvesting.5. Sun drying – Helps eliminate and evaporates toxic gases and ammonia especially in

old ponds.7

6. Liming – The rate of application is 100 g/m2 or 1,000kg/ha.7. Screening of water inlet and outlet – Prevent entrance of unwanted species and

escape of stocks.8. Water filling – Fill the pond with water to about 1.5m to 2m deep to provide a wide

environment for the fish.9. Basal fertilization

Types of Fertilizer Rates (kg/ha)

Organic Fertilizer (Chicken manure) 1000-2000Inorganic fertilizer(16-20-0) 100-200

Stocking Rate. In the Mekong Delta stocking densities ranged from 18-125 fish m -2

(mean 48 m-2) based on pond area, or 5-31 fish m-3 (mean 12 m-3) based on pond volume, depending on availability of seed-stock and financial ability of the farmer to purchase them. Most farms (74%) stocked ponds on multiple occasions however, within a short time frame (staggered stocking). Over 90% of the farms tested seed for uniformity of size, diseases, and vitality, 76% of farmers treat seed before stocking, 78% using salt, 32% antibiotics.

In Indonesia stocking rates were much lower, and ranged from 2.6 to 19.8 fingerlings m2

averaging 8.5 fingerlings m-2 (Herfaut 2002). In the Philippines (Bureau of Fisheries and Aquatic Resources, Philippines, 2008) even lower stocking rates were recommended for shallow ponds: 5 to 10 fingerlings m-2 with water depth of 1.5 to 2 meters. They also recommended acclimatization to avoid thermal shock that will cause mortalities of the fingerlings. The fingerlings are acclimatized by letting the plastic bag containing them float in the pond for 10-20 minutes before releasing the fingerlings. Stocking should be done early morning or late afternoon. Survivability of Pangasius is estimated to be 80-90%.

4. Feeding Management

On the Mekong Delta, 97% of farmers used commercial food purchased directly from mill (37 companies mill feed) or local merchant, 37% use farm-made feed (as well) half of which was manufactured on that farm. The quality of commercial feeds varied with protein content ranging from 20-30% (mean 25.8%) as did farm-made feed with protein content ranging from 17-26% (mean 21.6%). Moisture content of commercial and farm-made feeds was the same. Feeding rates ranged from 1 to 18% body weight day -1 for commercial feeds and 1-10% body weight day-1 for farm-made feeds. Feeding rates for farm-made feeds were generally greater than for commercial feeds throughout the production cycle. Fish were typically fed twice per day, but some farms fed up to 6 times a day (Table 1).

Table 1.Ranges in feeding rates (%body weight day-1) and frequency (mean in parentheses) in catfish farms using commercial and farm-made foods in the Mekong Delta (Phan et al., 2010).

Early months 1-2 Middle months 3-5 Late months 6-7Fish size(g) 17-150 (78) 45-1000 (337) 500-5000 (968)Commercial feed 1-18 (5.6) 1-7 (3.2) 1-5 (2.0)Farm-made feed 3-10 (5.7) 2-5 (3.9) 1-3 (2.3)

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Feeds per day 1-4 (2.2) 1-3 (2.0) 1-6 (1.8)

The food conversion ratio (FCR = amount of food used ÷ increase in biomass) for commercial and farm-made feed ranged from 1.0 to 3.0 (mean 1.69) and 1.3 to 3.0 (mean 2.25), respectively, commercial feed being significantly better. Although the yield with either source of feed was the same, the production cycle with farm-made feed was 4-8 weeks longer (Phan et al., 2010).

Harvesting. On the Mekong Delta fish were harvested at the size of 0.6 to 1.5 kg (mean 1.0 kg), after a growth period of about 6–7 months (Phan et al., 2010). The produce was sold directly to processors after negotiating for price and subjected to quality tests, particularly for banned chemicals. Processors tested samples of fish in terms of appearance, flesh colour and chemical residues prior to purchasing. Grow-out farmers often had a prior contract with processors and 89% of the farms surveyed accepted prior payment from the buyers, ranging from 10–50% of the total estimated selling price. Sometimes farmers (41%) also accepted delayed payments from the buyers, especially when there was limited demand from the processing plants. Ponds were harvested using seine nets, after draining 60–80% of the water; harvesting was generally completed within four days (up to 12 days). Buyers generally transported the harvested fish to the processing plants, either by river in the hull of boats that specialized in transportation of live fish or by road in trucks equipped with live fish holding tanks.

Farm yields varied from 70.0 to 850 t ha-1crop-1 (mean 406) or accounting for pond depth, 1.5-22.7 t.ML-1crop-1 (mean 10.4). The yield frequency distribution showed that 76% of the farms yielded 300t ha-1crop-1; very low yields, outliers on this distribution, were from farms that suffered high mortalities generally early in grow-out; very high yields (above 550) were from farms that retained stock until an acceptable market price was realised. Water consumption per ton of fish produced ranged from 07-59.7 ML t -1 (mean 6.4). Yield was positively and linearly correlated with stocking density, mean pond depth, and mean pond volume; upper catchment farms had significantly higher yields than lower and those that drew water from the river rather than canals had significantly higher yields (Phan et al., 2010).

In Indonesia, fingerlings are fed with powder for shrimps, with 40 % of protein content until the age of 1 month. In grow out ponds, fish farmers give a bigger size of feed (diameter: 2 mm), with lower protein content (about 29 %). From 2 month of age, the diameter of feed is increased to 3 mm with the same composition as the second one; protein rate is between 25 % and 30 % depending on the brand. (Herfaut 2002). In the Philippines Pangasius can be fed with pelleted commercial fish feeds (recommended for faster growth and better fish quality) at a rate of 5% of their average body weight (ABW) and will be adjusted bi-weekly down to 2.5% at end of culture period. Feed conversion ratio (FCR) averages frp, 1.3-1.8, which makes it suitable for culture. This means 1.3 to 1.8 kilos of feeds is converted to 1kg. of fish. Fish are fed twice a day (AM and PM) (Bureau of Fisheries and Aquatic Resources, Philippines. 2008). The Philippine guidelines presents the following table of age of fish, average body weight, percentage body weight fed at, and feed type used:

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Table 2. Pangasius pond culture feeding rates, Philippines (Bureau of Fisheries and Aquatic Resources, Philippines. 2008)

Days Ave. wt. range (g) % BW Feed types

1 – 15 3-10 5 Fry crumble

16 – 31 10-30 5 Fry crumble

32 – 46 30-60 4.5 Starter

47 – 61 60-90 4.5 Starter/JUV

62 76 90-150 4 Juvenile

77 – 91 150-250 4 Juvenile

92 – 105 250-350 3.5 Juvenile

106 – 120 350-450 3.5 Juvenile

121 – 135 450-575 3 Juvenile

136 – 150 575-725 3 Juvenile/Adult

151 -165 725-925 2.5 Adult

166 – 180 925-1100 2.5 Adult

Sampling Sampling is recommended practice in Philippines to monitor the growth of stocks and to compute amount of feeds to be given to the stocks for the following days. Regular sampling also allows you to see when stock has reached target weight and is ready for harvest.

Record-Keeping Record-Keeping is recommended practice in Philippines. The important data to be recorded are: daily pond activities operating cost which includes pond inputs, quantity and cost (fertilizer, fingerlings, pesticides, etc.); production data, stocking rates, harvesting; daily water parameters, ABW, pond water quality DO, Temp, pH, ammonia, etc. (Bureau of Fisheries and Aquatic Resources, Philippines. 2008). Causes of failure and success can be traced from the record which should also provide chain of custody (clearly identifying fish from fingerling source through to harvested and processed product).

5. Effect of Pond Farming on Environment-Sustainability

Based on a mean FCR of 1.69 for commercial feed, with a protein content of 25% and assuming that 30% of the nitrogen is converted to fish flesh, Phan et al., (2010) estimated 47.3 kg of nitrogen is discharged per ton of catfish produced. Using their estimates of 2007 production of 683 000 (probably 1.14 million t) approximately 32 306t of nitrogen were discharged into Mekong River. At production of 1 or 1.5 million tons, nitrogen discharge would be 47 300t and 70 950 respectively. Compared to agricultural runoff this is negligible, eg the 7.48 million ha of rice paddy in the Delta have 170-182 kg plant

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nutrients applied per ha. Phan et al. (2010) consider a comparative study of nutrient loadings from the different primary production sectors in the Mekong Delta will facilitate a more holistic management approach. De Silva et al., (2010) estimated total nitrogen and phosphorous in the effluent of farms on the Delta as 31 602 tN and 9 893 tP in 2007 and 50,364 tN and 15 766 tP in 2008. Anh et al., (2010) estimated total emissions for each tonne of fillets produced on the Mekong Delta: 740 kg BOD, 1020 kg COD, 2050 TSS, 106 kg nitrogen, and 27 kg phosphorous, 60-90% in the wastewater, 3-27% in sludge. Although total emissions from the catfish culture were less than 1% of the total TSS, nitrogen, and phosphorous loads in the Delta the authors concluded that with more efficient use of inputs and low-cost treatment and re-use of effluent streams, water pollution would be further reduced.

The Pangasius farming industry received advice on developing sustainable farming practices from both European (Poisson 2005) and US (Ish & Doctor 2007) organisations. The Vietnamese government contracted Wageningam University, Netherlands to carry out an environmental impact assessment on the Pangasius farming sector in 2008 (Bosma et al., 2009). The farmers and export and processing companies themselves were modifying their practices to meet HACCP, ISO, Eurepe GAP (Hilbrands 2010) standards to obtain export licenses to the EU and the USA (Cuyvers & Binh, 2008). These concern were expressed by the vice president of VASEP in one of the Can Tho, Pangasius Aquaculture Dialogues (Hau 2008). The concern at the impact of the explosive development of aquaculture in Vietnam, stimulated WWF to convene a dialogue of stakeholders and NGOs to develop sustainability standards (World Wildlife Fund 2008, Pangasius Aquaculture Dialogue, 2010). This culminated in the establishment of the Aquaculture Stewardship Council (ASC) to certify sustainability of aquaculture, paralleling the Marine Stewardship Council (MSC) certifying the sustainability of wild fisheries. And draft sustainability standards for Pangasius aquaculture (Hau, 2008; Wahabi, 2009; Starr 2010; World Wildlife Fund, 2010).

Proposed Mount Hope Environmental Response. I propose that we minimize effects of our aquaculture on the environment (meeting the command to “tend the garden”) and aim to meet the standards developed for sustainable Pangasius farming. We have a bound copy of these standards at Mount Hope. Apart from meeting the other standards in this document, we will seek to discharge completely pure water by growing vegetables aquaponically to strip nutrients from the effluent. I envisage using raft aquaponics (plants supported on rafts of polystyene) in long tanks (under light cover) on the other side of the road from the fish tanks.

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Figure 4. Lettuce growing in polystyrene raft showing rooting system that hangs in effluent water.Figure 5. Lettuce seedling germinated in oasis for planting in cup.Figure 6. Shallow raceways with rafts floating on surface.

Nota Bene

This is living document. Discussion on fish species to be used and developments outlined can be achieved will probably alter the plan, as other contributions are added. Appendices are still incomplete and will be provided as final information becomes available.

References

Anh, P.T., Kroeze, C., Bush, S.R., Mol, A.P.J. 2010. Water pollution by Pangasius production in the Mekong Delta, Vietnam: causes and options for control. Aquaculture Research preprint 2010

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Bosma, R.H., Hanh C.T.T., Potting, J. 2009. Environmental Impact Assessment of the pangasius sector in the Mekong Delta. Wagingen University Report 56pp.

Bui, T.M., Phan, L.T., Ingram, B.A., Nguyen, T.T.T., Gooley, G.J., Nguyen, H.V., Nguyen, P.T., De Silva, S.S. 2010. Seed production practices of striped catfish, Pangasianodon hypophthalmus in the Mekong Delta region, Vietnam. Aqaculture 306, 92–100.

Bureau of Fisheries and Aquatic Resources, Philippines. 2008. Culture of Pangasius spp.Cuyers, L., van Binh, T. 2008. Aquaculture export development in Vietnam and the

changing environment: the case of Pangasius in the Mekong Delta. Centre for ASEAN Studies. Discussion Paper 59, 27pp.

De Silva, S.S., Ingram, B.A., Nguyen, P.T., Bu T.M., Gooley, G.J., Turchini, G.M., 2010. Estimation of Nitrogen and Phosphorus in effluent from the Striped Catfish farming sector in the Mekong Delta, Vietnam. Ambio 39, preprint 2010.

Hau, V.P., 2008. Sustainable development of Pangasius Farming: View of the producers. Pangasius Aquaculture Dialogue Can Tho. 18pp.

Hau, V.P., 2008. Sustainable development of Pangasius Farming: View of the producers. Pangasius Aquaculture Dialogue Can Tho. 18pp.

Hau, V.P., 2008. Sustainable development of Pangasius Farming: View of the producers. Pangasius Aquaculture Dialogue Can Tho. 18pp.

Herfaut, J., 2002. Conditions and perspectives of rural breeding of Pangasius hypophthalmus in Jambi (Sumatra, Indonesia) Comparison between two production systems: floating cages and ponds. Institut de Recherche pour le development-Indonésie 23pp.

Hilbrands, A. 2010. European Food Retail Aquaculture Certification Initiative (EurepGAP). SGS Group Website 8pp.

Ish, T., Doctor, K. 2005. Farmed River Catfish, Swai (Pangasius hypophthalmus) Basa (Pangasius bocourti) Final Report 2005 (updated 2007). Seafood Watch Seafood Report, Monterey Aquarium. 29pp.

Pangasius Aquaculture Dialogue, 2010. Meeting Summary, Can Tho. Pangasius Aquaculture Dialogue 15pp

Pham, L.T., Bui, T.M., Nguyen, T.T.T., Gooley, G.J., Ingram, B.A., Ngyen, H.V., Ngyen, P.T., De Silva, S.S. 2010. Current status of farming practices of striped catfish, Pangasianodon hypophthalmus in the Mekong Delta, Vietnam. Aquaculture 296, 227– Hau, V.P., 2008. Sustainable development of Pangasius Farming: View of the producers. Pangasius Aquaculture Dialogue Can Tho. 18pp.

Phuong, N.T., Oanh, D.T.H. 2009. Striped Catfish aquaculture in Vietnam: A decade of unprecedented development. Pp 133–149. In: Success Stories in Asian Aquaculture Eds De Silva, S.S., Davy, F.B., NACA, IDRC, Springer, Dordrecht Heidelberg London New York.

Poisson, G. 2005. Pangasius farming practices in Vietnam. A study in view of sustainability issues. Deutsche Geselschaft für Technishe Zussammenarbeit GTZ/Binca PPP Programme Report. 38pp.

Sorensen, N.K. 2005. Slaughtering process for farmed Pangasius in Vietnam. Norwegian Institute for Fisheries and Aquaculture Research Report 12, 43pp.

Starr, P. 2010. Global catfish standards imminent as Pangasius Aquaculture Dialogue winds up. Catch & Culture 16 (1) 26–30.

Tuan, T.T. 2010. Tra Catfish (Pangasius hypophthalmus) residue meals as protein sources for growing pigs. Swedish University of Agricultural Sciences, Uppsala. MSc. Thesis. 35pp.

Van Muoi, N., Nguyen, N.T.T. 2005. Apply gel properties of protein in processing fish balls from abundant raw material in Mekong Delta: Pangas Catfish (Pangasius hypophhalmus). Food Technology Report, Can Tho University. 5pp.

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Wahab, M.A. 2009. Bangladesh Workshop Theme. Pangasius Aquaculture Dialogue Bangladesh 13pp.

World Wildlife Fund, Website 2008. Farmed Pangasius.World Wildlife Fund 2010. Pangasius Aquaculture Dialogue Standards. WWF Website

55pp

Appendices:

1 Review of published reports on Pangasianodon hypophthalmus 20pp2 Review of published reports on Tilapia 4 pp.3 Review of published reports on Aquaponics 2pp.

John Cranfieldj.cranfield@clear.net.nzSaturday, 6 May 2023

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