Brackishwater pond (tambak) aquaculture in Indonesia is an important livelihood activity in coastal areas, but many small-scale farmers struggle to continue farming shrimp. Viral diseases cause crop losses, and input costs (particularly for feed) are rising while prices for shrimp are declining due to strong competition in a global marketplace. Thus many farms are out of production or producing only limited quantities of shrimp. Recent ACIAR-funded research revealed that while small-scale shrimp farms predominate in South Sulawesi they only contribute about 5% of total provincial shrimp production. While some farms now utilise Better Management Practices (BMPs) for shrimp farming to overcome production constraints, successful implementation depends on meeting specific site-related, socioeconomic and logistical criteria. A large proportion of farms that will fail to meet the criteria required for shrimp BMP implementation will need alternative production strategies if they are to remain (or become) viable.
This project will test and evaluate the economic viability of alternative commodities for brackishwater pond culture such as tilapia, milkfish, grouper, crabs and sea cucumbers. It will involve evaluation trials in South Sulawesi and Nanggroe Aceh Darussalam (Aceh) provinces to build on the outcomes of previous and ongoing ACIAR projects. The work will also encompass mariculture development on offshore islands of Nanggroe Aceh Darussalam province, particularly Pulau Simuelue. Trials on lobster puerulus collection and grow-out will be undertaken with support from another ACIAR project studying spiny lobster aquaculture development in eastern Indonesia, Vietnam and Australia. Additionally, growth trials with grouper will be undertaken in collaboration with the fish seed production centre on Pulau Simuelue to promote the use of more sustainable culture practices developed in other ACIAR-supported work.
Overall project progress has been delayed by delays in registering the project in DIPA (Daftar Isian Pelaksanaan Anggaran - Agreed Activity Implementation Budget). Because DIPA registration and bank account approval could not be completed until late 2010, many activities could not be carried out in 2010 and have been delayed until 2011. This has led to a delay in implementing most project activities of around 1 year.
Trials with tilapia and milkfish in Aceh had mixed success with 3 out of 9 farmer-managed ponds failing due to high salinity. Of the remaining ponds, 1 research pond and 3 farmer-managed ponds demonstrated economic returns comparable with traditional shrimp farming. Two research ponds and two farmer-managed ponds achieved a return less than the project’s reference for traditional shrimp farming (i.e. IDR 1 million per hectare per cycle) and one farmer-managed pond provided a net negative return (loss). In general, tilapia performed better at salinities <20 ppt, whereas at higher salinities milkfish tended to perform better.
In South Sulawesi, tilapia trials were commenced in March - April 2011 at Bonto Bahari and Salenrang in Maros District, and Kanaungan in Pangkep District.
Farmer response to these trials has been positive, with farmers interested in trialling tilapia culture. Some farmers are planning to alternate dry season production of shrimp or milkfish with wet season production of tilapia.
Soft-shell crab culture training was undertaken in Aceh in May 2010 in Aceh Timur, Aceh Utara, Bireuen and Aceh Besar districts. Market price remains a constraint to the expansion of soft-shell crab aquaculture in Aceh.
Lobster puerulus collectors were established at 3 sites in Pulau Simeulue in Aceh. After two months, no puerulus had been collected. However, local fishermen noticed that puerulus had settled on fish cage nets and small juveniles could be collected from coral rubble habitats. Rough weather damaged or destroyed most of the collectors. They have subsequently been replaced with a more robust design, or the collector material relocated to net cages.
Future trials in 2011 will evaluate tilapia and swimming crabs in South Sulawesi, and continue to develop brackishwater culture of tilapia in Aceh.
Trials with Nile tilapia (Oreochromis niloticus) either alone or co-cultured with milkfish (Chanos chanos) in Aceh have demonstrated that tilapia cultured in low-salinity (<20 ppt) brackishwater ponds can provide income to farmers comparable with shrimp culture. Out of a total of 22 trials to date, 9 ponds (41%) have met or exceeded our reference profitability of IDR 1-5 million per hectare per crop (Fig. 1). Fourteen ponds (64%) have been ‘profitable’, i.e. have generated positive economic returns. This figure is similar to the profitability figure for traditional shrimp ponds (64-73%), indicating that Nile tilapia culture in brackishwater ponds provides economic returns similar to traditional shrimp culture.
Farmer response to the trials in both Aceh and South Sulawesi has been positive. Several farmers in Aceh are now alternating cropping shrimp (dry season) with tilapia (wet season) to reduce the risks of wet-season disease outbreaks in shrimp. Farmers in South Sulawesi have formed a farmer group, supported by project participants, to provide support to new tilapia farmers and provide a resource for the more widespread introduction of tilapia culture.
Two cycles of pond trials with swimming crab (Portunus pelagicus) co-cultured with milkfish and the edible seaweed Caulerpa have been undertaken in South Sulawesi. Profitability of these trials was negative or, at best, marginally positive due to problems harvesting the swimming crabs from the ponds. In response, we are collaborating with staff of the Faculty of Marine Science and Fisheries at Hasanuddin University, Makassar, to develop better techniques for harvesting swimming crabs in traditional ponds.
The crab polyculture trials have shown that culture of the edible seaweed Caulerpa is highly profitable, mainly due to the low requirements for inputs to seaweed culture and a strong local market in South Sulawesi where Caulerpa is consumed as a salad vegetable. Consequently, the project will increase its focus on this commodity.
Assessment of lobster puerulus resources in Aceh is being carried out in collaboration with SMAR/2008/021 ‘Spiny lobster aquaculture development in Indonesia, Vietnam and Australia’. Lobster puerulus collectors have been established at four locations on Pulau Simeulue, which has an existing lobster fishery and established market linkages. At three of these locations few or no puerulus were caught. The fourth site on the west coast of Pulau Simeulue (Desa Latak Ayah) seems to have reasonable puerulus settlement but is very remote from the main township and difficult to monitor. Pulau Breueh, near Banda Aceh, also seems to have good puerulus settlement and future research will focus on Pulau Breueh.
Development of grouper grow-out at Pulau Simeulue has been constrained by poor availability of fingerlings from the local Coastal Fish Seed Production Centre (Balai Benih Ikan Pantai - BBIP). An assessment of the production constraints at BBIP Simeulue in October 2011 indicated that problems with microalgal production were limiting production of rotifers used as initial feed organisms for the grouper larvae. In response, the project supported a post-graduate student from the Faculty of Fisheries and Marine Science, Sam Ratulangi University, Manado, North Sulawesi, to provide training to BBIP Simeulue staff in culturing rotifers without microalgae, using simple and cheap culture techniques. Further evaluation of constraints to fingerling production, and additional training, will be undertaken in conjunction with BBIP Simeulue staff.
Dr Ageng Herianto (Department of Agriculture, UGM) supervised a socio-economic assessment amongst 31 farmers in the community of Kanaungan village, the site of Nile tilapia culture trials in South Sulawesi. This study concluded that while trial / demonstration ponds are an effective extension method to introduce and support the diffusion of new technologies, farmers still lack confidence in farming Nile tilapia due to a lack of previous experience, and that continued support and provision of technical information is necessary to build up their confidence. One way to support technology diffusion to farming communities is to use a small group or ‘clique’ to transfer learnings to potential adopters.
In addition to the UGM study, discrete socio-economic studies were carried out by students from the Faculty of Marine Science and Fisheries at Hasanuddin University, Makassar, supervised by Dr Mardiana E. Fachri. The three studies evaluated communication mechanisms amongst farmers involved in Nile tilapia trials, described economic aspects of Nile tilapia and milkfish culture in ponds, and evaluated the market potential for Nile tilapia in South Sulawesi.
The project has made substantial progress in trialling and tracking farmer adoption of alternative commodities for pond (tambak) farming in Indonesia. Trials with Nile tilapia (Oreochromis niloticus) demonstrated that, from a total of 79 tilapia trial ponds, 38 ponds (48%) were ‘profitable’, i.e. gave a positive financial return. Twenty-three ponds (29%) were ‘successful’, i.e. gave a return greater than our reference value of IDR 1 million per hectare per crop cycle. The major problems experienced with tilapia culture have been: flooding of ponds during the rainy season, leading to crop losses; high salinities during the dry season causing outbreaks of Streptococcus and reduced growth in the tilapia; poor pond preparation by farmers, leading to ‘contamination’ of trial ponds with mujaer (Oreochromis mossambicus).
Trials with swimming crab (Portunus pelagicus) were less successful due to high rates of cannibalism and the difficulty in harvesting crabs from the ponds.
The edible seaweed Caulerpa proved to be a highly profitable option for smallholder farmers in Laikang district of South Sulawesi. Twenty of the 24 ponds involved in this trial were profitable, with many generating profit far in excess of our reference revenue of IDR 1-5 million per hectare per crop. One farmer generated revenue in excess of IDR 60 million in the period February - October 2012, and used the money to build a new house.
A range of samples of Caulerpa from production ponds and from island sites were analysed to check the levels of metals in the seaweed to assure the food safety of this commodity. Levels of arsenic, cadmium, mercury, lead and tin were all below the limits set by the Indonesian National Standardisation Agency.
Alternative commodities (tilapia, swimming crab, Caulerpa) have been adopted by 51 farmers in Aceh and 83 farmers in South Sulawesi. The Brackishwater Aquaculture Development Centre Ujung Batee has supported the establishment of farmer-managed tilapia nurseries at 5 locations in Aceh province. These hatcheries / nurseries distribute tilapia seed to local farmers, supporting the expansion of brackishwater tilapia farming in Aceh. This approach appears to be a useful model for development and expansion of aquaculture commodities in areas lacking effective large-scale extension and technical support services. The project is undertaking socio-economic studies of tilapia farmers in Aceh and in South Sulawesi to better understand the benefits and constraints of adopting these commodities, in order to facilitate technology adoption by smallholder farmers.
A socio-economic survey of tilapia farmers in Aceh (including project participants and non-participants) showed that farmers were generally positive about tilapia culture and listed positive attributes as: easy to grow, low risk, and more profitable than milkfish. Some farmers pointed out that tilapia could be polycultured with other species or alternated with shrimp crops (wet season tilapia, dry season shrimp).
The project is developing land suitability maps for project sites in South Sulawesi, to evaluate the usefulness of mapping as an advisory tool. The study is using ALOS satellite imagery, with field data collection based on 1:25,000 scale topographic maps. Preliminary maps have been developed based on field survey data and input from pond trials for specific commodities. Because of drastic seasonal differences in the study sites, suitability maps are being developed for both wet and dry seasons.
Studies of market supply chains have been undertaken for Aceh (milkfish and tilapia) and South Sulawesi (milkfish and rabbitfish). In South Sulawesi, milkfish is an everyday commodity and has a larger volume market but lower price than rabbitfish. In contrast, demand for rabbitfish is primarily from restaurants.
Assessment of lobster puerulus resources in Aceh has been undertaken at three locations on Pulau Simeulue, which has an existing lobster fishery and established market linkages. No puerulus were found on the collectors located close to the main centre (Sinabang) which could easily be monitored. Villages in the north-western part of the island report good puerulus settlement, but it is difficult to monitor these remote locations effectively. In 2012, the project moved the collection site to Pulau Breueh, near Banda Aceh. There have been catches of lobster puerulus from this site, and reports of some development of lobster culture at Pulau Breueh.
The project provided training in simple rotifer production techniques by Sam Ratulangi University (Manado, North Sulawesi) to the Coastal Seed Production Centre at Pulau Simeulue, Aceh. Although these techniques have been adopted, and have reportedly substantially improved rotifer production, it is yet not apparent whether this has translated to improved fingerling production.