Semi-intensive L. vannamei farming

The lion’s share of all shrimp farms (i.e. for both Peneaus monodon and Litopenaeus vannamei are semi-intensively farmed in India. These farm systems are found along the entire Indian coastline. Many of the semi-intensive L. vannamei farms are clustered together. In this way, enabling them to take advantage of shared effluent treatment systems (ETS) or biosecurity measures. In order to transform from extensive techniques to semi-intensive techniques certain modifications are needed. These adjustments include, clearing and levelling the pond bottom, digging a canal in the pond bottom, converting from tidal water exchange to pumped water exchange, controlling stocking density, using more fertilizers and providing shrimp feed. When these requirements are fulfilled, the farms are eligible for CAA registration. Farmers need an additional permit when they want to export their L. vannamei shrimps.

Key features
Average stocking density

11-69 PL/m2

Average productivity

10.6 tonnes/ha/year

# of crops per year

2 to 3

# of days per crop

85-175 days

Harvesting season

Andhra Pradesh and Tamil Nadu: All year round

West Bengal: May to August and September – December

Orissa: April to May and September to November

Type of farmer

Small to medium sized farmers

Potential risks
  • use of antibiotics
  • salinization of agricultural lands
  • supply from unregistered farms

Type of farmers

In 2014 50,240 ha was under culture of L. vannamei. In 2015, the farm area expanded further as almost all farmers with semi-intensive production systems have shifted to L. vannamei. Only 900 farms and clusters of farms with a total farm area of 9,000 ha are legally registered with the Coastal Aquaculture Authority (CAA). CAA approved farms are required to take several bio-security measurements such as bird fences and usage of water intake reservoirs and effluent treatment systems.

Out of the 900 CAA approved farms more than 500 are clusters that accommodate a total of 2,500 small-scale farmers. Farming of L. vannamei is concentrated in Andhra Pradesh but also takes place in the other states along the east coast and in Gujarat.

Production and harvesting system

Average pond size in semi-intensive L. vannamei systems vary from 0.2 to 0.5 ha. There is a regular water exchange through pumps and canals. Most farms do not use water reservoirs for water intake or treatment tanks for water outlet. The duration of cultivation at the CAA approved farms varies from 85 up to 175 (average 119) days depending on the target harvest size. The ponds are emptied completely at the time of harvest. On average shrimps are harvested at 26 grams with a range from 18 to 35 grams. Survival rates in this systems is quite high, ranging from 78% to 98%.

Target species and byproducts

In this system only L. vannamei is cultured.

Stocking densities and productivity

Stocking density ranges from 0.11 to 0.69 million post-larvae per hectare. The average annual productivity from CAA approved farms was 10.6 tonnes per hectare with a range from 6.42 to 17.5 tonnes per hectare in 2014.

Use of seed, feed and other inputs

Farmers use post-larvae from hatcheries. These are often located in Andhra Pradesh and Tamil Nadu. In other states a network of agents and dealers distributes post-larvae. The quality of these post-larvae is often less. Farmers are increasingly starting to use nurseries to enable post-larvae to acclimatize to local conditions before being released into larger grow-out ponds.

Shrimp are fed commercial feed. Farmers tend to use chemicals and probiotics to prevent disease outbreaks and to maximize yields.

Seasonality

Climates along the east and west coast vary widely, resulting in ranging cropping patterns. While Andrhra Pradesh and Tamil Nadu tend to have three crops a year (all year round). West Bengal, Orissa and also Gujarat have only one or two crops. In West-Bengal the stocking season is from mid February until mid September. The first harvest takes place from the end of May until August, the second from September to early December. In Orissa the first crop is stocked from January until March and harvested in April and May. The second crop is stocked from June until August and harvested from September until November.

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