The Tradisional Prawn Farming

in Sidoarjo, Indonesia

email : harry@atina.co.id

1)   Background

The traditional aquaculture in Sidoarjo, East Java was started about 200 years ago. Sidoarjo means city of "prawn" and "Bandeng (called Milkfish in English). Farmers in Sidoarjo has been culturing and supplying fish and prawn with their unique traditional aquaculture method, called "poly-culture farming of prawn and milkfish". Now days, they raise prawn and fish in safety food manner and supply them to international as well as local markets.

2)   Production Area

All of ponds are located in brackish area. In this area, water is regularly changed by opening water gate at the time of tidal movement. Typical pond unit compose of one reservoir, one mix pond, and several grow out ponds. Seed is usually released in an adaptation pond, which is a special area constructed inside the grow-out pond.

When the prawn is growing, the gate between each growth out pond will be opened, so the prawn can be spread out to all of the compartments. Average area for one unit of pond is 10 ha. There is no fence around the pond, so local people can freely access to the river.

3)   Culture Method and System

a.  Poly-culture farming

The main production from their traditional aquaculture was Milkfish for more than 200 years in the area. Then, Prawn farmers started to selectively catch Milkfish seeds and release to the pond, while the seeds of Tiger Prawn and other species entered the pond by the water inlet.

	b.  Natural Aeration 									
	

Milkfish stimulate water movement and aeration by actively swimming around, so there is no need for artificial aeration.

c.  Water exchange

Because of the special geographical condition in Sidoajo, there is 2 to 3 meters tidal difference in the area, which makes it possible to fill and drain water without pumping.

d.  Earthy feed

No artificial feeding and medication are used in this system. Instead, farmers stimulate plankton growth by cultivated seaweed or algae and let it decay through collecting and drying.

e.  Input

There are some inputs into the ponds. The name and purpose of the inputs are followings.

Lime                            : use during drying the pond

Fertilizer                      : small quantity of fertilizer is used to stimulate seaweed growth.

Natural ichthyocide       : small quantity of saponine usually use to eliminate predatory fish

Mangrove leaf or grass  : stimulate plankton growth especially when the seaweed is not enough.

f.  Stock density

In some situation, especially in rainy season when the salinity is low, farmers buy juvenile prawn or milkfish, which are produced by other farmers group. Appropriate number of stock for this system is 1 to 2 prawns per m² .  

g.  Waste Management

As there is no additional artificial feed, so outlet water quality is not controlled. The only waste is mud that enter the pond by inlet water. They dump the mud to the dike or canal when the pond is dried.

h.  Intensive Management

Although it is a non-intensive method in the term of stock density, there is intensive management work and experience need to do and decide for each step. The prawn is harvested in 105 to 120 days after release, while milkfish is harvest in 7 to 12 months.

This farming method yields low production but assure a sustainable benefit for prawn farmers, local society and environment of the area. Furthermore, it produces premier quality of Black Tiger Prawn.

4)   Harvesting method

There are three major stages of harvesting in the area. First, harvesting is being with bamboo-made tool. Second, farmers collect prawns by hand-catching or net-catching. Lastly, neighbors join in the harvesting.

At the first stage, farmers regularly use bamboo-made trap called "Prayang" for harvesting which collect around 80% of the prawn at the first harvesting stage. Then they continue harvesting by hand-catching or net-catching. Participatory harvesting by the community people is traditional method at the later stage of harvesting..

5)   Transportation System

Harvested prawn and fish are selected in pond site before move to the factory by motorcycle or boat.

7)   Internal Control System

Internal and Quality Control System composed of internal field inspectors, field officers, quality controllers, and approval committee.

8)   Social and Environmental Consideration

Traditionally, farmers invite community people to the last harvest. The local people are also allowed to fish wild species in the pond area. So, there is mutual respect and social balance between local society and farmers.

Thus, this condition is different from inclusive farming system, where social conflict is usually happen.

Interest and integrate use of mangrove in this production system assure the sustainability of Mangrove. It is a tradition of this area to plant mangrove species, like: Avicennia to strength the dike, while other species like: Rhizophora is planted along the river bank and seashore. Mangrove leaf is also used to stimulate plankton growth.

~~HR~~

Natural Environment Impact

Conservation and preservation of mangrove could not be achieved if it is undertaken in such way that neglects local people desire to seek a better living. Interest and integrated use of mangrove in this production system assure the sustainability of the mangrove. The mangrove is planted to strength the dike, river-bank, and seashore. Mangrove leaf and grass used to stimulate plankton growth. However, destruction of mangrove preservation area, conversion of agriculture land to shrimp farm, illegal land use, and degradation of environment quality are a common phenomenon in the area, thus we have to regulate the condition by setting standard for land ownership and mangrove restoration program.

Socio-economic impact

The socio-economic sustainability of this system is good, because it is more labor intensive rather than capital intensive. Lots of workers are required during harvest, maintaining, and cleaning ponds. Traditionally farmers let community to join “Buri” which is the last harvest and the most important is that the project treats farmers as a subject, not an object.

Since many hatchery shifting to others species production, supply for black tiger seed getting difficult for shrimp farmers.

Therefore, together with support from farmers ATINA establish own hatchery start on October 2009 located on Situbondo, East Java - for providing and support shrimp farmers for good quality of baby shrimp.

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  General information about the Black Tiger :

The shrimp is basically not fully domesticated, there is no or little breeding and production is relying either on wild caught Postlarvae or Postlarvae from hatcheries that are using wild caught parents. The Tiger shrimp is the most important commercial shrimp with around 55 % of the world market (FAO 1996).

The production of Tiger Shrimp is organised so that Postlarvae (PL) are supplied by either hatcheries or by wild-catch. Sometimes Juveniles are raised in intermediate nurseries.

An overview of steps in the production :

Stages refer to the number of development stages, N5 means 5^th stage of Naupli. 

The total length of a production cycle is 22-25 days. The shrimp is moved between different tanks depending on their stage of development.

Skletonema is plankton. It is produced by the hatchery itself. It is multiplied from small batches in the laboratory in bigger and bigger batches. The plankton is fed with chemical  nutrients/fertilisers.

Sea Water is used. It is filtered with sand and active charcoal. After that it is treated with 15-20 ppm Ca(OCl)₂ (Hypo chlorite) and Na₂S₂O₃ for neutralisation (pH 8.3). Water is changed 30% per day in Naupli stage, 75% during PL1-4 and 100% from PL5 stage. Used sea water is returned to the sea without further treatment.

PL is harvested at night with the help of light (shrimp moves in the direction of light). On shipping the PL are put in oxygenated water. Some Artemia is added as feed during transport.

Gelondongan Production

Gelondongan is the name of a juvenile shrimp that has been raised 14-20 days after the PL stage. Many of the farmers have problems to get a sufficient high salinity for the shrimps in their early development stage, as they are relying on the tides. In particular this problem occurs in the rainy season. Therefore PL are raised in a special operation and thereafter distributed to the farmers. Approximately 80% of the farmers use Gelondongan in the rainy season and 30% in the dry season.

The production schedule is like this:

• 10 days the pond is dried and cultivated
• It is filled with water for 5 days so that plankton grows
• Thereafter the PL are put in (250 000 per dam - although as the size of the dams vary that is probably a rather rough figure).
• Shrimps grow for 14-20 days
• At harvest the dam is emptied through a pipe that lead into a sieve and the small shrimps are collected. They are packed in plastic bags filled with water and additional oxygen and driven to the producers.

After three such cycles the ponds are dried for a longer period.

~HR~