(Thefishsite) Stuart Lumb, contributor to TheFishSite, visits the Mekong Delta in Viet Nam to look at catfish production. Fish farming and the Mekong Delta are synonymous - when you want to see fish farming in the country you have to travel to this part of Viet Nam. This complex delta system is contained in a triangular area to the west of Ho Chi Minh City, with many of the villages in the delta connected by water rather than by roads.
The Mekong river is the 12th largest in the world and south east Asia's longest river, with an estimated length of 4350km, rising in China and flowing though Myanmar, Laos, Thailand, Cambodia and finally Viet Nam.
Several large dams have and are being built along the Mekong to generate hydro electric power. Daming the mighty Mekong will also change the river's natural flood-drought cycle, eventually impacting on fish production in the delta.
My guide and translator was a Vietnamese vet , Dr Nguyen Hoang Vu and our first appointment was at a feedmill owned by Vinalivesco. The company is owned solely by the State and is not a joint venture operation, as many are in Viet Nam. Whilst being state owned, private investment is allowed in the company. The mill which produces 50,000 tons of aqua feed per annum is the only one of its kind in the delta.
Viet Nam prides herself on the quality of her catfish which is superior to fish from other major producing countries. It can be used in 50 different recipes which makes it a very versatile fish for the dinner table. Catfish producers don't receive any help with exports from the government, neither do they receive any government subsidies, unlike Chinese producers. .Exports in 2011 are up on the previous year. Tariffs, however, have caused problems with exports to the USA but fortunately the EU imports large amounts of catfish along with South American countries.
Feed accounts for 80-90 per cent of the costs of production. Fingerlings are fed a 36 per cent crude protein (CP) diet. The protein levels in the feed decrease as the fish get older, with a 26 per cent diet being fed just prior to harvesting, with overall feed conversion a very respectable 1.5:1. Fishmeal is used in diets but is expensive, hence around 50 per cent of the protein is sourced from soyabean meal (not full fat soya ) and rice bran. Synthetic amino acids are also used in diet formulations. A requirement for exporting catfish is that growth promoters are not allowed to be added to feeds and even natural ones are banned from diets. In the event of disease outbreaks, the problem can be treated by putting antibiotics into the ponds.
The first farm visited was cropped every six months. It consisted of a number of ponds running parallel to each other. A small board displayed the pond number and its stocking date. This date could then be checked regularly by the farmer with regard to the feeding regime and to decide when to change the feed.
In order to keep the fish oxygenated, a channel carrying fresh water ran at right angles to the ponds . This channel was slightly higher than the ponds so that water could flow in by gravity. At the opposite side of each pond was an overflow pipe which was positioned so that the water level remained constant. Feeding is all carried out by hand and very laborious as all the feed is contained in 40kg bags, which is double the maximum weight allowed in the UK.The bags of feed are positioned on a small rectangular wooden raft over which is a rope which runs right across the pond. At feeding time the farmer simply hauls the raft to the desired position and then empties each bag into the water. All very simple but extremely effective.
Then it was on to the second farm. We had left Ho Chi Minh City in a tropical downpour, driving at high speed along one of Viet Nam's new toll motorways. This evolved into the usual two way pot-holed tarmac highway which we drove on for around two hours. The road then narrowed, with the last 4 km being a single width strip of concrete which came to a dead end around 400m from the edge of a tributary of the Mekong.
Standing there I looked across the water and just beyond the far bank was a small building which was the farm's feed store. Beyond that was the fish pond. Moored to the river bank was a rather small canoe. A grinning boatman gestured at to me to clamber in, festooned with my camera bag and notebook and despite doing my best efforts to capsize it I miraculously ended up on the other bank completely dry.
The pond had an area of 6000m2 and had no fresh water inlet, hence a floating diesel powered aerator was humming away merrily injecting air into the water. The pond was soon to be harvested, yielding catfish weighing on average 1.2kg and a total yield of 600tons of fish. As at the other farm feeding was a laborious manual operation.
Again, feed was in 40kg bags and these were manhandled from the feed store and placed end up in a canoe. Feeding was a three man operation. One farmer paddled the canoe out into the middle of the pond, whereupon two other farmers emptied the bags swiftly into the water, with the fish causing the water to foam as they fought for the feed pellets.
Feeding takes place twice daily and all in temperatures of 30c and high humidity. All the feed has to be transported to the fish farm in bags, in large canoes, after which the bags are taken off the canoe and carried to the store . Finally the feed gets shipped out into the pond at feeding time. Fuel for the aerator is also brought in by hand and I doubt very much that when consumers in the USA and the EU tuck into their catfish steaks they are aware of the huge amount of calories and sweat expended by these industrious Vietnamese fishermen in tending their crop and providing fish for the table.
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