AQUA 2012: Feasibility of Transforming Shrimp Ponds in the Mahakam Delta to a Sustainable Aquaculture System17 September 2012
Roel H Bosma of Wageningen University, Netherlands has modelled the financial feasibility of transforming extensive shrimp ponds in the Mahakam delta, Indonesia, into sustainable aquaculture ecosystems, writes Lucy Towers, TheFishSite Editor, from AQUA 2012, Prague, Czech Republic.
Over the years, the Mahakam delta has attracted poor migrants from nearby islands. With very few employment opportunities, local people are relying on the delta for a source of food and income.
Shrimp production in the delta took off in 1999 with around 75 per cent of the delta being used for shrimp ponds.
However, by 2006 a third of ponds were not producing and the average prawn yield had dropped to under 50 Kg/ha/year.
Diseases, such as white spot, combined with deteriorating water quality, poor pond design and the lack of investment and knowledge, have led to production losses and subsequently, the loss of farms.
By 2008, only 54 per cent of the delta was been used for shrimp farming.
In order to try and help farmers set up a more sustainable and reliable aquaculture system, Mr Bosma has looked at the use of the 'greenwater technology shrimp system'.
This organised system is currently in use in the Philippines, where mangrove cutting has been banned since 1982, and has proved successful, with many farms crossing over to the system. The abundance of mangroves within the system has been shown to reduce disease.
Following this success, Mr Bosma has calculated the feasibility of using this green water system for shrimp culture in the Mahakam delta, in combination with mangrove forestry.
Cost benefit analysis for a farm area of 11 ha with shrimp prices at $6.4 per Kg was used to calculate feasibility.
Two systems were tested, one which was extensive shrimp farming and the other which incorporated mangrove forestry with shrimp farming at a 7/1 ratio (the greenwater technology method).
The project found that the mangrove/shrimp system doubled farmers profits over the extensive shrimp system. It also produced 20 times more shrimp, with 11,000 kg/11 ha compared to 500 kg/11 ha.
Mr Bosma concluded that the greenwater shrimp system could be feasible for the Mahakam delta.