Shrimp farming is a burgeoning sector within the aquaculture industry, offering a lucrative opportunity for entrepreneurs and farmers alike. However, one of the significant challenges faced by shrimp farmers is managing undesired species in shrimp ponds. These undesirable species can disrupt the ecosystem, impact shrimp growth, and ultimately affect the profitability of the farm. This blog post delves into various effective methods for controlling these unwanted species, focusing on both physical and chemical approaches.

Unwanted species in shrimp farms can include crabs, snails, fish, jellyfish, turtles, small shrimps from creek water, and birds. Implementing biosecurity measures can substantially reduce the risk of disease outbreaks and the presence of these undesirable species, ensuring a healthier and more profitable shrimp farming operation.

We employ two primary methods for controlling undesirable species in shrimp ponds: physical and chemical. Physical methods involve barriers, traps, and manual removal to prevent and mitigate the presence of unwanted species. Chemical methods, by contrast, use specific treatments and agents to eradicate these pests without harming the shrimp.

Physical Method for Eradicating Unwanted Chemicals

1. Drying the Ponds

One of the most effective physical methods is drying the ponds. This method helps in eradicating pests and other undesirable organisms that cannot survive without water. Regular drying periods can significantly reduce the number of unwanted species in your shrimp pond.

2. Filter Mesh

Installing suitable screens at the inlet and outlet gates can effectively block the entry of unwanted species. These screens serve as barriers, permitting only the desired species to pass through, thereby ensuring a controlled environment within the pond. Types of filter mesh for creek water filtration:

• Synthetic Filter Mesh

1^st Filter – 20 MESH – 5 ft Length

2^nd Filter – 40 MESH – 8 ft Length

3^rd Filter – 60 MESH – 12 ft Length

 

• High-Quality Super Fine Nylon Filter Mesh

4^th Filter – 60 MESH – 20 ft Length

5^th Filter – 80 MESH – 20 ft Length

Precautions:

• The filters to be attached properly in cement colour with good quality ropes.
• While cleaning the filter mesh, the unfiltered water should not enter further. Even if egg of tiny shrimps and fish can be danger.
• There should be someone at the filtration point while pumping is going on. The ropes of the filter might be cut due to water force.

3. Proper Maintenance of Dikes and Water Gates

Regular maintenance of dikes and water gates is crucial to prevent leakage and the entry of burrowing organisms such as crabs and snakes. Ensuring that all barriers are intact will help keep your pond secure from these intruders.

4. Setting Up Traps and Bird-Scaring Devices

Using traps and bird-scaring devices can be an effective way to control predators. Strings of colored cloth stretched across the surface of the pond can scare away predatory birds, reducing the threat to your shrimp population.

5. Selective Harvesting and Cast Nets

During the culture period, you can resort to selective harvesting or the use of cast nets to minimize the impact of undesirable species. This method allows you to remove unwanted species manually without disturbing the entire ecosystem.

Chemical Method

1. Tea Seed Cake

Tea seed cake is an organic compound used to eradicate various unwanted species such as snails, jellyfish, and shellfish. This method should be applied after the culture period when the shrimp have been harvested. Tea seed cake is effective in eliminating these pests without causing long-term harm to the pond environment.

2. Chlorine Compounds

Chlorine compounds such as calcium hypochlorite can be used to disinfect shrimp ponds and eliminate unwanted organisms. This chemical should be applied after the culture period to ensure that it does not harm the shrimp. Proper dosing and thorough mixing in the pond water can help achieve effective results.

3. Rotenone

Rotenone, extracted from the roots of the Derris plant, has been used as a piscicide for centuries. It is a selective poison that affects finfishes but not shrimps at specific concentrations. Commercial rotenone is available in powder form, containing 4–5% rotenone. The effective dosage is 2 g/m3 for common predators and 8 g/m3 for eels. Fresh derris root is more effective than the dry one.

4. Saponin

Saponin is extracted from tea seed cake, a residue from the oil processing of Camellia seeds. It is widely used to eradicate finfishes without toxic effects on crustaceans, especially shrimps. The recommended levels of application are 12 g/m3 for salinities above 15 ppt and 20 g/m3 for salinities below 15 ppt.

5. Calcium Carbide

Calcium carbide can be used to control crabs by applying it directly into crab holes. When water is added, it activates the calcium carbide, killing the crabs.

6. Tobacco Dust

Nicotine, the active component in tobacco dust, is a non-selective poison. It is generally applied during pond preparation activities. A dosage of 200 kg/ha is effective in eliminating undesirable species, particularly snails. The pond should be flushed well before stocking to ensure no residual toxicity.

7. Ammonium Sulphate

Ammonium sulphate, a compound that also serves as a fertilizer, is effective when used with lime. The toxicant, ammonia, is released from the reaction of ammonium sulphate with lime. This chemical is applied during pond preparation at a dosage of 1 part ammonium sulphate to 5 parts lime.

 

Eradication of unwanted animals from the pond prior to stocking

Below are the eradicating agents and the dosage/application of these agents. These methods ensure effective control of unwanted species in shrimp ponds.

 

Sl No	Eradication agent	Advisory on dosage
1.	Tea seed cake	216Kg/ha tea seed cake+144Kg quicklime Soak in warm equal quantity water over night, add quicklime prior to administration
2.	Tea seed powder	100-200ppm
3.	Mahua oil cake	200-250ppm Soak in warm equal quantity water over night and administer
4.	Lime+Ammonium sulphate	1 part of ammonium sulphate and 5 parts of lime. For 1 hectare pond with 10cm water depth add 5Kg ammonium sulphate and 25 Kg lime. Lime must be added first to raise the pH above 8 and add ammonium sulphate
5.	Sodiumpentachlorophenate PCP-Na)	0.5ppm
6.	Mode of application Calculation of dosage in ppm Length (m) of water in the pond- Width (m) of water in the pond- Depth (m) of water in the pond- Calculate Volume in litres- (length * width*depth *1000)	Determine the quantity of water (in case dosage is calculated in ppm) by multiplying length x width x depth in metre which gives cubic meter water, and on multiplying with 1000 gives the volume in litres. 1ppm = 1mg per litre. If the application is per hectare the calculation must be based on the area (1 hectare = Approximately 10,000.0 square meter).

 

Conclusion

Managing undesirable species in shrimp ponds is crucial for maintaining a healthy and productive aquaculture environment. Both physical and chemical methods offer effective solutions, each with its benefits and limitations. By implementing these strategies, shrimp farmers can optimize their pond conditions, ensuring high-quality shrimp production and maximizing profitability.

At Aquabeats, we are committed to empowering shrimp farmers through innovative technology and expert guidance. Our Aquaman App, Aquabeats Labs, and Aquabeats Academy provide comprehensive support for all aspects of shrimp farming, from data management to workforce training. Join our partnership program today and take your shrimp farming to the next level.

For more information on how we can help you achieve sustainable and profitable shrimp farming, contact us at [email protected]. You may also check more information at our website www.aquabeats.in. Let's revolutionize the aquaculture industry together!