Intensive shrimp farming

The output of intensive shrimp farming represents approximately 80% of total shrimp production in Vietnam. Intensive shrimp farming is the dominant farming system used in coastal areas, such as Soc Trang and Bac Lieu in the Mekong Delta and in the central coastal areas of Vietnam. The production area under intensive practices is estimated to be around 61,000 hectares. Farmers in Vietnam grow both Penaeus monodon (black tiger shrimp) and Litopenaeus vannamei (whiteleg shrimp) in intensive system. However, many farmers tend to shift to the culture of Litopenaeus vannamei when they have sufficient access to finance and input materials.

Key features
Average stocking density

L. vannamei: 90 PL/m2
P. monodon: 35-40 PL/m2

Average productivity

L. vannamei: 6-15 tonnes/ha/year
P. monodon: 2-8 tonnes/ha/year

# of crops per year

2-3

# of days per crop

L. vannamei: 90-100 days
P. monodon: 110-140 days

Harvesting season

All year round with peaks from February to March (Mekong Delta), June to July (central Vietnam) and from September to October (both areas)

Type of farmer

Small-scale farms and corporate farms

Potential risks
  • At farm use of antibiotics and chemicals
  • Product adulteration after harvest
  • Water pollution of adjoining water bodies
  • Neighbourhood conflicts due to resource exploitation and water pollution
  • Long and complicated supply chains

Type of farmers

Intensive shrimp farming is practiced by both individual households and corporate farms. Farms can be small (1-3 ha) for individual households or large (from a couple of ha to 1000 ha) for corporate farms. Most shrimp processors and exporters nowadays have invested in one or more shrimp farms in which they invest in terms of sophisticated production methods and e.g. certification. With their own shrimp farms, processors and exporters are able to secure a minimal stability of raw material supply to their processing establishments. Although some smaller farms are organized in associations and directly linked with processors, many operate independently and are linked to processors only through a network of intermediaries.

Production and harvesting system

Shrimp are raised in earthen ponds with sizes ranging from 0.2 to 0.5 ha. In intensive farming, farmers need to maintain bio-security in order to manage the risk for disease outbreaks in the earthen ponds. This requires proper pond preparation and the use of biosecurity measures such as the use of lining, bird protection, crab protection and other predator control systems.

Farmers use various types of conventional and more high tech farming methods (e.g semi and full biofloc). Conventional systems can potentially give better results but also have higher risks. The newer technologies often require less commercial feed as input but more input in terms of aereation and bio-security (e.g. liners).

Grow-out takes 90-100 days for L. vannamei and 110-140 days for P. monodon. In intensive shrimp farming, farmers generally harvest the entire production at the same time. Target sizes are normally smaller than in traditional systems. This has two reasons. First, shrimp growth slows down after it reached a certain size and production gets more expensive due to higher feed conversion ratios. Secondly, after they reach a certain size shrimp become more prone to diseases which increases the risks for farmers. Farmers harvest sizes range from 100-120 HOSO/kg for L. vannamei and  30-50 HOSO/kg for P. monodon.

Target species and byproducts

L. vannamei is increasingly dominating intensive shrimp production as many farmers are switching from P. monodon to L. vannamei, due to higher yields. Farmers practice monoculture so there are no other byproducts in intensive shrimp farming.

Stocking densities and productivity

The main stocking season is January/February, but it is common for farmers to stock their ponds with hatchery PL throughout the year. The average stocking density of L. vannamei is 90 PL/m2, which leads to an annual production of 6-15 tonnes/ha/year. Stocking densities of P. monodon range from 35-40 PL/m2, and produces an output of 2-8 tonnes/ha/year.

Use of seed, feed and other inputs

Farmers stock their ponds with hatchery PL, which are generally screened for viruses before stocking. There are many small and large scale hatcheries in Vietnam but quality of PL varies widely. Large enterprises control the entire production cycle and are able to produce their own quality seed and PL. Other farmers have to buy their PL from traders. For L. vannamei, it is common to nurse PL in a nursery pond before they are stocked in a grow-out pond.

Farmers use commercial pellet feed. Feeding is done either manually or via an automated system. Chemicals such as medicines and additives are a problem, since they are readily available to farmers and usage is often pushed for by traders. Many farms prefer probiotics instead of chemicals or a mix of both.

Seasonality

Shrimp production in intensive systems can be practiced all year round in most production areas. The main harvesting seasons are from February to March and September to October in the Mekong Delta. Peak harvesting seasons in central Vietnam are from June to July and from September to October.

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