Environment-friendly improved shrimp farming technology minimizes risks and increases production

Md. Ashraful Hoque

Technical Specialist

AIN Project, WorldFish-Bangladesh

Shrimp sector in Bangladesh play a vital role in respect of the country economy, more stable and diversified livelihood opportunities increase in income and food security to the adjacent people in the coastal areas of Bangladesh and it is the second highest foreign exchange earning source. The impact of the shrimp farming process has economic, social and environmental dimensions. All of these may have serious implications for sustainability, not only for shrimp farming but also for the rural community in the coastal areas of Bangladesh. Nevertheless, the shrimp sector in Bangladesh is facing several challenges, such as low farm yield, poor quality, WSSV incidence etc. are crucial issues hindering expected growth. Regardless of the high demand for this product, shrimp farming is still characterized as being traditional and having low productivity. In this situation, WorldFish- Bangladesh  taken  initiative activities and thought through the AIN project with the finance assistance of USAID for improving resource use effectiveness to boost productivity of shrimp farmers at farm level in a sustainable manner through dissemination of improved and bio-secured shrimp culture technologies namely Modified Traditional Technology (MTT). Training shrimp farmers, improved water management, low cost feeding and fertilization and better pond management, stocking Polymerase Chain Reaction (PCR) tested White Spot Syndrome Virus (WSSV) free post larvae (PL) are some of the features of the improved technology being followed the previous project to increase production effectiveness. This project suggested to stock screened shrimp PLs in gher farming those are come only from hatcheries which can be minimized the outbreak of Viral disease, less contamination and also be minimized the negative environmental impacts by  practicing the environment-friendly improved shrimp farming technologies and also focus on shrimp farming systems, their productivity, changing pattern of environmental issues and some extend on the socio-economic aspect of the adjacent dependent people in the coastal region of Bangladesh and assessing the potential for future improvements is considered essential for establishing an environment-friendly sustainable shrimp culture.

 

The Modified Traditional Technology is a modification of the Closed System Technology. In this system, virus free PLs are reared at relatively high density in the permanent nursery (10% of the grow-out pond) for up to 20-25 days, made in the grow-out pond. The nursery is cleaned, bio-secured and disinfected with bleaching powder at the dose of 60-70 ppm and fertilized with Urea and TSP. The PLs are fed with high quality commercial starter feed in the nursery and then released in the untreated grow-out ponds. This technology is favored for two matters. One is screened PLs are reared in the nursery for 20-25 days and another is as the virus attack usually starts at the age of 45 -60 days if the pond is not disinfected. As in the MTT system the PLs are released in the pond 20-25 days after nursing, it generally extend the days of disease occurrence up to 75-90 days. During this time most of the shrimp are attained to harvest weight and thus reducing the risk of disease outbreak.

Description and cost-benefit analysis on 100 decimal (water area) MTT gher farming system: Good pond preparation (remove pond bottom sludge) maintain stocking density, water quality parameters (water depth 4.5-5 feet, P^H7.5-8.5, alkalinity 80-120 ppm etc), proper feed  management, control algae and other management strategies are the key features of this technology which assist to minimize risk and  increase production. In this system the survival rate of PLs in nursery will be 80-85% and in grow-out pond juvenile survival rate will be 90-95%. For 100 decimal pond 6000 PLs will be stock in nursery pond and from that 4800-5000 Juvenile will be stock in grow-out pond in each cycle and per year up to 5 cycles will be possible to complete where during  harvesting period the average body weight of the shrimp will be 33-35 gm.

To implement this culture system the costs will be pond de-watering, pump out 2,000 taka, pond re-excavation, black soil removing, dike repairing labor 15,000 taka, lime for pond bottom soil 1,200 taka (Cao @ 1kg per decimal @ 12 taka per kg), fertilizers applied in pond bottom 570 taka (urea@ 100-200gm/decimal, TSP @ 100-200 gm/decimal, urea 16 taka/kg and TSP 22 taka/kg), mustard oil cake 320 taka ( oil cake 100 gms/decimal @ 32taka/kg), pond watering by pump 7,000 taka, lime in pond water 6,000 taka ( Cao @ 250 gm/decimal , @ 12 taka/kg 20 times for 5 cycles), fertilizer applied in pond water 17,100 taka (urea@ 100-200gm/decimal, TSP @ 100-200 gm/decimal, urea 16 taka/kg and TSP 22 taka/kg  30 times for 5 cycles), molasses in pond water 11,700 taka ( @ 100-200 gms/decimal, @ 32 taka/kg 30 times), oil cake 14,400 taka ( @150 gms/decimal for 30 times), rice-bran, yeast powder mixed 11,250 taka,  PCR tested PLs 15,000 taka ( 6000 PLs/cycle, @ 0.50 Taka/PL for 5 cycles), Feed 55,598 taka ( FCR 1:5, PL survival 80% in nursery and 90% in grow-out pond, ABW 33gms and feed @52 taka/kg) and when water salinity becomes less than 5 ppt then whitefish fingerling stocking cost 15,000 taka ( @ 10 pcs/decimal, average weight 125 gms/pcs, @ 120 taka/kg). Total costs will be 167,938 taka.

Production and return from shrimp 427,680 taka (712.8 kg shrimp @ 600 taka/kg, ABW 33 gms) and from whitefish 86,450 taka (665 kgs whitefish @ 130 taka/kg, ABW 700 gms, survival 95%). So, total income will be 514,130 taka and net profit will be 346,192 taka from the 100 decimal shrimp farming pond through MTT system.

Shrimp sector in Bangladesh play a vital role in respect of the country economy, more stable and diversified livelihood opportunities increase in income and food security to the small households and poor in rural coastal areas of Bangladesh is most important and it is the second highest foreign exchange earning source. In Bangladesh shrimp farming has negative ecological impact in terms of salinity increase, destroying marine species and also loss of bio-diversity. As an alternative of the negative impact on ecology, the economic importance of shrimp can’t be ignored for a developing country like Bangladesh. Proper management and planning can be provided a sustainable growth and advantage of shrimp farming as well as will be responded positive impact on environment. Pollution, destruction of sensible coastal habits, threats to aquatic bio-diversity and significant socio-economic cost must me balance against the direct economic benefits or earning from the shrimp farming. Finally the writer Md. Ashraful Hoque, Technical Specialist, AIN Project, WorldFish-Bangladesh mentioned that there is no way for boost productivities of shrimp without environment-friendly improved shrimp farming systems through which easily possible to produce double or more than double production of the national average production.