DISEASE PREVENTION AND HEALTH MANAGEMENT IN COASTAL SHRIMP CULTURE

The consultant would like to thank all those who assisted in the implementation of this consultancy mission. In particular, the efforts of Mr. Masudur Rahman (NPD) , Dr. Nitya Nanda Das (DFO/ Cox's Bazaar), Mr. Rizaul Karim (DFO/ Khulna),Mr. Swapon Kumar Dev (DFO/Bagerhat), Mr. Habibur Rahman (DFO/ Satkhira) , Mr. H. Konuma (FAOR/Bangladesh) and Dr. Shah (FAOR - Office) are greatly appreciated.

The enthusiasm of all those involved in the implementation of this project is commendable , and gives great hope for its future potential.

As always, FAO/RAP has been helpful in numerous ways - special thanks to Ms. Dora Blessich and Khun Arunee.

1.0 INTRODUCTION

Seasonality in the climate, including cold and warm months and the vast river delta of Bangladesh, provide an opportunity for diversification of shrimp culture. There is a lack of technical knowledge in the management of shrimp farming and increasingly more areas are being developed into shrimp farms without proper scientific assessment. It has been claimed that the Bangladesh shrimp farming industry has suffered severe problems over the past three to four years due to disease outbreaks, mainly SEMBV. According to the Department of Fisheries (DOF), Bangladesh suffered a 44.3% production loss in 1996, leading to a reduction in foreign income of 42.3% from exporting shrimp cultured in coastal areas. Therefore there is an urgent need to address the production related problems in the present shrimp farming industry in Bangladesh.

The consultant is scheduled to carry out two missions to Bangladesh with a total duration of four months and two weeks in his own country to prepare training material. In close collaboration with National Counterparts (NCPs) and under the direct supervision of a National Project Director (NPD), the consultant will review the production and health management related problems in the coastal shrimp culture in Bangladesh and develop a strategy for extension to train farmers. The specific Terms of Reference (TOR) for the first mission of two and a half months were proposed as follows:

1. Review the problems related to production and health management in coastal shrimp culture in Bangladesh.

4. Assist the consultant on health management to conduct two, 3-day workshops for DOF field officers on health management.

The first mission was arranged to coincide with visits by the FAO/FIRI backstopping officer and the project's International Consultant. The NPD would be the Director (Marine) of the Department of Fisheries (DOF) of Bangladesh. Considering the major share of the extensive and traditional farming systems to the national shrimp production, and appreciating the importance of traditional shrimp culture to the rural farming community, it was decided in consultation with the FAO/FIR health specialist and the NPD that the present consultancy would concentrate mainly on traditional and extensive shrimp farming systems.

2.0 AN OVERVIEW OF THE COASTAL SHRIMP CULTURE IN BANGLADESH

The total fish production in Bangladesh in 1996 was 1.264 million MT, contributing 5% in GDP and 16.67% in the gross value of agricultural products. Total export earnings from the fisheries sector amounted to 13,400 million TK in 1996 of which 11,000 million TK came from shrimp. The shrimp industry has gained an important place in the national economy and is the third highest foreign income earner. It has been estimated that more than 380,000 people are directly or indirectly involved in the shrimp culture industry. This industry provides direct employment opportunities to some 350,000 people and employment to approximately 25,000 - 30,000 people involved in provision of equipment, lime, fertilizer and feed suppliers and infrastructure developers. In addition to shrimp culturists, direct employment opportunities include shrimp fry collectors, nursery operators, fry transportors and depot operators who have the shrimps deheaded before sending them to the processor. With the development of proper management techniques for further expansion in the shrimp farming industry, employment opportunities in this sector should increase greatly.

2.1 Resource Availability

Bangladesh is known as the land of rivers. Its inland water resources include estuaries, rivers and canals, ponds, tanks, natural depressions, lakes, low-lying paddy fields and flood plains. The extent of estuaries, rivers and canals in coastal areas amounts to 10,315.63 ha. In addition to this it has been estimated that there are about 2.5 million ha of tidal lands in the coastal areas including low-lying areas, paddy fields and polders. Out of this vast coastal land area, 134,560 ha have been developed into 13,148 farms to culture Peneaus monodon (the Black Tiger prawn) popularly known as Bagda in Bangladesh. To date, a systematic survey, however, has not been carried out to identify suitable areas for shrimp farming in Bangladesh.

In 1994, the Ministry of Fisheries and Livestock compiled a report on the site selection of Bagda shrimp hatchery zones and semi-intensive Bagda farming areas. According to this site selection report 13,610 ha of coastal land was identified for the development of a semi-intensive type of Bagda culture.

This site selection report does not include areas suitable for traditional or improved extensive type of culture of Bagda as this aspect was not included in the TOR. These two types of culture practice, however, are currently contributing more than 95% in terms of both area under culture and production to the Bagda farming industry in Bangladesh.

The areas identified suitable for a semi-intensive type of farming given in the report prepared by the Ministry have not been evaluated on a point-scoring system for their environmental compatibility. Therefore one has to do a more careful evaluation of these areas to assess their environmental compatibility for a semi-intensive type of Bagda culture before development.

2.2 Resource Allocation and Utilization

The Bagda culture in Bangladesh is mainly confined to two Divisions in the country, namely, Khulna and Chittagong. Khulna Division has 8,104 Bagda farms covering an area of 99,918.70 ha while Chittagong Division has 2,128 farms utilizing 29,771.00 ha of coastal land area. Of the seven districts in Khulna Division Bagda farming is confined to three districts, namely, Khulna, Satkhira and Bagerhat. Of the five districts in the Chittagong Division Bagda farming has taken place in Cox's Bazaar, Chittagong and Noakhali.

The allocation of state owned lands (khas lands) for Bagda farming initiated in 1977 with leasing 228 ha of coastal land from the Chokoria mangrove reserve, popularly known as the Chokoria Sundarbans, in the Chittagong District of the Chittagong Division. Up to 1985 a total area of 3,077 ha was leased to the private sector from Chokoria Sundarbans for shrimp culture until the Ministry of Land Revenue and Land Administration issued an instruction (No. 8-400/85/1232 (2) dated 8 December 1985) to the effect that all khas lands and lands suitable for shrimp culture but under the administrative control of other ministries are deemed to have been reverted to the Ministry of Land Revenue and Land Administration for the purpose of leasing the land for shrimp culture. The lease term is initially 10 years with a provision for further extension. In the Chokoria Sunderban area, 1,695 ha and 694 ha have been developed into shrimp culture farms sponsored respectively by the International Development Agency (IDA) and the Asian Development Bank (ADB). No attempt has been made for a technical evaluation of these lands for their suitability and environmental compatibility for Bagda farming prior to leasing or prior to development.

In addition to the utilization of Sunderban areas the Bangladesh Water Development Board (Polders) has also been utilized to set up Bagda farms. A licensing system has been adopted by the Divisional Administration in order to obtain salt water through the polder dike by establishing water control gates. This licensing system mainly focuses on the design of the water control gates and the selection of farmers and not on the suitability and environmental compatibility of the proposed area for Bagda farming.

Thus Bagda farming is being mainly carried out in Sunderban and Polder lands and is facing technical difficulties.

2.3 Seed Resources

The present Bagda culture industry in Bangladesh demands an annual supply of 3,000 million post-larvae (PL) to be stocked in production systems. According to an estimate made by the DOF and the Fisheries Research Institute (FRI) the annual Bagda PL collection from the wild is around 2,000 million. Main fry collecting grounds are located in Cox's Bazaar District which provides more than 70% of the total PL collection. This industry has provided employment to 117,835 people living in the coastal areas of the shrimp farming districts. This is equivalent to 17,000 PL/collector/annum.

Bagda fry are available annually during two peak seasons. The high peak is in March to May and the low peak is in September to November. Fry are collected for 4 to 5 days around every full moon and new moon. This provides a 10-day period of fry collection for each month during the peak season. Assuming an average of 150 Bagda PL/collector/collecting day for a duration of around six months, the realistic number of PL/collector/annum would be around 9,000, generating an income of 2,700 to 4,500 TK/annum/collector. Thus the amount harvestable from the wild would be around 1,060 million PL/annum. The Bagda hatcheries in the country contribute only 10-15 million Bagda PL, bringing the total supply to 1,075 million. If the water area under culture is 90% (excluding dikes) of the total area developed into Bagda farms, the area available for stocking would be 121,039 ha (90% of the total area of 134,488 ha). At a stocking rate of one PL M^-2, the shortage of PL supply would be around 150 million. An increase of the Bagda stocking rate with improved pond management is difficult due to the shortage of PL supply. Thus the Bagda farming industry in Bangladesh is very much in short supply of PL to stock in production system.

It is very much uncertain whether the shortage in PL could be met by an increase in the harvesting effort from the wild as no estimated resource potential of wild Bagda is available. Therefore intensifying the stocking rate is not advisable without taking proper measures to overcome the PL shortage.

2.3.1 Hatchery Bred PL to Meet the Short Supply

At present the hatchery bred Bagda PL are produced from 11 hatcheries of which only one is owned by the state. According to the survey carried out by the DOF a land area of 131 ha has been identified in Cox's Bazaar District in the Chittagong Division to accommodate 198 hatcheries. The expected output from the 198 hatcheries was not stated.

The recommended areas in Cox's Bazaar for hatchery production should be reassessed on scientific data as most of the critical scientific data were not available at the time of the survey. It should be noted that if the hatcheries are not located at suitable sites and continue to fail in operation, this may lead to an increase in the harvesting pressure on the wild PL resources.

The demand for 3,000 million PL has been derived assuming a stocking rate of 2.5 PLs M^-2. To achieve the 3,000 million PL from the present supply (1,075 million PLs) an increase of 1,925 million PL is necessary. Thus the proposed 198 hatcheries should have an average production capacity of around 10 million PL/annum.

Due to the cold weather that prevails during December to February which could lower the water temperature to as low as 12⁰C and monsoonal rains that prevail during June to August which could lower the salinity below the desired level for hatchery operation, the production of hatchery-bred PL would be limited to three - four months/year. To continue PL production throughout the year, the desired conditions have to be maintained in the hatcheries by heating and adding salt or using reconstituted salt water. All these activities would incur an increase in the operating cost resulting in a high PL price. With these operational limitations, to produce an average of 10 million PLs/hatchery/annum would be a difficult task.

An increase in the number of Bagda hatcheries to meet the short supply would be a difficult task for economic feasibility reasons. One way of keeping the hatchery operating throughout the year is to produce Bagda PL during the first three months to coincide with the major Bagda stocking season (February to March) in ponds in alternation with producing fresh water prawn (Golda) PL from April to July to coincide with the rainy season (commencing from June) for stocking. In order to achieve this, equal emphasis should be placed on the development of both Bagda and Golda culture in Bangladesh.

With the limitations in Bagda hatchery operation and the socio-economic importance of the wild PL collection industry, it is more likely that the Bagda farming industry will depend largely on the wild resources for PL requirement. It is therefore urgent to monitor this resource closely for sustainable utilization.

2.4 Shrimp Production

Bangladesh contributes around 5% to the total global cultured shrimp production. The total marine and brackish water shrimp production in 1994-1995 was 53,948 MT of which 30,503 MT came from the coastal aquaculture. Cultured shrimp production contributes around 2.54% to the total fish production in 1995. Shrimp exported in 1995 amounted to 26,277 MT, generating 10,456.7 million TK as foreign income which is 10.36% of the total national export earnings. This percentage has dropped to 6.32%.

The production loss in cultured shrimp due to disease and health management problems during the 1994 - 1997 period, as claimed by the government sector as well as by the shrimp culture industry, is not reflected in the quantity exported. The reason may be that the quantity exported consisted of shrimp from both captured and cultured industries. The drop in the percentage increase in terms of value may reflect the losses in Bagda production (since it is the highest valued shrimp in the export market) and the increase in other small shrimp production in ponds, if the export market price for shrimps was more or less uniform during this period.

In a culture pond, 50-60% consists of Bagda. Other species contributing to the composition are small shrimp 15-25%, Metapeneaus monoceros (Horina) 15-18%, Peneaus indicus (Chaka) 1-6% and Macrobracium rosenbergii (Golda) 0.2-5%.

The high percentage of non targeted shrimp species indicates a potential risk for SEMBV disease outbreaks as many crustaceans are known to be carriers of SEMBV.

Improved extensive farms have experienced productivity levels ranging from 20 to 180 kg per acre. The productivity of semi-intensive farms varied from 0.5 to 5 MT per acre. The productivity levels recorded during this mission could be considered as low for an improved extensive system, indicating that proper improvement is needed.

2.5 Farming Systems

According to the terminology used for Bagda farming systems in Bangladesh, three different types of culture systems are practiced in the four coastal districts where Bagda farming has been developed. These are known as traditional or extensive, improved extensive and semi-intensive culture systems. Of the total area of 134,488 ha under Bagda farming only 996 ha have been developed into semi-intensive farming. Thus the main focus in this consultancy is on traditional and improved extensive types of culture. Of the developed area for semi-intensive farming, 80% is in Cox's Bazaar District and the rest in Khulna and Satkhira Districts. In contrast, 77% of the area developed for traditional and improved extensive types of culture lies in Khulna, Satkhira and Bagerhat Districts, with the balance of 23% in Cox's Bazaar Districts.

An extensive system operates with minimal inputs. It depends on the tidal amplitude of the water resources for the intake and discharge of water. Some farmers who practice an extensive type of culture depend on the shrimp PL and fish fry that come with the tide for stocking while the others stock shrimp PL collected from the wild (known as the natural post-larvae) or bred in hatcheries. Traditional systems utilize areas ranging from 10 ha to 200 ha as one single pond. These ponds are shallow with an average water depth of 60 cm and an irregular bottom morphometry, irregular in shape, and use a single canal for the supply of water to the system as well as drainage discharged water from the system. No proper screens are employed at the inlet and outlet which allow the entry of predatory fish from both the inlet and outlet into the pond with the rising tide. Farmers seem to be ignorant of the significance of production loss due to predation. Some traditional systems employ one or more nursery compartments and a catching compartment within the pond. The nursery compartment, which varies from 0.5% to 20% of the total pond area, has no gate connection with the grow-out pond. The connection is made by cutting a part of the nursery dike at the time of releasing the fry. This improved extensive system is basically similar to the traditional system, except for the use of certain inputs during the culture practice such as lime, fertilizers and feed. Improved extensive systems in some areas in Satkhira District use mechanical pumps to fill the ponds with water.

A semi-intensive system operates with higher inputs than those of traditional or improved extensive systems. Some semi-intensive systems depend on the tidal amplitude for water intake into the ponds while others use mechanical pumps to pump water into the ponds. They use natural post-larvae or hatchery bred PL, or both types, for stocking in the ponds. Ponds are square or rectangular in shape with a more or less even bottom morphometry sloping gently towards the outlet from the inlet. Pond sizes vary from 0.5 ha to 2 ha. Some semi-extensive systems employ separate inlet and outlet canals while others use one inlet canal and discharge water from individual ponds directly into the water source.

2.6 Culture Practice

The culture practice observed in traditional and improved extensive systems is multi-stock and multi-species culture of shrimp and fish (Bagda as the target species), while the semi-intensive systems practice monostock monoculture of Bagda. Strictly speaking one has to deal with problems in a polyculture system, since traditional and improved extensive systems in Bangladesh are not Bagda monoculture systems. Hence, the term Bagda culture in traditional and improved extensive systems used in this report should mean shrimp/fish polyculture systems. This Bagda culture is practiced in alternation with/or without crops. When Bagda culture is practiced in alternation with paddy it is carried out from February to July and paddy from August to December. This type of alternation is practiced in the southwestern zone of Bangladesh, i.e. in Satkhira, Khulna and Bagerhat Districts. Bagda culture alternating with salt production is practiced in the southeastern zone, i.e. in Cox's Bazaar District. Salt production is carried out from December to April followed by Bagda culture from May to November, which is the wet season. Bagda culture alternation with salt has shown frequent production losses and problems relating to health management as the Bagda culture is confined to rainy season.

Seed supply - Irrespective of the culture system practiced, seed requirement is fulfilled by the natural post-larvae or by the hatchery bred PL. As 95% of the post-larval requirement is met by natural post-larvae, collecting and post-collecting methodologies have a great influence on the health management of the culture system. An important concern is the weakness in the procedures of collecting, sorting and holding of natural post larvae. Post-larvae are collected during rising tide in day time by means of push nets and set-bag nets. The PL caught in the nets are transferred into aluminium pots or basins containing water for sorting. The water used for holding PL during sorting contains dirt and silt. Despite guidelines given to PL collectors to use a shelter to provide shade for sorting, this is done under direct exposure to the sun. Sorted Bagda PL are held in aluminium pots containing silty water in high densities and without aeration (up to 350 PL/litre). The collecting and sorting procedure takes about four to six hours, causing stress to the PL.

The sorted PL are transported directly to the farmer or held in nurseries until transportation. In many nurseries operators hold PL in shallow cement cubicles containing 100 litres of water each. The water is mostly silty and stocking densities are high. To change the water, PL are transferred into another cubicle using a hand net. Without any doubt such an operation is stressful to the PL before reaching the farmer for stocking. Nursery operators have experienced up to 90% mortality when holding the PL for a few days. In many instances the time taken for PL to reach the farmer exceeds 24 hours.

Pond preparation - Pond preparation prior to stocking is being done only in improved extensive and semi-intensive culture operations. Some farmers dry and scrape or plough the bottom before liming. Those who cannot dry their pond bottom, scrape the topsoil layer or plough. Fertilization is done after filling the pond with water. The most widely used lime is calcium oxide. Fertilization is done either with inorganic fertilizers (urea and tri-super phosphate-TSP) or in combination with organic fertilizers (cow-dung). In addition to liming and fertilization, mustered oil cake is used to disinfect the ponds.

Some semi-intensive farmers use chlorine to disinfect water in the reservoir. No semi-intensive farm is designed to re-use treated water by employing sedimentation, oxidation, biofiltration and treatment tanks.

Stocking - Farmers who practice traditional or improved extensive method of culture, stock PL into a nursery compartment or directly into the pond. The PL are held in the nursery for 30 to 45 days before releasing them into the grow-out pond. A few farmers operate a nursery compartment within the pond to correct the salinity by adding table salt to acclimatize the PL.

Most farmers stock PLs without proper acclimatization and do not know the significance of proper maintenance of a nursery compartment. The present practice of preparation and maintenance of the nursery compartment does not provide a healthy environment for the PL as they are already stressed due to collection, sorting and holding procedures (see Health Management Consultant's Report - TCP/BGD/6714 Field Document No. 1 for proper preparation and maintenance of a nursery compartment in a Bagda grow-out in Bangladesh).

Stocking densities employed in extensive and improved extensive methods of culture vary from 0.5 to 8 PLs M^-2. This stocking density excludes other shrimp and fish that enter with inflowing water. Therefore the actual stocking density may be more than the density farmer quotes. As a consequence, when formulating pond management practices to suit Bangladesh conditions, a realistic stocking density in a Bagda pond has to be made. This could be achieved by using as a guide the percentage species composition in Bagda ponds, given in section 2.4. Moreover farmers do not have any idea of the age of PL at stocking. Probably the natural PL that a farmer stocks are of mixed ages leading to size disparity.

Repeated stocking is done from January to April and from September to December in extensive and improved extensive systems, irrespective of the conditions of pond environment. Semi-intensive systems stock twice a year, first in February to March and second in August to September. They employ a stocking density of 15 to 50 PL M^-2.

Water exchange regimes - Many farms that practice traditional and improved extensive method of culture do not exchange water frequently. They exchange water fortnightly, i.e. on full-moon and new-moon days. The farmers do not know or do not make any attempt to estimate the percentage of water that they change at a time, indicating a lack of knowledge on water management.

In some areas (in Bagerhart District) farmers employ zero water exchange strategy, since there is no way for water intake and discharge without crossing the neighboring farmer's pond.

Semi-intensive farmers change 20% to 50% of the pond water regularly. Water exchange is done by lowering the water to the desired level, and by draining and refilling to the original level.

Water quality - Traditional and improved extensive farmers do not measure any water quality parameter. By experience and due to the pattern of rainfall, the farmer knows that salinity decreases towards June to July to 0 ppt where it remains close to fresh until it starts rising from October. Many semi-intensive farms monitor the basic water quality parameters such as pH, salinity and temperature. Salinity of the water does not rise to a level requiring fresh water for dilution.

Feed and feeding - Among farmers who practice improved extensive methods of culture, a few feed their Bagda in ponds. Commonly used ingredients in the feeds are rice bran, wheat bran, fish meal and potato. The feeding regimes are selected arbitrarily. There is no method to assess whether ponds are overfed. No estimation of survival rates is done to adjust the feeding regime. Thus the farmer lacks knowledge on whether he is under- or over-feeding Bagda. Feed is placed in trays or cast by hand over the entire pond area.

Semi-intensive farms use high-quality formulated commercial feeds. Feeding is done four to five times a day in the shallow areas of the pond by employing feeding trays. Survival of shrimp is estimated by cast netting the pond or counting the shrimp in feeding trays, and feeding rates modified accordingly.

Aeration - Aeration is done only in semi-intensive farming systems. They employ 2 to 8 short armed paddle wheel aerators with a 1 to 2 HP per acre pond.

2.7 Disease Situation in Bangladesh Shrimp Culture

Mass mortality due to disease in the shrimp farming industry was not reported until 1994 when the industry suffered severely from SEMBV disease outbreak. Since then disease outbreaks occur repeatedly in all three types of farming systems.

Prior to this disease outbreak, the Bangladesh shrimp farming industry observed the following disease conditions:

Significant mortality was observed during the rainy season (June to August) due to sudden drop in salinity and temperature.

The SEMBV disease first occurred in 1994 only in semi-intensive shrimp farms operating in Cox's Bazaar District. Nearly all semi-intensive farms are not operating at present due to repeated infection of SEMBV over the period 1994 to 1996. It is widely believed that this disease was introduced into Bangladesh with the importation of PL from Thailand and Taiwan. It is known that SEMBV can be present in PL and that this can be a significant route of infection of the disease to shrimp grow-out ponds. The health status of the brood stock used in shrimp hatcheries or natural PL used in Bangladesh is currently not known. It is interesting to note that SEMBV disease was not observed in traditional and improved extensive systems until 1996, despite the occurrence of this disease in semi-intensive Bagda farming systems in 1994 in Cox's Bazaar District. Even though the first infection started in Cox's Bazaar, a heavy infection of SEMBV was first observed in Satkhira and Khulna Districts in traditional and improved extensive systems; their coastal areas border the eastern coastal area of India where Bagda farming was heavily infected with SEMBV since 1994. As the Bagda industry collapsed in India during this very period it is not to be excluded that PL were marketed over to Khulna and Satkhira Districts from India. These Indian PL may have been sold as natural PL in Bangladesh. This may have been the principal route of infection of SEMBV in 1996 into Khulna and Satkhira. The importation of PL should be discouraged to prevent possible repeated infections. The most effective way of doing this is to raise the farmers' awareness through repeated information programmes.

Other principal routes of infection can occur at different stages of the culture cycle through carriers. Pure monoculture of Bagda does not exist in traditional and improved extensive systems in Bangladesh because of the inevitable intrusion and sometimes deliberate stocking of other shrimps and crab species. Many of these shrimp and crab species are known to be carriers of SEMBV. Thus the traditional and improved extensive Bagda farming systems are open to all possible routes of SEMBV infection.

According to the statistics shown above, it is believed that there is a decreasing trend in the number of farms affected and production losses due to SEMBV. Since the number of farms given was the same for both 1996 and 1997, it appears that reference is made to farms established in the respective districts and not those in operation. Moreover the affected farms do not specify the type of disease. It is therefore difficult to establish a decreasing trend in the SEMBV infection in the Bagda farming industry in Bangladesh; and it is important to know the types and magnitude of diseases that occur due to development management strategies.

District Number of farms^*Number affected Area affected (up to May) as a percentage

District Targeted production Production lost Value of lost production (MT) (MT) (million TK)

According to the Shrimp Cell of the DOF, in 1996, 13,284 MT of cultured shrimp, valued at 4,688 million TK, were lost due to disease. This amounts to a loss of 42.3% when compared to foreign income from export of cultured shrimp in 1995.

During this consultancy mission, it was observed that it is not only SEMBV disease which causes mortality in these systems at present. Vibrio infections also appear to be a significant contributory factor to the recurrent mortalities. Red discoloration in Bagda was observed in almost all areas where Bagda farming is carried out in Bangladesh. Mortality usually occurred a few days after red discoloration after 60 to 70 days of post-stocking. Red coloration and vibriosis are defined as stress-related diseases in shrimp. According to the consultant's observations, deterioration of the pond environment plays a key role in stressed shrimp, leading to later infections. This may be caused by spoiled pond bottoms containing black soil and by poor quality Natural PL, caused by stress during collection and handling methods which may have cause this infection. Same conditions may have favored the repeated occurrence of SEMBV infection. It is of vital importance to determine the type and magnitude of the prevailing diseases in Bagda farming in Bangladesh for effective mitigatory measures to be implemented.

The following measures have been practiced by the farmers to control or prevent disease out breaks in Bagda farming.

Pond bottom drying and application of lime and calcium hypochlorite before the introduction of water.

Use of chemotherapeutants such as copper sulfate (0.5 to 1.0 ppm), malachite green (1.0 ppm), potassium permanganate (0.5 ppm) and formalin (5.0 to 10 ppm).

The use of anti biotics and chemotherapeutants, without proper understanding of their efficacy, should be discouraged. Formalin at a rate of 70 ppm has been used elsewhere as a disinfectant to prevent transmission of SEMBV by water. The application of formalin could cause a drop in dissolved oxygen, affect the plankton bloom and not kill the carriers.

During this consultancy mission, the following trends were observed in disease outbreaks in extensive and improved extensive Bagda farming systems in Bangladesh.

Diseases are more likely to occur when PLs are stocked during cold months (December to January).

Diseases are more likely to occur when PLs are stocked close to the rainy season or during the rainy season (May to August).

Farmers often claim that mortality of Bagda is due to disease. This statement includes situations where yield from a pond is below expectation. Diseases can be due to either an infectious agent or to poor environment or both. The observed trends in disease outbreaks during this mission indicate that production losses are mainly due to poor environmental conditions, causing stress in Bagda (see TCP/BGD/6714 Field Document No. 1 by the International Consultant on shrimp health management for a comprehensive account on the shrimp disease situation in Bangladesh).

Therefore, to develop an extension strategy to address the problems relating to production and health management, it is vital to first identify the factors that make the pond environment sub-optimal and the cause of stress in Bagda, making them susceptible to diseases. Such causes can be subsequently prioritized to determine whether they could be corrected with low-tech and at low-cost, making a significant improvement in the PL quality and pond environment.

3.0 EXTENSION STRATEGY

During the mission the consultant visited each Thana of each Bagda farming district (Cox's Bazaar, Bagerhat, Satkhira and Khulna) in order to identify problems relating to production and health management. In each district, the consultant had discussions with District Fisheries Officers, Thana Fisheries Officers, Assistant Thana Fisheries Officers, Extension Officers and Assistant Extension Officers to identify the problems that could and need to be solved in the near future with low-tec and low-cost. The following problems relating to production and health management were evident during the field visits.

These are the site specific problems that are encountered during actual construction or after the construction of the Bagda farm. The following site specific and engineering defects have led to problems relating to production and health management in extensive and improved extensive Bagda farming systems.

Improper pond bottom elevation leading to difficulties in proper water management.

Exposure of acid sulfate and/or potential acid sulfate soils causing leakage of acid into the pond.

Soil erosion due to improper dike construction leading to high oxygen demand and causing sub-lethal effects.

Low saline water turnover into complete fresh water during rains causing lethal stress.

Pale yellow mottles overlying the sub-soil in many areas, including Bagda farming complexes constructed under both IDA and ADB projects in Rampur, Cox's Bazaar District, indicate the presence of acid sulfates and potential acid sulfates. During heavy rains, the acid soil in the dikes reacts with runoff which mixes with the pond water. This problem is severe in ADB and IDA Bagda farming complexes in Rampur Bagda due to the large exposed surface area of the peripheral dike resulting in greater volume of acidic runoff and to the smaller volume of water in the ponds - shallow water depths present a concentration of acid water. Moreover with this runoff, significant amounts of sediments from the dikes are carried into the pond from the poorly compacted dikes resulting in an increase in oxygen demand in the pond environment and causing gill damage.

Many Bagda farms are situated in low saline areas. During rains these areas go completely fresh. Such fresh water conditions are unfavorable for Bagda farming. Thus the combination of acidic condition, low oxygen and fresh water condition causes stress in Bagda creating an environment for disease outbreaks during the rainy season.

Correcting such site specific and engineering problems needs major engineering modifications at high cost. Therefore pond management practices have to be improved to minimize the detrimental effects of such site specific and engineering faults.

Health management should begin with PL collection for Bagda farming. Conditions observed and procedure followed (described in section 2.6) during collection of PL from the wild, cause significant stress to PL well before stocking. In general the PL reach the farmer for stocking are under stress and in poor quality, which makes them susceptible to diseases and may lead to mass mortality soon after stocking. Poor survival rates observed in Bagda farming may largely be due to significant mortality that occurs soon after stocking due to poor quality of stressed PL. Therefore improving PL quality by avoiding stress caused by handling during collection, sorting and holding should go hand-in-hand with improvements in pond management practices.

Importation of PL from neighboring countries is inevitable due to the shortage of PL for stocking. The SEMBV infection in 1994 in semi-intensive systems coincides well with the importation of PL from Thailand and Taiwan. Similarly, the continuous importation of PL from India for traditional and improved extensive systems cannot be ruled out as a possible cause. Prevention of PL importation need strong policy decisions both for a ban on import and increase of PL supply from hatcheries.

In order to maintain a healthy pond bottom it is essential to clean it prior to filling with water and stocking. As shrimp spend most of their time foraging for food on the pond bottom it is equally important to observe a healthy pond bottom during the culture cycle. Accumulated sediments on the pond bottom consume more oxygen and produce higher levels of ammonia and hydrogen sulfide. Such conditions cause stress to shrimp and increase the incidence of many types of diseases. During field visits, the following shortfalls were observed in the pond preparation method.

The most widely used form of lime is hydrated calcium or calcium oxide. This form of lime should only be used on soil with a pH lower than five. The common practice is to use this form of lime irrespective of the pond bottom soil pH. Hydrated lime when applied to soils with high pH will cause excessive pH in water if the alkalinity of water is low (water with low buffering capacity). High pH levels and frequent fluctuations of water pH in a pond more than 0.5 units cause stress on Bagda. Calcium carbonate or dolomite should be applied on soil with a pH higher that 5. However, lime in the form of calcium carbonate and dolomite is scarce on the Bangladesh market. Farmers are therefore compelled to use calcium oxide in pond preparations. Farmers should be taught and trained to use the correct quantity and frequency of calcium oxide in to avoid the risk of high pH.

Employment of inadequate quantities of lime: The level of lime application will depend on the pond bottom soil pH. It was observed that lime is applied irrespective of pond bottom soil pH. Hydrated calcium is used by the improved extensive farmers at a rate ranging from 10 to 150 kg/acre, which is well below the recommended lowest level of 200 kg per acre for pond bottom soil with a pH greater than six. Inadequate liming will not help to maintain the correct water pH nor to control the fluctuation within a narrow range.

Employment of inadequate quantities of fertilizers: Of the two systems, only the improved extensive farmers use fertilizers during pond preparation. Inorganic fertilizers are commonly used, i.e. urea and tri super phosphate (TSP). Farmers also apply cow-dung at a rate of 500 kg/ha, once only, before filling water. Many farmers use more urea than TSP during pond preparation. Often the fertilization is done once only. The quantity, ratio and frequency of fertilizers should be selected according to the pond conditions of Bangladesh and not those practiced elsewhere. Therefore there is a need to train the farmers on fertilization of ponds applicable to local conditions.

Improper drying of pond bottom: Farmers who are able to dry their ponds, do it in the following manner:

Farmers who are unable to dry their ponds often scrape or plough the top soil layer. Those who dry and plough or scrape usually fill the pond with water soon after. This may expose the sub-soil layer containing a high organic load which creates an unhealthy pond bottom for Bagda. Farmers are unaware of the danger of the potential acidity in the sub-soil layer when ploughing and scraping the top soil layer

When Bagda culture is practiced in alternation with paddy, the stocking of PL is done during February. Stocking of PL is carried out during December when Bagda culture is practiced in alternation with salt production. When the crop rotation is not practiced the stocking of PL is done whenever the PL are available. During the mission the consultant observed that there is a tendency of greater production losses when PL are stocked during unfavorable months (December to January - cold weather; and May to July - rainy season). Low temperature during cold months and fresh water conditions during rainy months stress the PL, leading to significant mortalities soon after stocking or subjecting them to disease as the culture cycle progresses. Thus timing of stocking plays an important role in minimizing production losses and in avoiding problems related to health management. The recommended time for stocking is February to March which coincides with the peak season of natural PL availability and harvest in June without prolonging the culture during the rainy season (see Health Management Consultant's Report - TCP/BGD/6714 Field Document No. 1 for details) .

The elevation of the pond bottom is considered suitable if it enables draining of the pond almost any day of the year and filling it with water to the desired depth within a few days. Inability to drain and fill water in ponds except for full and new moon days is mainly due to high pond bottom elevation (e.g. IDA and ADB sponsored Bagda farming complexes in Rampur, Cox's Bazaar District) or due to narrow tidal fluctuations in areas far from sea mouths (e.g. Bagda farms in Khulna District). This situation has prevented maintaining the desired water depths (1.0 to 1.2 m) for Bagda farming and correcting adverse water quality conditions in the ponds (please see the Health Management Consultant's report for details). The water management in Bagda ponds is made more difficult due to water control gates with inadequate width, depth and openings.

During the consultancy mission, it was seen that many predators such as sea bass, goby, and cat fish were among the by catch. My impression is that farmers do not feel the impact of predation on production losses. It has become a habit to attribute any production below expectation to diseases. No attempts have been made to prevent losses due to predation. Prevention of losses due to predation is an area where farmers need knowledge and training. Farmers should be trained on constructing proper water control structures with proper screens.

It is very clear that correction of many problems (such as pond bottom elevation, exposure of acid sulfate and/or potential acid sulfate soils causing leaking of acid into the pond, increased pond water depth and water exchange rates, avoiding siltation) need high-tech and high cost and may not be acceptable to farmers. It is the consultant's view that making recommendations to correct such technical difficulties would not be practical and acceptable to the farmers. Hence, it is recommended, in close consultation and agreement with international and national staff , to develop a pond management strategy for extension which involves low-tech and low cost. This management strategy involves methods to improve fry quality by reducing stress on them during collection and holding, and improve nursery management methodology during the grow-out phase. Both these activities will make the fry stronger to withstand sub-optimal conditions which already prevail in the pond environment due to the technical problems mentioned above and thereby improve the survival. Two workshops were conducted by both the consultants (Dr. Siriwardena and Dr. Smith) for DOF officials (District Fisheries Officers-DFO's, Thana Fisheries Officers-TFO's, Assistant Thana Fisheries Officers-ATFO's, Extension Officers-EO's and Assistant Extension Officers-AEO's of the four Bagda farming districts) to function as master trainers to train farmers in the future.

3.1 Workshops

These workshops were designed to train the fisheries officers on improved management practice involving low-tech and low-cost as a tool to mitigate the effects of inherited technical problems. The total number of DOF officials attending the two workshops on health management was 115 (40 from Cox's Bazaar District and 75 from Khulna, Satkhira and Bagerhat Districts). In addition to these workshop the consultant conducted two training workshops for fry collectors and fry holders in Ukiya and Moheshkahali in Cox's Bazaar District. There were 50 participants in each training workshop .

The consultant reviewed the existing training programmes and training materials in DOF before designing the workshops. DOF has taken the initiative to set up a facility called Shrimp Cell (Appendix I) to train farmers, fry collectors and depot operators (deheading centre operators) on Bagda culture management, Bagda fry collection, Golda (freshwater prawn) culture management and post-harvest quality control of Bagda. The Shrimp Cell has a ongoing training programme on environmentally friendly Bagda culture management, seed collection and post-harvest quality control. This training programme is designed for both traditional and improved extensive farmers and includes both classroom and field training. Extension material has been prepared to cover almost all aspects of Bagda farming such as site selection, pond construction and preparation, stocking, nursery management water management, feed management, common diseases and health management, harvesting, quality control, packing, transport and marketing. There is no doubt that these extension materials provide a good idea on general Bagda farming. Improvements and redesigning of these training programmes are needed to address the actual situation in extensive and improved extensive systems. For example, the application of lime and fertilizers recommended in the training programme is not appropriate to pond conditions (see Health Management Consultant's report for appropriate pond preparation and nursery management to improve survival of Bagda - TCP/BGD/6714 Field Document No. 1 ).

The workshops highlighted the ways and means of improving fry quality by reducing stress during collection and holding, importance of having a nursery compartment within the grow out pond, how to prepare and maintain a nursery compartment and grow-out pond to make the Bagda strong enough to withstand prevailing unfavorable conditions due to inherited technical problems mentioned previously. (Appendix II).

The following were the main improvements suggested to improve the PL quality and nursery management and maintenance to make them strong enough to withstand the sub-optimal conditions in the pond environment.

Use previously settled clean water in a container with a large surface area without silt and debris, from the same water source fry are being collected from.

Increase water level up to 1.5 to 2 ft. in the cement cubicles used by the fry holders.

Do not scoop the fry to remove from the tank for cleaning. Siphon water using a small net cage to prevent escape of PL.

Encourage PL collection methods based on their clinging habit and use of the improved set-bag type net to remove non-targeted larvae and fry.

Avoid stocking during cold months and rainy season. Stock during February to March and harvest without prolonging the culture during rainy season.

Acclimatize the PL to pond salinity and temperature using pond site tank/container or inside the pond.

Scrape or plough only after having ascertained the pH profiles of sub-soil layers.

Avoid calcium oxide application. If used, apply 0.5 to 1.0 ton for soils with pH greater than 6.0; 1.0 to 1.5 tons for soils with pH 5 to 6; and 1.5 to 2.5 tons for soils with pH less than 5.0.

Use 30 ppm tea seed cake to remove unwanted fish species in the nursery compartment.

If organic fertilizers are used apply 6 to 10 kg/ha/day for two weeks every 2 to 3 day intervals. Organic fertilizers are better for deeper waters.

Use a water control structure with three openings of 1.2 m wide each for efficient water exchange (Appendix III for details).

Use of 3.0 m long, 24 holes/inch (576 holes/inch²) mesh net made into a cone shape bag with a floating trash box at the end of the net as screens. These screens should be fixed to each opening of the water control structure (this will be demonstrated during the cluster training).

(See Health Management Consultant's Report by Dr. Simon Funge-Smith for suggested improvements in proper nursery management and maintenance -TCP/BGD/6714 Field Document No. 1).

3.2 Experimental Demonstration Units (EDU)

During the consultancy mission, it was felt that the most effective way of training and convincing farmers on suggested pond management practices was by demonstrating positive results. Three potential sites have been evaluated for EDU in Rampur (Cox's Bazaar District), Thala (Satkhira District) and Botiagata (Khulna District). In addition to the proposed cluster training there will be an EDU in each district to train farmers on the suggested pond management practices. The demonstration farm established under the ADB project in Rampur is administered by the DOF and situated in close proximity to ADB and IDA Bagda farming complexes, which makes it suitable and desirable for extension. This demonstration facility has been designed to suit the semi-intensive type of culture. Hence, slight engineering modifications are needed (construction of short bunds, demolishing bunds and box sluice) to redesign for the purpose (see Health Management Consultant's on the design and function of the EDU's).

The other two potential EDUs are owned by private farmers. The criteria used for selection were: a farm with a disease history; farm should be owned by the farmer; farmer should have a good educational background; and the farmer should be acceptable to the community. The last two criteria were used with an aim to use the EDU farmer as a trainer to train other farmers.

The private farm in Thala is a 6.8 ha extensive farm situated adjacent to a brackishwater river, although the salinity in the pond may drop to zero during the rainy season. There are permanent staff at the farm who can perform duties if properly supervised. The potential EDU at Botiogata is 6.6 acres and adjacent to a brackishwater river. The farm owner practices improved extensive techniques (see Health Management Consultant's report for funds and functioning of the EDU ). An additional fourth site is recommended in Bagerhat District as this district has contributed significantly to the Bagda farming industry in Bangladesh. A suitable site has already been identified by the consultant in conjunction with the DFO of Bagerhat District at Diagraj in Mongla Thana. The farm covers 10 ha and practices improved extensive fish farming. It has access to Mongli river for water intake.

3.3 Farmer Training

Based on the workshops conducted by the two international consultants, the consultant will conduct during his second mission, forty, one-day ,on-site training programmes with the help of NC's, TFO's and EO's of the DOF. About 30 to 35 farmers will take part in a single, one-day programme, and these programmes will eventually train about 1,200 to 1,400 farmers from all four districts. To facilitate these training programmes the consultant will prepare extension material based on the management practice suggested during the workshops, in English to be translated into Bangla by the NC's.

Eleven, one-day training programmes in Cox's Bazaar District- three for fry collectors and fry holders and eight for farmers.

Eleven, one-day training programmes in Satkhira District- two for fry collectors and fry holders and nine for farmers.

Eleven, one-day training programmes in Khulna District- two for fry collectors and fry holders and nine for farmers.

Seven, one-day training programmes in Bagerhat District- one for fry collectors and fry holders and six for farmers.

Once this training programme is over, the NC's are expected to continue with the training of more farmers, using EDU's.

3.4 Collection of Information

The industry lacks reliable statistical information on the physical and technical aspects of farming, culture practice, water quality, productivity, types and entity of diseases and economics. This information should be collected by the Shrimp Cell to assess the status and sustainable development of the industry. A questionnaire (Appendix IV) has been developed by this consultant to collect information on individual farm profiles. NC's with the assistance of TFO's should collect these data which could be used to select farmers with similar problems in the management practice for effective training.

4.0 NATIONAL CONSULTANT'S SELECTION AND REPORTING

Both international consultants agreed in close collaboration with the NPD on the following responsibilities and selection of candidates and schedule of their appointments.

Assisting and conducting on-site training programmes for fry collectors and fry holders.

Assisting and conducting on site training programmes for farmers of the concepts

Collection of data from farms based on the questionnaire prepared by the consultant regarding farmers, environmental and health management.

The NC's timetable for the first, six-monthly period was outlined in the Health Management Consultant's Report. The second, six-monthly period will be provided by the consultant on completion of his second mission.

5.0 INTERNATIONAL TRAINING

The original project proposal by the FIRI Fish Health Specialist proposes a 'hands-on-training' in shrimp health management in Thailand to train two officers from the DOF and two officers from the Fisheries Research Institute. The officers trained should be the same as those who work on the project to achieve the objectives. During discussions held with FRI officials in Mymensingh, Cox's Bazaar and Paikgacha, they expressed their willingness to contribute their services to the project. By mandate the FRI is involved in the development of skilled technical manpower through training and dissemination of institute developed technologies through demonstration and training. The nature of this project is extension to train farmers on identified problems relating to production and health management. The officials of FRI expressed their doubts in releasing their officers to work on this project. It is essential that the officers trained should continue with the training of farmers. Therefore it is the consultant's opinion that all four officers for overseas training should be selected from the DOF and these officers should remain in shrimp farming districts at least for five years to train farmers.

The consultant wishes to recommended the following personnel for hands-on-training.

Mr. Masudur Rahman (NPD). Mr. Masudur Rahman is the Director/Marine of DOF and functions as the NPD for this project. He is enthusiastic and energetic. He showed tremendous interest in getting involved in the field visits, discussion meetings with field officers and workshops conducted under this project. He is quite knowledgeable in the subject and updating his knowledge through the proposed training will certainly help the smooth functioning of the project.

Mr. Swapon Kumar Dev. Mr. Dev is the DFO/Bagerhat Officer-in-Charge of an important shrimp farming district. The three DFOs in the other three shrimp farming districts will function as NC's. This training will prepare for his direct participation in the project activities.

Mr. Md Abdul Halim. Mr. Halim is the hatchery officer, Shrimp Culture Project (IDA), Cox's Bazaar. Mr. Md Abdul Alim. Mr. Alim is the TFO in Moheshkhali Thana. Both Mr. Halim and Alim have considerable knowledge in the industry. It is the consultant's view that they have the ability to disseminate knowledge and train farmers.

CONSTRAINTS FOR EFFECTIVE EXTENSION

Most of the farmers are not land owners. They are lessees of private land owners on sub-lessees of the lessees of Khas land. The lessees or the sub-lessee farmers are reluctant to invest in the farm since they are on short-term leases, even for certain engineering modifications such as constructing a nursery compartment. Suggested improvements to the management practice are very much dependent on the operation of a nursery compartment within a grow-out pond. Often the lease is renewed annually. Lease rents increase annually. If the present farmer is not in agreement with the increase, the owner seeks another farmer to lease the land. Therefore the Government should intervene to ensure that a farmer gets a long -term lease. The Government at least should ensure that the Khas lands are leased to shrimp farmers. The authorities should take steps to identify the non-farmers who have obtained Khas land for shrimp farming. These lands should be reallocated to the actual shrimp farmers. Identification of non-farmers who have obtained Khas land could be done at the Union level through TFO's. Moreover when Khas lands are allocated on lease agreement it should include a clause to say that if the lessee does not develop the land into a shrimp farm within 6 months after the lease agreement is signed, the authorities have the right to reallocate the land to another farmer.

(See Health Management Consultant's Report - TCP/BGD/6714 Field Document No. 1 on the timing and type of training needed. )

7.0 WORK PLAN

Activity	Time frame	Responsibility
Preparation of extension material for culture training	August 1997	Siriwardene
Preparation of a format to collect information on the farmer, culture practice, water quality, production and health conditions.	August 1997	Siriwardene
Translate into Bangla and preparation of extension material to be used in culture training	September - October 1997	NPD
Collection of information using the questionnaire	October 1997	NC's
Organize and conduct 40 cluster training	December 1997 - January 1998	NPD NC's Siriwardene
Preparation of a workplan for the continuation of cluster training	January 1998	Siriwardene NPD NC's

8.0 CONCLUSIONS

Low productivity in traditional and improved extensive Bagda farming systems in Bangladesh is due to many inherited technical problems such as site specific and engineering difficulties creating a difficult environment for Bagda culture. Attempting to correct these technical faults would not be practical and acceptable to farmers.

Therefore a pond management strategy for extension was developed and discussed with DOF officials during workshops to improve wild collected fry quality and nursery management during the grow-out phase to make Bagda stronger to withstand the inherited poor conditions in the pond environment.

9.0 RECOMMENDATIONS

According to the prevailing environmental conditions in Bangladesh, Bagda culture may be restricted to one crop per year. Stocking should be done during February to March and harvest should be done without prolonging the culture during rainy season.

Bagda farming may be done in alternation with paddy cultivation or in alternation with fresh water prawn or fish during the rainy season.

Bagda farming in alternation with salt should be discouraged since the Bagda culture coincides with the rainy season creating an unfavorable pond environment. Salt production may be carried out in alternation with fish culture to maximize economic benefits.

Establishment of hatcheries to meet the Bagda PL shortage would be viable if operated in alternation with the production of Golda PL. In order to achieve this, equal emphasis should be made on the development of both Bagda and Golda culture industries in Bangladesh.

Until such time as the hatcheries produce an adequate amount of PL, the Bagda farming industry will depend largely on the wild resources for the PL requirement. Therefore, it is essential to initiate a resource survey to monitor this resource for sustainable utilization. This survey may be carried out by the FRI.

Expansion of extensive and improved extensive Bagda farming in new areas should not be encouraged until a realistic solution is made to meet the shortage in PLs supply without import.

The sites selected by the Ministry of Fisheries and Livestock to establish new hatcheries should be reassessed on scientific data as most critical scientific data were not available at the time of survey.

The area of 13,610 ha identified as suitable for semi-intensive Bagda farming by the Ministry of Fisheries and Livestock, should be reassessed on a point-scoring system to evaluate its environmental compatibility.

Semi-intensive farming may be encouraged if the farmer can convince the authorities that he is able to supply his own PL from back-yard hatcheries.

The licensing system adopted by the Divisional Administration should not limit their criteria to identify the real farmer and design of the water control gates. It should be broadened to assess the environmental compatibility of the site for Bagda farming as many production and health management problems in Bagda farms in Bangladesh are due to inappropriate siting.

Guidelines should be drawn up for a legal framework to control expansion of aquaculture in Bangladesh. In this regard the establishment of a committee, consisting of technical and legal personnel and policy makers, is recommended to provide guidelines for a legal framework. This legal framework should include an environmental licensing system.

All farmers should register with the District Fisheries Officer. This could be achieved by registering them at union level with each TFO in order to collect information on the farmer and farm, and to assess the status and level of sustainability of the industry.

The Government should take steps to identify the non-shrimp farmer - lessees who have obtained Khas land for shrimp farming. This identification could be carried out by the TFO's at Union level. Once identified, such Khas lands should be reallocated to shrimp farmers. Conditions of the lease agreement should be revised to include such cancellations and also to relocate the khas lands to actual shrimp farmers, if the original lessee does not develop the land into a shrimp farm within six months of the lease agreement.

All officers for hands-on training should be from the DOF for their full and effective involvement in the project as this project has an important component on extension. Officers from FRI cannot be expected to be involved in full time extension activities.

Candidates identified for hands-on training should work in the shrimp culture districts for a period of at least five years. These officers should not be transferred to non-shrimp culture areas. Transfers may be carried out within shrimp culture districts.

The Backstopping report by the FAO/FIRI Fish Health Specialist proposes to establish 3 EDU's in Cox's Bazaar, Satkhiora and Khulna. It is recommended that the fourth EDU be set up in Bagerhat District as this district contributes significantly to the Bagda farming industry. A suitable site has already been identified. These EDU's would be to train farmers on the suggested pond management practices. The owners of each EDU should function as a trainer in consultation with DFO Officials to carry out farmer-to-farmer training. Continuation of these EDU's after the project termination should be the responsibility of the DFO of each district under the direct supervision of the Director, Marinating.

After its establishment, the continuation of the EDU at the ADB project site in Rampur should be ensured by the Director/Marine of DOF through self income generation.

To assess the effectiveness of the suggested management practices on the productivity of a traditional and improved extensive Bagda farming industry in Bangladesh.

Upgrading of Golda farming industry in Bangladesh. This upgrading of the Bagda farming industry is essential for the viability of hatchery and farming industries of Bagda as an industry to do in alternation. Upgrading of Golda farming should include zonation of suitable areas for culture and extension of management practice on culture and hatchery operation.

To initiate a resource survey to monitor the wild PL resource for sustainable utilization due to the socio-economic importance of this industry and due to the fact that the traditional and improved extensive culture largely depends on this resource.

Appendix I

The Ministry of Fisheries and Livestock (see Memo No. SAM-2 (Misc.) - 2/94/53 dated 12.3.94) formed/ organized Central Prawn/ Shrimp cell headed by Director (Marine) of DOF with nine supporting officers and staff. The main objectives of the Shrimp Cell are:

Collection, preservation and distribution of all kinds of information relating to shrimp/prawn resources.

Development of sustainable technology for improved prawn/shrimp farming and providing technical assistance to the entrepreneurs.

Technical assistance to private entrepreneurs for establishment of prawn/ shrimp hatcheries.

Conduct training, extension work, etc. for improved/semi-intensive prawn /shrimp farmers and prawn /shrimp hatchery operators.

The Central Prawn/Shrimp Cell established one information-cum-documentation-cum-training room on the 4^th floor of the Matshya Bhaban, Dhaka. The two Regional Prawn/Shrimp Cells are also operating with 8 supporting officers and staff at Khulna and Cox's Bazaar.

Appendix II

These workshops were intended to provide knowledge on the problems relating to production and health management in the Bagda farming industry and the management practices that have to be developed for sustainable Bagda farming in traditional and improved traditional system in Bangladesh. It is expected that the trainees in these workshops will function as trainers to train farmers to deal with local problems for sustainable farming. The resource personnel for these two, 3-day workshops were : Dr. S. N. Siriwardena (International Consultant on extension) and Dr. Simon Smith (International Consultant on Shrimp Health Management).

A technical overview of the shrimp farming industry in Bangladesh - Dr. S. N. Siriwardena.

Disease conditions in Bangladesh traditional and improved extensive ponds - Dr. Simon Smith

Pond side demonstration of shrimp health checks and discussion on pond management problems - Dr. Simon Smith and Dr. S.N. Siriwardena.

Appendix III

i The floor elevation of the main gate should be lower than the lowest pond bottom elevation.

single opening of 1.0 m main gate could fill a 10-15 ha pond in 2-3 successive high tides - suitable for milkfish farm.

- a gate with 3 openings of 1.2 m wide would fill an 11.35 ha shrimp farm (1.0 m water depth) in 2 consecutive tides.

Appendix IV

INFORMATION ON FARMERS, CULTURE PRACTICES, HEALTH STATUS AND PRODUCTION ECONOMICS

Location: Thana:.................................................. Union: ......................................................

Date and time of inspection: ....................................................................................................

Farmer's name and address: ..................................................................................................

..................................................................................................

Educational level or ability to read and write: ..........................................................................

Years of experience in shrimp farming: ....................................................................................

Total land area: ........................ No. of ponds: .................... Approx. water area: ..................

Number of gates: ..................... Size of inlet: ....................... Size of outlet: ...........................

Number of nurseries: ...................................... No nursery operation

Area of nursery/s: ....................................................................................................................

Lime application: Type/s ..................................................................................................

Rate/ Frequency: ..................................................................................

Fertilizer application: Type/s ..................................................................................................

Rate/ Frequency: ..................................................................................

Feeding: Type .....................................................................................................

Rate/ Frequency: ..................................................................................

Stocking density: Bagda: ..................................... Other shrimps: ............................

Methods of estimation of survival rate in the nursery: ..............................................................

Lime application: Type/s ..................................................................................................

Rate/frequency: ....................................................................................

Fertilizer Type/s: .................................................................................................

Rate/frequency: ....................................................................................

Feed: Type/s: .................................................................................................

Rate/frequency: ....................................................................................

Salinity: Nursery ........................................ Grow Out: .............................................

pH: Nursery ........................................ Grow Out: .............................................

Alkalinity: Nursery ........................................ Grow Out: .............................................

Bottom DO: Nursery ........................................ Grow Out: .............................................

Antennae and appendages: Damages: ......................................................................

Appendix V

Date	Organization and Person/s	Subject/Activity
29^th May	Arrive in Bangkok
30^th May	FAO/RAPA Ms. D. Blessich (FAO/RAPA) Dr. Rohana Subasinghe (FIRI) Dr. Simon Smith	Briefing-TCP/BGD/ 6614(A)
02^nd June	FAO/RAPA Ms. D. Blessich	Briefing TCP/BGD/6614(A)
03^rd June	Depart for Bangladesh Arrive in Bangladesh	11.25 a.m 1.00 p.m
04^th June	FAO/ Bangladesh Mr. H. Konuma (FAOR) Dr. R. Subasinghe (FIRI) Mr. Md. Saleem/ Programme Officer (FAOR Office)	Discussion of TOR arrangements to visit Cox's Bazaar
05^th June	Depart Dhaka for Cox's Bazar Dr. R. Subasinghe(FIRI) Dr. Nitya Nanda Das (DFO/ Cox's Bazar)	Discussion of project objectives. Arrangements for visit farms.
06^th June	Dr. R. Subasinghe (FIRI) Mr. MD. Muniruzzaman (TF--) Mr. Md. Shamsuddin Elias Project Officer (ADB)	Visit farms in Chokoria
07^th June	Dr. R. Subasinghe (FIRI) Mr. Md. Masudur Rahman (NPD) Dr. Nitya Nanda Das (DFO/ Cox's Bazaar) FRI Officers, Fisheries Officers and representatives from extensive and semi-intensive farms	Discussion meeting on the objectives of the project and problems in the industry in Cox's Bazaar District.
08^th June	Travel to Jessore Travel to Satkhira Dr. R. Subasinghe (FIRI) Mr. Md. Masudur Rahman(NPD) Mr. Habibur Rahman (DFO, Satkhira) Dr. Aftahuzzaman (Secretary General/Bangladesh Frozen Food Export Association)	Visit farms in Satkhira. Discussions of the project objectives and the problems in the industry. Travel to Khulna via Satkhira
09^th June	Dr. R. Subasinghe (FIRI) Mr. Md. Masudur Rahman (NPD) Mr. Rizaul Karim (DFO/Khulna) Mr. (DFO/Bagerhat)	Visit shrimp farms in Khulna and Bugerhat
10^th June	Dr. R. Subasinghe (FIRI) Mr. Md. Masudur Rahman (NPD) All DFO's and Fisheries officers from Satkhira, Khulna and Bagerhat	Discussion meeting on the objectives of the project and problems in shrimp farming in Khulna, Satkhira and Bagerhat Districts.
11^th June	Travel to Dhaka Dr. R. Subasinghe (FIRI) Mr. Md. Masudur Rahman (NPD) Mr. Chandra Chanda (AD/DOF) Mr. Konuma	Discussion on the appointment of the National consultants Mission up date

12^th June	Mr. Imtiazudeen Ahmed (Snr. Programme Officer World Bank Office)	Discussion on the 3^rd Fisheries Project.
13^th June	Far Pavillion Guest House	Report writing
14^th June	Mr. Imtiazudeen Ahmed (Snr. Programme Officer World Bank Office) Dr. Shah (Programme Officer FAO)	Discussions on the Socio- economic survey of 3^rd Fishery Project. Travel arrangements for field visits.
15^th June	Mr. Masudur Rahman (NPD)	Review of extension work carried out by DOF and discussion on the work programme.
16^th June	Mr. Swapan Chandra Paul (OIC/ Shrimp Cell/DOF)	Review of extension material prepared by Shrimp Cell/DOF.
17^th June	Travel to Mymensingh FRI Dr. Gulam Hussain (CSO) Dr. Suharh Chakraborti Dr. Ramatullah Dr. Mano Ranjan Das (Dept. Aquaculture/BAU)	Discussions on the role of FRI and BAU on problems related to shrimp farming.
18^th June	Dr. Md. Kamal(Addl Director FRI)	Discussion on the possible effective interaction between DOF and FRI on solving problems related to shrimp farming. Travel to Dhaka
19^th June	Travel to Cox's Bazaar Dr. Nitya Nanda Das (DFO/ Cox's Bazaar(NPD) Mr. H. Konuma (FAOR)	Visit hatcheries. Discussion on the damage caused by cyclone in May 1997.
20^th June	Mr. H. Konuma (FAOR) Mr. Masudur Rahman (NPD) Dr. Nitya Nanda Das (DFO/ Cox's Bazaar)	Visit IDA and ADB shrimp farm complex. Visit abandoned due to bad weather.
21^st June	Depart of Mr. Konuma for Dhaka Mr. Dayal Chandra Ghosh (TFO) Mr. Abdul Haleem ( Hatchery Officer/ IDA)	Visit semi-intensive and extensive farms in Teknof.
22^nd June	Mr. Samsudeen Elias ( Project Officer/ ADB) Mr. Sukumar Roy (EO/ADB)	Visit ADB shrimp farm complex in Rampur.
23^rd June	Mr. Dayal Chandra Ghosh (TFO) Mr. Md. Moniruzzaman (TFO)	Training workshop for fry collectors and fry holders in Ukiya Thana
24^th June	Mr. M. N. Sorker(OIC/ Marine Fisheries Project) Mr. Abdul Alim (TFO)	Training workshop for fry collectors and fry holders in Moheshkhali Thana.
25^th June	Dr. Nitya Nanda Das (DFO/ Cox's Bazaar All TFO's, ATFO's, EO's and AEO's of Cox's Bazaar District Dr. Abul Hussain (PSO-FRI/Cox's Bazaar)	Discussion meeting on the problems related to production and health management. Research activities of FRI on shrimp farming industry.

26^th June	Depart Cox's Bazaar for Dhaka, 12.40 hrs Arrive in Dhaka, 14.00 hrs.	Rest day.
27^th June	Far Pavillion Gust House	Report writing
28^th June	Far Pavillion Gust House	Report writing
29^th June	Mr. Masudur Rahman (NPD) Mr. Swapon Chandra Paul (OIC Shrimp Cell/DOF)	Discussion meeting on the findings during the visit to Cox's Bazaar District.
30^th June	Mr. Swapon Chandra Paul/ OIC Shrimp Cell Mr. Masudur Rahman (NPD)	Discussion on the revision of extension material. Discussion on the site selected for EDU at Cox's Bazaar and modifications needed.
01^st July	Depart Dhaka for Jessore 8.00 hrs. Arrive in Jessore 8.30 hrs. Arrive Satkhira 10.30 hrs Mr. Habibur Rahman (DOF/ Satkhira District) Mr. Shariful Islam (AFO)	Discussion on the arrangements of field visits Visit to Gramin Bank Fram at Satkhira Sodur Thana.
02^nd July	General Strike until 14.00 hrs. Mr. Mohoshin Uz Zaman (TFO) Mr. Serazur Rahman (TFO)	Visit farms sites at Bakal, Satkhira Sodur Thana
03^rdJuly	Mr.Mohoshin Uz Zaman (TFO) Mr. Serazur Rahman (TFO)	Visit farm sites at Debhata Thana
04^th July	Mr. Habibur Rahman (DOF/Satkhira) Mr. Serajur Rahman (TFO) Mr. Shariful Islam (AFO)	Visit farm sites at Kulia Durgapur, Kalingong Thana
05^th July	Mr. Habibur Rahman (DOF/Satkhira) Mr. Mizanur Rahman (TOF) Mr. Shahidul Islam Sarda (TFO)	Visit farm sites at Paniya, Kalingong Thana and Shymnagar Thana
06^th July	Mr. Habibur Rahman (DOF/Satkhira) all TFO's, ATFO's EO'S and AEO's of Satkhira District Mr. Amal Kanshi Roy (TFO) Mr. Mohshin Uz Zaman (TFO)	Discussion meeting on problems related to production and Health Management Visit fresh water prawn farm sites at Kolorva.
07^th July	Mr. Md. Mohsinuzzaman Mr. Rizaul Karim (DFO/Khulna) Mr. J. N. Islam (TFO)	Visit farm sites at Tala. Selection of EDU for Satkhira District Travel to Khulna Visit farm sites at Dumaria
08^th July	Mr. Shiekh Ali (TFO) Mr. Ziaul Hoqum (EO) Mr. S.M. Rahman (Sec. Shrimp Farming Association)	Visit farm sites at Paikgacha Visit Brackish Water Fisheries Station /FRI
09^th July	Mr. Amerul Islam (Snr. Ass. Sec/ MFAL) Mr. Rizaul Karim (DFO/Khulna) Mr. Abdul Mannan(TFO)	Visit farm sites at Dacope.
10^th July	Mr. Masudur Rahman (NPD) Mr. Rizaul Karim(DFO/Khulna Mr. Swapon Kumar Dev (DFO/Bagerhat) All TFO's, ATFO's EO'S and AEO's of Khulna and Bagerhat Districts	Discussion meeting on the problems related to production and health management.

11^th July	Mrs. Anjalie Halder(TFO) Mr. Swapon Kumar Dev (DFO/Bagerhat) Mr. Shawmesh Chandraw (TFO).	Visit farm sites at Ruksha. Travel to Bagerhat District Visit farm sites at Bagerhat District and selection of the site for fourth EDU
12^th July	Travel to Jessore Dr. Rizaul Hassan (DANIDA Project)	Discussion on the development of fresh water prawn industry.
13^th July	Travel to Dhaka (Morning flight) Mr. Hiroyuki Konuma (FAOR)	Mission update
14^th July	Mr. Masudur Rahman (NPD) Mr. Swapon Chandra Paul(OIC/ Shrimp Cell) Mr. Chandra Chanda (AD/DOF)	Briefing of the findings during visit to Satkhira, Bagerhat and Khulna Districts. Discussion meeting on the planning of two three-day workshops and set up of EDU's.
15^th July	Mr. Swapon Chandra Paul(OIC/ Shrimp Cell) Mr. Masudur Rahman (NPD) Secretary, Ministry of Fisheries and Live stock	Outlining the extension material required for training. Meeting to discuss the project activities and progress.
16^th July	General Strike Far Pavillion Guest House	Report writing
17^th July	FAO, Office, Dhaka	Report writing
18^th July	Far Pavillion Guest House	Report writing and preparation of material for workshops
19^thJuly	Far Pavillion Guest House	Preparation materials for workshops
20^th July	FAO, Office, Dhaka	Arrangements and preparation material for workshops
21^st July	Arrival of Dr Simon Smith ( Consultant on Health Management. Mr. H. Konuma (FAOR Dhaka)	Discussion progress and mission objectives. Explain mission objectives.
22^nd July	Dhaka- Chittagong Chittagong- Cox's Bazar Dr. Smith (Consultant on Health Management).	Arrive 1.00 pm Arrive 5.00pm Visit District Fisheries Office (DFO) Cox's Bazaar to arrange itinerary. Informed of unavailability of DFO Cox's Bazaar.
23^rd July	Teknaf District Dr. Smith (Consultant Health Management) Mr. Alim (TFO Teknaf)	Visit traditional farms and discuss production problems with sub- District (Tanah) Fisheries Officer and farmers. Visit to discuss semi- intensive farm and nursery now converted to fish culture.
24^th July	Rahmpur District Dr. Simon Smith (Consultant Health Management) Mr. Alim (TFO Moheshkhali) Mr. Masadur Rahman (NPD) Dr. Nitya Nanda Das (DFO/ Cox's Bazar)	Visit ADB shrimp project site and demonstration unit. Visit IDA shrimp culture site and discuss problems with farmers. Discuss shrimp production problems in Bangladesh finalize workshop arrangements.
25^thJuly	Cox's Bazar. Dr. Simon Smith (Consultant Health Management) Mr. Masadur Rahman (NPD)	Day-1 Officers discussions and lectures Thana Officers training workshop in shrimp health management and improved production techniques.

26^th July	Cox's Bazar Dr.Simon Smith (Consultant Health Management) Mr. Masadur Rahman (NPD)	Day-2 lectures and practical problems solving thana Officers workshop in shrimp Health management and improved production techniques.
27^th July	Cox's Bazar Dr. Simon Smith (Consultant Health Management)	Day-3 field visit Thana Officers training workshop in shrimp Health management and improved production techniques.
28^th July	Cox's Bazar- Chittagong Dr. Smith (Consultant on Health Management). Chittagong- Dhaka	Finalize arrangements for travel to Khulna. Arrive Dhaka 6.30 pm.
29^th July	Dhaka- Jesore Dr. Rezaul Hasan (DANIDA Oxbow Lakes-Small Scale Fishermen Project) Dr. Simon Smith (Consultant on Health Management). Satkhira Dr. Simon Smith (Consultant on Health Management). Thala Dr. Simon Smith (Consultant on Health Management).	Arrive 8.30 am Discussed production strategies from extensive fresh water systems and potential problems of freshwater shrimp production. Discuss potentials of cage fish cultivation in Bangladesh. Meet Satkhira Thana Fisheries Officer Visit farms Visit shrimp processing factory. Discussed current market and shrimp collection/ processing strategy. Visit proposed Demonstration Farm. Evaluate change required and discuss production history of farm with owner.
30^th July	General Strike Khulna Mr. Md. Rezaul Karim ( DFO Khulna) Dr. Simon Smith ( Consultant Health Management).	Further discussions on shrimp farm situation and coastal aquaculture development. Finalize arrangements for training workshop Request inclusion of all sub- district fisheries officers in training workshop.
31^st July	Domuria Dr. Smith (Consultant Health Management). Mr. Md. Rezaul Karim (DFO/ Khulna) Botiagata Dr. Simon Smith (Consultant Health Management).	Visit shrimp farms and discuss culture problems with local farmers. Visit potential demonstration farm Discussion regarding requirements for farm with owners.
1^stAugust	Khulna Dr. Simon Smith (Consultant Health Management).	Day-1 Lectures and Officers discussions DOF Officers training workshop in shrimp health management and improved production techniques.
2^nd August	Khulna Dr. Simon Smith (Consultant Health Management).	Day-2 Lectures and practical problems Solving DOF Officers training workshop in shrimp health management and improved production techniques.

3^rd August	Khulna (Botiagata) Dr. Simon Smith (Consultant Health Management). Jesssore Dr. Rezaul Hasan (DANIDA Oxbow Lakes Small Scale Fisherman Project).	Day-3 Field visit DOF Officers training workshop in shrimp health management and improved production techniques. Visit Macrobrachium hatchery and advice on health, water quality and nutrition problems causing low production and survival.
4^th August	Jesssore- Dhaka Dhaka	Arrive 10.00am Prepare project material with Dr. Simon Smith
5^th August	Dhaka Mr. Masadur Rahman (NPD) Dr. Simon Smith (Consultant Health Management) Mr. H. Konuma (FAOR)	Discuss overseas training Finalize equipment list Discuss NC workplan, reporting and assistance Discuss progress
06^th August	Depart Dhaka for Bangkok Arrive Bangkok	2.00 pm 5.30 pm
07 August	FAO/RAPA Mrs. Dora Blessich	Debriefing
08 August	NACA Dr. Mike Phillips FAO/RAPA Mrs. Tum	Discussion on the NACA home page and receiving information on the aquaculture industries in various countries Travel claim
09 August	Saturday
10 August	Depart Bangkok for Colombo Arrive in Colombo	21.45 hrs 23.59 hrs

Division	District	Extensive and Improved Extensive Farms		Semi-intensive Farms
		Number	Area (ha)	Number	Area (ha)
Khulna	Khulna	2989	36719	06	82
	Satkhira	5061	34858	24	114
	Bagerhat	3427	45259	-	-
Chittagong	Cox's Bazaar	1599	17652	43	779
Total		13076	134488	72	995

Item	Unit price	Price paid
PLs
Lime
Fertilizer
Feed
Fuel
Labor
Lease/Rent
Pond maintenance
Security
Others (specify)

DISEASE PREVENTION AND HEALTH MANAGEMENT IN COASTAL SHRIMP CULTURE

Table of Contents

ACKNOWLEDGMENTS

1.0 INTRODUCTION

2.0 AN OVERVIEW OF THE COASTAL SHRIMP CULTURE IN BANGLADESH

2.1 Resource Availability

2.2 Resource Allocation and Utilization

2.3 Seed Resources

2.3.1 Hatchery Bred PL to Meet the Short Supply

2.4 Shrimp Production

2.5 Farming Systems

2.6 Culture Practice

2.7 Disease Situation in Bangladesh Shrimp Culture

3.0 EXTENSION STRATEGY

3.1 Workshops

3.2 Experimental Demonstration Units (EDU)

3.3 Farmer Training

3.4 Collection of Information

4.0 NATIONAL CONSULTANT'S SELECTION AND REPORTING

5.0 INTERNATIONAL TRAINING

CONSTRAINTS FOR EFFECTIVE EXTENSION

7.0 WORK PLAN

8.0 CONCLUSIONS

9.0 RECOMMENDATIONS

Appendix I

Appendix II

Appendix III

Appendix IV

Appendix V

Type	Weight/year (kg)	Price/kg (Taka)
Bagda
Other shrimp
Fish