3. STOCKING UNDER THE SECOND AQUACULTURE DEVELOPMENT PROJECT (SADP)
Under the SADP, a stocking programme was undertaken on the floodplains of the north-eastern region of Bangladesh. In this region there are two types of floodplain, one called haor, and one having one or more deeper areas that retain water throughout the year called beel. During the rainy season a haor becomes a vast sheet of water with a number of beels into which fish migrate through canals from rivers. Suitable parts of beels were used for carp nurseries. After harvesting fish from the beels they were embanked with submersed dikes and made suitable as nurseries by manuring, and by eliminating predators and other undesirable species with piscicides. Then hatchery produced carp hatchlings (3–5 day old) purchased through contractors and from a government hatchery were stocked and reared up to 5–12 cm; the fingerlings were then dispersed in the surrounding floodplain when the nursery was flooded. Starting with 200 ha of beel nursery in the 1991 there was provision of 1600 ha beel nursery in 1996. But in reality a maximum of 1000 ha of beel nursery could be stocked. A major problem for beel nursery in this region is flash floods which damage or wash away the nursery. The species composition in the beel nursery was silver carp 16.7–38.2%, common carp 3.9–8.6%, rui 21.6–36, catla 5.1–20.3%, mrigal 16.4–20.3%, kalibous 0.6%, sarputi 3%. The stocking density was more or less 1 kg of hatchlings per hectare. The stocking programme using beel nursery fingerling production system was undertaken during 1991–1996. A total of 2498 kg of hatchlings (861 million) were stocked, which produced an estimated quantity of 324 million fingerlings (5–10 cm). The fingerlings were dispersed in the surrounding floodplains.
The direct stocking of fingerlings was implemented in Hail haor (13,000 ha), District Moulavibazar, under the Third Fisheries Project.
4.1 Benefits of stocking
4.1.1 Third Fisheries Project (TFP)
Incremental yield, benefit and cost
A total of 149,500 ha of floodplain area were stocked during six years with 2524.2 tonnes of carp fingerlings. An incremental yield of about 20,000 tonnes of stocked fish was produced. Strict conservation measures taken to protect the stocked fingerlings also resulted in an incremental production of about 13,000 tonnes of non-stocked fish in the floodplains. Yield per ha varied from 9 kg to 281 kg with an average of 214 kg/ha. Average incremental yield would be 234 kg/ha if the abnormal drought year 1992 is excluded from the calculation. Production of stocked quantity of fingerlings varied in different floodplains in different years from 1.5 to 16 times, with an average of 8. Table 3 shows incremental fish yield of both stocked and non-stocked species of fish from baseline (pre-project) year to 1996. The increases per ha in stocked species (carp) and non-stocked species are given in Figs. 2 and 3. Benefit-cost ratio was very encouraging and sustainable.
Figure 2. Increases in carp production due to stocking.
Figure 3. Impact of stocking on non-stocked species.
Stocking of floodplains under TFP continued for 6 years starting in 1991. In all, 26 floodplains have been stocked in one year or another with a total of 23 stocked in 1996, the final and last year of the project. In the economic analysis 8 floodplains having sufficient and statistically sound data have been included Two sets of economic analysis were done. One analysis shown in Table 4 was made under the assumption that the stocking would continue for 20 years. The other analysis depicted in Table 5 was undertaken assuming that there would be no further stocking after 1996 because the DoF and NGOs have no resources to stock and local communities and beneficiaries are not yet sufficiently organised to continue on their own. In the analysis all costs incurred were included and 75% of financial benefits were assumed as economic benefits. ERR of 1st set stood at 38.1% and later at 29.7%. This analysis has been done using a simple approach which is given below.
Table 4. Third Fisheries Project. Economic analysis of the floodplain stocking of selected beels (actuals to 1996, constant thereafter).
|Area Stocking (ha)||3,700||13,200||14,700||22,200||14,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200||22,200|
|Stocking Quantity (kg)||73,049||253,874||249,094||428,606||265,658||325,539||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591||358,591|
|Stocking Density (kg/ha)||20||19||17||19||19||15||16||16||16||16||16||16||16||16||16||16||16||16||16|
|Average Catch Price (Tk/gk)||26||30||34||34||32||35||35||35||35||35||35||35||35||35||35||35||35||35||35|
|Fishermen labour costs||634||5,696||8,645||10,991||9,922||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591||11,591|
|Fishermen equipments costs||912||8,731||13,458||18,167||14,688||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026||20,026|
|DOF Admin costs||2,065||9,165||13,987||17,735||7,998||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195||10,195|
|Total Financial Costs||8,666||46,403||65,927||89,466||59,936||76,360||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195||80,195|
|Total Financial Benefit||0||18,086||15,576||73,659||150,336||107,970||128,931||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369||142,369|
|Net Benefits (Tk'000)||(7,366)||(24,069)||(13,436)||76,840||26,868||41,426||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848||52,848|
|Net Ceon Benefits||171,812|
|NPV @ 12%||38.10%|
Table 5. Third Fisheries Project. Economic analysis of the stocking of selected beels (actuals to 1996,) assuming stocking ends in 1995.
|Area Stocking (ha)a/||3,700||13,200||14,700||22,200||14,200||22,200|
|Stocking Quantity (kg)||73,049||253,874||249,094||428,606||265,658||325,539|
|Stocking Density (kg/ha)||20||19||17||19||19||15|
|Average Catch Price (Tk/kg)||26||30||34||34||32||35|
|Fishermen Labour Cost||634||5,696||8,645||10,991||9,922||11,591|
|Fishermen Equipment Cost||912||8,731||13,458||18,167||14,688||20,026|
|DOF Admin Costs||2,065||9,165||13,987||17,735||7,998||10,195|
|Total Financial Costs||8,666||46,403||65,927||89,466||59,936||76,360|
|Total Economic Cost||7,366||39,442||56,036||76,046||50,947||64,906|
|Benefits (Tk 000)|
|Total Financial Benefit||0||18,086||15,576||73,659||150,336||107,970||128,931|
|Total Economic Benefit||0||15,373||13,239||62,610||127,787||91,775||109,591|
|Net Benefits (Tk'000)||(7,366)||(24,069)||(13,436)||76,840||26,868||41,426||52,848|
|Net Ceon Benefits||42,020|
|NPV @ 12%||29.70%|
Cost of fingerlings stocked under TFP and SADP
For the cost of fingerlings at stocking, including nursery preparation, transportation of hatchlings and management, etc., for beel nursery systems and direct fingerling stocking systems (including transportation, management, etc., see Table 7). Cost per fingerlings has been estimated at Tk. 0.15 for beel nurseries, Tk. 1.04 for direct fingerlings stocking under SADP and Tk. 0.83 for direct fingerling stocking under TFP. This suggests that the beel nursery system of stocking is more cost effective considering no other risk factors. Further fingerlings raised in beel nurseries are automatically dispersed in the same environment and should have a better chance of survival than the fingerlings transported from distant places and released in floodplains. However, taking the survival rate of fingerlings at 10% for beel nurseries, 25% for direct fingerling stocking for SADP and 15% for fingerling stocking for TFP, the cost per fish harvested within 4–5 months of stocking, having an average weight of 400 g, has been estimated at Tk. 0.78 for beel nurseries, Tk. 4.10 for direct fingerling stocking under SADP, and Tk.4.85 for TFP.
Survival rate of hatchlings to fingerlings under SADP was estimated at 37.6%. Details of the 5-year stocking programme in respect of area stocked, quantity of hatchlings stocked, survival rate, etc., are shown in Table 6. Survival from fingerling to harvestable size (av. 400 g) has been estimated at 10% for the beel nursery system while that for the direct fingerling stocking system has been found to be 25% under SADP. Details of stocking under SADP are furnished in Table 7.
Social impact and benefits under TFP
Considering the final year stocking in 23 floodplains, it appears that more than 85,000 fishermen, each heading a family, have reaped benefits from this stocking programme. Three categories of fishermen have been found in the floodplain areas. They are full-time (depending mainly on fishing), part-time (partly/seasonally dependent on fishing), and subsistence fishermen (who fish seasonally partly for house consumption and/or for sale). Full-time, part-time and subsistence fishermen comprise 22%, 28% and 50% respectively. From a socio-economic and fish consumption study (BCAS, 1995) for three floodplains it is evident that their income and different assets shown in Taka and rate of daily fish consumption have increased. This is shown in Table 8. One NGO named Pramoda, who worked in one floodplain in Rangpur, and another NGO named Pradipon, who worked in BSKB in Khulna, reported better socio-economic status of local fishers resulting from the fingerling stocking programme. Also about 2.5 million man-days of casual labourers for nursing and raising of fingerlings and a large number of man-days of daily labourers for transportation and marketing of fingerlings and food fishes was generated due to this programme.
Table 6. Second Aquaculture Development Project. Production of fry by beel nursery.
|Area of beel nursery (ha)||Quantity (kg) of hatchling stocked (million)||Production||Area (ha) of beel nursery||No. of beels||Quantity (kg) of hatchling stocked||Estimated no. of hatchling (million)||Estimated no. of fingerling (million)||Survival rate (hatchling to fingerling)|
Note: 1 kg hatchlings = 347,000 individuals
Table 7. Second Aquaculture Development Project. Cost of fingerling raising in beel nursery and cost of harvest.
|Year||Beel Area (Ha)||Ouantity of hatchling stocked (kg)||Cost fingerlings raised and stocked||Estimated production and cost at harvest|
|Total Cost (preparation of nursery, hatchling, transportation & labour)||Per ha cost (Tk.)||Estimated no. of fingerlings raised and stocked||Cost per fingerling (Tk.)||at 50%survival rate||at 15%survival rate||at 10%survival rate|
|Cost per fish (Tk.)||Production 000 tonnes||Production 000 tonnes||Cost 000 tonnes||Production 000 tonnes||Cost 000 tonnes|
1 kg hatchlings = 400,000 individuals
Table 8. Impact of floodplain stocking under TFP on local fishermen.
|Sl. no.||Indicator||Name of floodplain|
|% of increase||4||14||5|
|2||Fishing right assets|
|% of increase||104||15||7|
|% of increase||23||33||13|
|4||Fishing gear assets|
|% of increase||10||2||3|
|% of increase||31||100||12|
|% of increase||550||105||147|
|7||Per capita daily fish consumption (g)|
|% of increase||140||222||180|
|% of increase||7||11||2|
All pre- and post-project figures except serial 7 are at 1994 Taka and 7 is in grams
|Number of persons per family||: 61|
|Pre-project period||: 1991–92 Financial Year (July-June)|
|Post-project period||: 1993–94 Financial Year (July-June)|
Ref.: Bangladesh Centre for Advanced Studies, 1995
Environment and biodiversity under TFP
A limited study was done on environmental and biodiversity issues as there was no specific programme for it. It was found that one floodplain (BSKB), with an easy inflow and outflow of water, gave a continuous upward trend of production of both stocked and non-stocked fish species. On the other hand, catches of both stocked and non-stocked species gradually decreased in another floodplain (Garalia) where inflow and outflow of water decreased due to siltation of canals and water gates (Islam, 1997). The Shannon biodiversity indices calculated for three floodplains do not indicate any loss of fish biodiversity in terms of richness and evenness due to project stocking (TFP, 1996). TFP, for the first time in Bangladesh, tried to make the hatchery/nursery operators and owners aware of the possible on-going genetic degradation of hatchery-produced hatchlings and fry and motivate them to take corrective measures. This project gathered very interesting and useful data and information which can be profitably used in future projects and studies.
Stocking fingerlings at 15–20 kg/ha with appropriate species mix can profitably produce additional fish by utilising nutrients and natural food of vacant niches of a floodplain ecosystem without hampering any production of non-stocked species and biodiversity. Silver carp has been found to be the most unsuitable because of its high rate of migration to outside of the stocked area. On the other hand, common carp has been found to be the most profitable and favoured species because of its high rate of survival and production (Islam, 1997). Catches of both stocked and non-stocked species of fish have gradually declined in one floodplain where inflow and outflow of water have decreased due to siltation of canals and sluices. However, an increasing trend in production of both stocked and non-stocked species has been found in floodplains where controlled water exchange has continued. Stocking with a weight increase factor of 10 and above (compared with stocked weight) has proven to be economically viable. There is some controversy with regard to the effective water area (1 metre depth for 4–5 months) as the area could not be measured and was estimated visually and by gathering information from different sources. In the final year areas of 12 floodplains were measured by using GIS and it was found that the area of 6 floodplains was higher and that of the other 6 was lower than the estimated area. As a result the density of stocking and yield per ha of the stocked area on which calculations were done would vary to some extent.
SADP has some weaknesses. There was no arrangement for intensive monitoring of fish production and a socio-economic impact study. Floodplain-based beel nursery, although found to be more cost effective, had a risk factor of flash floods and negative impact of biodiversity due to the use of piscicide (rotenone) during the preparation of the nursery for stocking carp hatchlings.
For the compensation of loss of fish production due to environmental degradation the Bangladesh enhancement programme for floodplain fisheries through fingerling stocking is unique and the first approach of such kind in the world. The current project has demonstrated technological and economical viability of fingerling stocking in the floodplains, but the financial and managerial viability and sustainability have yet to be demonstrated. Many factors, including hydrology, rainfall, floodplain productivity, growth period, stocking density, species mix, conservation measures and effective community participation have been found to determine success and sustainability of stocking.
6. RECOMMENDATIONS AND CONCLUSIONS
Future projects and programmes should include both compensatory measures such as stocking and mitigation measures for improvement and protection of fish habitat and wetlands. Mitigation measures should include establishment of sanctuaries, excavation/re-excavation of canals, water estates (Jalmahals), stocking broodstock of fish species whose populations have been declining or are under threat, and ensuring suitable structures for easy movement of fish. Community-based management, both in public stocking in larger floodplains and private stocking in smaller and more or less well defined floodplains, should be undertaken and continued. Legal and institutional problems over access by users/fishers to government owned estates need to be solved, particularly the scope of common property rights to flooded land and how to develop effective and active participation of local communities and local governments (Thana and Union). Different bio-socio-economic fisheries management models for different categories of floodplains are needed. Considering the immense scope and potential of floodplains for increasing fish production and poverty alleviation greater emphasis should be given to the enhancement of floodplain fisheries.
BCAS. 1995. Post-intervention food consumption study, Third Fisheries Project. Bangladesh Centre for Advanced Studies, Dhaka, Bangladesh.
DoF. 1986. Water Area Statistics of Bangladesh, Fisheries Resource Survey Systems Department of Fisheries, Dhaka, Bangladesh.
DoF. 1997. Summary of Year-wise Fish Production in Bangladesh Since 1961. Department of Fisheries, Dhaka, Bangladesh.
FAO. 1995. Review of the State of World Fishery Resources: Inland Capture Fisheries. FAO Fisheries Circular No. 885. FAO, Rome.
IDA. 1990. Staff Appraisal Report on Third Fisheries Project. The World Bank, International Development Agency. Washington, USA
Islam. M.Z. 1997. Enhancement of floodplain fisheries - Third Fisheries Project experience. National Workshop on Policy for Sustainable Inland Fisheries Management. ICLARM, DANIDA, IFAD, DoF. Dhaka, Bangladesh. (Abstract).
TFP. 1996. Implementation completion (floodplain stocking component). Third Fisheries Project. Department of Fisheries, Dhaka, Bangladesh.