Pond preparation and management for Successful shrimp farming

Pond management means balancing production (anabolism) and decomposition (catabolism) processes. The aquatic environment provides food, space, shelter, and oxygen and it receives metabolites (faeces, ammonia gill excretion, CO2, etc.) from the farmed organisms, phytoplankton, zooplankton, benthos, and other microbial communities. Decomposing faeces consumes oxygen, while ammonia and nitrite, which are potentially toxic, are released.      

Best management practices (BMPs) for shrimp farming are a standardized set of farming practices to ensure the environmental and financial sustainability of shrimp farming systems. India is one of the leading shrimp exporting country, producing more than 0.7 million tonnes of farmed shrimp.  

What are BMPs?

Best management practices (BMPs) for shrimp farming are a standardized set of farming practices to ensure the environmental and financial sustainability of shrimp farming systems. It includes the following key points:

1. Pond preparation methods
2. Water quality
3. Removal of organic wastages from pond bottom
4. Fertilization of the pond
5. Biosecurity systems
6. Seed selection
7. Stocking methods
8. Feed management
9. Disease management
10. Harvest methods 

1. Pond preparation methods:

Following best management practices of pond preparation provides a cleaner environment for shrimp cultivation by adopting scientific methods to reduce the risk of diseases and other outbreaks.  The following should be practiced while preparing ponds:

1. Maintain min water level 1.4 mt to maintain water holding capacity.
2. Disinfection before stocking with a powerful disinfectant helps to control microbial load of ponds.
3. Sludge management is equally important esp. in cases where the gap between two cultures is less. Sludge is a buildup of organic materials that accumulate in pond, mixes with inorganic materials.  It causes algal bloom and growth of pathogens.
4. Use a powerful probiotic before and post stocking to control growth of harmful bacteria in ponds and also support shrimp health.
5. Managing mineral balance in ponds is important to ensure that the mineral requirements of shrimp are met 

2. Water quality

Water quality is the most important element to achieve a successful crop. The entire culture is dependent on this aspect and to maintain a good water quality, we must adopt following methods.

1. Maintain reservoir for water treatment.
2. Use double layered 60 mesh to avoid unwanted carriers and use 80 mesh below the inlet.
3. Use good quality bleaching powder (35% or 70%) for treatment, do not use any pesticide and insecticide.
4. Use triple salt compounds like AquaCare 3D to avoid pathogens in water.
5. To maintain healthy plankton bloom, apply fermented juices with yeast and apply good quality probiotics like AquaCare Control.
6. Chain dragging is also recommended when healthy bloom has not happened.
7. Use good quality minerals to maintain ionic balance in the water system especially calcium, magnesium, and potassium like AquaCare Mineral Balance. 

3. Removal of organic waste from pond bottom

Organic matter releases toxic gases like ammonia and hydrogen sulphide in the pond leading to stress or death of shrimps. Organic waste is in the form of layer on the soil with black colour found in feeding area, corners, trenches and in the centre in ponds. Aerators should be checked for the presence of black layer when it is in wet condition. For removal of organic matter, following methods can be utilised:

1. Use Nitrosomonas and Nitrobacter probiotics along with Photo-synthetic bacteria like Rhodocooccus and Rhodobacter to remove nitrates and hydrogen sulphides.
2. Drying and ploughing of the pond enables oxidizing the organic matter and reducing the sludge.
3. Plough the soil for removal toxic gases and removal of gastropods and other unwanted debris.
4. To remove unwanted species apply good quality of teased cake around 40kg per acre. 

4. Fertilization of the pond

Fertilization of the pond helps to balance the mineral content of the pond and increases pond carrying capacity as well as soil fertility.  It can be achieved through:

1. Maintaining organic matter content at min. 1.5% - apply 500kg to 1000kg vermicompost or potassium humate at 80 kg per acre.
2. Apply good quality lime to maintain optimal pH of the soil.
3. Apply chelated zinc 6kg per acre.
4. For EHP infected ponds, use concentrated bleaching powder 100kg Potassium permanganate 6kg , Formalin 6 lt, Copper sulphate 6kg , Calcium oxide 800kg in water per acre;  thoroughly mix and keep water for 6 days then drain out again and dry.

5. Biosecurity

Biosecurity in shrimp farming involves stocking disease free seed, pond preparation, water screening, prevention of entry of disease carriers, personal hygiene, and sanitation. Biosecurity plays a pivotal role in farming to maintain disease free environment.

1. To control carriers (Burrowing) use crab fencing with good quality nylon & lDPE materials.
2. Use bird fencing to avoid birds and its droppings preferably red and blue coloured threads.
3. Farming area should be clean and maintain sanitization dip at entry and exit areas.
4. Clean farm equipment and utensils regularly with potassium permanganate or any hypochlorite solutions to avoid cross contamination.
5. Maintain personal hygiene of the farm workers.

6. Seed selection & stocking methods

Selection of the seed is the one of the most important factors on which the entire crop depends.

• Select seed from CAA certified hatchery with SPF bloodstock and PCR tested.
• Before selecting the seed check your pond water conditions according to your salinity and do stress test in the hatchery with your pond water inputs.
• Avoid wild seed and contaminated, unhealthy seeds.
• Seed should be packed with sufficient aeration and good quantity artemia for longer transport.
• Select good PL size (PL 15 to 20) is ideal.
• Seed stocking should be done in early mornings or late evenings.
• Before stocking maintain acclimatization process. 

7. Feed management

Feed management is important for successful shrimp production and costs 50-60% of the total operational cost.

1. Monodon requires higher protein, omega-3, phospholipids and phosporus. A good quality feed like Gamma (for Vannamei) and Kuroline (for Monodon) which is specifically formulated to meet the requirements of species should be given.
2. The feed should not be more than 120 days from date of manufacture.
3. Follow feed chart as per your shrimp body size and weight to avoid wastage.
4. Reduce feeding by checking in check tray feeding.
5. Reduce feed in rainy and cloudy weather conditions as well as plankton crash and high temperatures.
6. Reduce feed in pre moulting and low DO conditions.
7. Regularly monitor ammonia and nitrate conditions.
8. Do regular sampling in every week to determine the growth, survival, and FCR.
9. Do not feed excess as it leads to pond water quality deterioration.
10. Feed should be stored in cleaned and good ventilated areas avoiding direct sunlight and keep feed in pallets and rodent free environment. 

8. Disease management

Check the health of shrimp in feed check trays on daily basis. If there is poor feed consumption for consecutive three to four days, it indicates health problems. Check the general health and growth of shrimp collected by cast net on weekly basis. Carry out sampling during early morning or late evening at different places.

• Regularly check bacterial loads and water quality parameters.
• Identify fouling and deformities.
• Gut should be 80% filled with feed.
• Observe antenna cuts and hepatopancreas colour.
• During virus outbreaks sanitize with good sanitizers and use good probiotics on regular basis.
• Avoid cross contamination by adopting hygienic methods.
• Dead and affected shrimp should be buried outside the pond area.
• Don’t move equipment from affected ponds to unaffected ponds. 

9. Post Harvest and Harvest methods

For freshness and quality of the shrimp, harvest methods are important:

1. Exchange 30% water before one week
2. Apply soil probiotics to avoid gill infections.
3. Apply oxidizers like Hydrogen peroxide or potassium permanganate to avoid black colouration.
4. Avoid harvesting in moulting period.
5. Don’t feed before 6 hrs of harvesting.
6. Complete the harvest process in mornings to avoid discolouration.
7. After harvest apply lime and bleaching in the harvest area to avoid cross contamination.
8. Packing should be done with good quality ice. 

For further information, kindly write to us at contact.india@skretting.com or visit our website: www.skretting.in