Ministry of Agriculture & Rural Development Collaboration for Agriculture & Rural Development (CARD) 027/05VIE Development of clam culture for improvement and diversification of livelihoods of the poor coastal communities in Central Vietnam MS04: 3 rd Six-Monthly Report April – October, 2007 1 Table of Contents 1. Institute Information 3 2. Project Abstract 4 3. Executive Summary 4 4. Introduction & Background 6 5. Progress to Date 6 5.1 Implementation Highlights 6 5.1.1 Clam production (Grow-out trials) 6 5.1.2 Hatchery production 8 5.1.3 Propagation of the technologies (on farm trials level) 16 5.2 Smallholder Benefits 16 5.2.1 Opportunity to utilize the brackish water ponds for clam production 16 5.2.2 Increasing in production and benefit from clam culture in the intertidal areas 16 5.2.3 Easily Applicable Farming Knowledge 16 5.2.4 Low Investment Risk 16 5.2.5 Maximizing Commercial Potential through Knowledge 16 5.3 Capacity Building 17 5.3.1 ARSINC 17 5.3.2 End-users 18 5.3.3 Enhanced reputation and relation ship with other institutions and collaborators 18 5.4 Publicity 18 5.5 Project Management 18 6. Report on Cross-Cutting Issues 18 6.1 Environment 18 6.2 Gender and Social Issues 19 7. Implementation & Sustainability Issues 19 7.1 Issues and Constraints 19 7.2 Options 19 7.3 Sustainability 19 8. Next Critical Steps 19 9. Conclusion 19 10. Statuatory Declaration 20 2 1. Institute Information Project Name Development of clam culture for improvement and diversification of livelihoods of the poor coastal communities in Central Vietnam. (Project No: 027/05VIE) Vietnamese Institution Aquaculture Research Sub-Institution for North Central (ARSINC) Vietnamese Project Team Leader Mr. Nhu Van Can (Project Director) Mr. Chu Chi Thiet (Project Manager) Australian Organisation South Australian Research and Development Institution (SARDI) Australian Personnel Dr Martin S Kumar (Team Leader) Dr Bennan Chen (Senior Scientist) Date commenced February 2006 Completion date (original) February 2009 Completion date (revised) Reporting period November 2006, April 2007 Contact Officer(s) In Australia: Team Leader Name: Dr Martin Kumar Telephone: 08 82075 400 Position: Principal Scientist, and Program Leader, Integrated Biosystems Integrated Resource Management and Biotechnology Fax: 08 82075481 Organisation South Australian Research and Development Institution (SARDI) Email: kumar.martin@saug ov.sa.gov.au In Australia: Administrative contact Name: Telephone: Position: Fax: Organisation Email: In Vietnam Name: Nhu Van Can Telephone: +84.383829884 Position: Director Fax: +84.383829378 Organisation Aquaculture Research Institute for North-Central Email: arsinc@vnn.vn 3 2. Project Abstract 3. Executive Summary The. • The stocking biomass of 2 ton/ha is recommended for optimising cost benefits in clam production under intertidal culture conditions. • Successful production of clam as a rotational crop in prawn farms provides new opportunity for the farmers to utilise the prawn farm which normally used only for 4 months per year for shrimp culture. • Artificial conditioning of clam brood stock has been successfully completed • The mass production of 2 million spat was achieved under revised larval rearing procedure developed. The main objective of the project is to develop and extend the clam culture technology (hatchery and husbandry) to sustain livelihoods of poor coastal farmers in the North Central provinces and to develop a strategy which contributes to sustainable aquatic environment management using clam aquaculture to improve prawn farm effluent utilisation. In the first half of the second year, two types of clam production trials (intertidal clam production, clam production in prawn ponds as rotational crop) and broodstock conditioning trials have been successfully completed. Details of the both production trials along with brood stock conditioning results are included in this report. Key findings are listed below. 4 3.1 Project Implementation Progress 3. 1.1 Key Highlights Project progressed well during the last 18 months and achieved specified milestones related to the technology development in clam husbandry (production) and hatchery areas. Following milestone reports submitted were reviewed and accepted. • Socio-economic evaluation report • 1 st six monthly report • 2 nd six monthly report In the first half of the second year, two clam production trials including; intertidal clam production, clam production in prawn ponds as rotational crop, broodstock conditioning have been successfully completed. Details of the both production trials along with brood stock conditioning results are included in this report. A farmer selection criterion was developed in consultation with lead farmers, village representatives and provincial authorities. The details will be reported in the next 4 th six monthly report. In the second year, the work will be concentrated on farm trials, which fine tune the technology and facilitate formulation of extension manuals. In the third year, work will focus on extension of technology including expanded farmer participated trials. Project impact will also be assessed during the third year 3.1.2 Key outcome a) Production experiments made excellent progress • Optimisation parameters for intertidal clam production have been determined. The stocking biomass of 2 ton/ha is recommended for optimising cost benefits in clam production under intertidal culture conditions. • Viability of clam production in prawn pond as a rotational crop has been established. Successful production of clam as a rotational crop in prawn farms provides new opportunity for the farmers to utilise the prawn farm which normally used only for 4 months per year for shrimp culture. b) Hatchery production experiments. Based on the results of initial larval rearing experiments, a second mass spat production trials successfully completed by producing 2 million spats. Artificial conditioning of clam brood stock has been successfully completed Experimental design on larval rearing and nursery production has been revised based on this trial results. Larval rearing and brood stock conditioning experiments are in progress. c) On farm trials/Demonstration. An introductory workshop on clam culture has been conducted for the farmers in the North Central Provinces. Farmer selection criteria for demonstration were prepared. Lead farmers were selected. Trials are under way. Further workshops are being organised to provide guidelines on demonstration trials to farmers. Overall the project is progressing well as per the proposal. 5 4. Introduction & Background The main objective is to develop and extend the clam culture technology (hatchery and husbandry) to sustain livelihoods of poor coastal farmers in the North Central provinces; and to develop a strategy which contributes to sustainable aquatic environment management using clam aquaculture to improve prawn farm effluent utilisation. The aims of the proposed project are: a) to provide poor fisher community an alternative income, food security; b) to improve technological and extension capacity for the stakeholders; and c) to reduce negative impacts of shrimp culture through implementation of a strategy for environmental management and waste utilisation of existing resources. 4.1. Specific objectives: The objectives of this project (027/05VIE) include the following: • to develop and extend the clam culture technology (hatchery and husbandry); • to sustain livelihoods of poor coastal farmers in the North Central provinces; and • to develop a strategy which contributes to sustainable aquatic environment management using clam aquaculture to improve prawn farm effluent utilization. 4.2. Outputs Expected In accordance with expected output proposed, the last six months were focused on following aspects related on the following - Completed intertidal clam production trial - Completed rotational clam in prawn farm - One set of mass production trials completed, Larval rearing experiments to optimize the larval survival and growth is in progress. - Brooder conditioning experiments completed - Farmer selection criteria for demonstration was developed 4.3. Methodology The visits by Australian Project Leader in April 2007 enabled to undertake major review of the results obtained on clam production and larval rearing trials and also enabled to fine tune the experimental procedure for larval rearing and nursery production optimization. Team workshop was organised in April enable to evaluate the clam production results and larval rearing methods. Larval rearing and nursery productions experiments were revised and the trials are in progress. Demonstration trials, design, planning, farmer selection criteria and execution procedures were finalised. 5. Progress to Date 5.1 Implementation Highlights 5.1.1 Clam production (Grow-out trials) The research in pond culture type will be focused on suitability of substrate, optimum stocking density, and stocking size. All experiments were conducted in triplicate. The outcome of the experiments (culture types) will be used for the development of technical 6 guidelines for on farm trials in the second year. The clam production involved the following 5 types culture trials: a) Clam culture using prawn farm influent water (reservoir): Clam culture was carried out as a pre- treatment for water intake in prawn farm. Work completed and the results reported b) Clam culture using prawn farm effluent (effluent treatment pond). Clam culture was conducted by utilising prawn farm effluent. Work completed and the results reported. c) Shrimp and clam polyculture: Simultaneous culture of prawn and clams was undertaken with a view to improve farm water quality as well as generate additional income. Work completed and the results reported. d) Alternative/rotation crop: Clam culture was under taken after the pawn harvest as rotational crop. Work completed and results included in this report. e) Clam culture in intertidal area: Inter tidal area was used for clam culture. Work completed and the results included in this report. 5.1.1.1 Experiment on clamcultured in the intertidal areas Traditional clam culture has been undertaken in the inter-tidal areas. The aim of this experiment was to enhance the profitability of clam farmer. The key objective was to increase productivity and benefit by determining the optimum stocking density and stocking size. The other parameters within the culture system can not be altered as it is a natural ecosystem highly connected to capture fisheries which is one of the key industry for the fisher community. Materials and method The inter-tidal clam culture experiment was undertaken in 24 plots of 50 m 2 each for 8 treatments (3 replicates each). The small size of clam seed (1.0 cm) were stocked at 4 different stocking biomass 0.5, 1.0, 2.0 and 3.0 tons/ha and referred as T1, T2, T3 and T4 respectively. The bigger size of clam seed (1.7 cm) were stocked at 4 different stocking biomass of 3.4, 6.8, 13.6 and 20.6 ton/ha and referred as T5, T6, T7 and T8 respectively (the densities were adjusted due to actual stocking size availability). Experiment was terminated after 165 days rearing. The environment factors such as temperature, DO, pH and turbidity , salinity of water in the experiment site were monitored daily at 3 designated points within the experimental area while samples of water were analysed weekly for Total N, Total P, Ammonia and Nitrate. Growth of clam, expressed in mean of height (cm) and mean of weight (gr), was determined by random sampling (n=30) and measured every fortnight. The daily specific growth rate (SGR) was calculated using the following formula: SGR(%/day) = 100*(LnW f -LnW i )/t Where: W i and W f are mean of initial weight and final weight, respectively and t is number of experiment days. The final production (expressed as ton/ha) of each treatment was conducted by entirely harvested and the biomass gained was calculated from final production minus the stocking biomass. Size variation was evaluated according to (Wang et al., 1998) in which the mean of three replicates of the coefficient of variation (CV) was used to examine the inter-individual 7 weight variation among the clam in each treatment: CV(%)=100*SD/ M where M is mean of weight and SD is standard deviation of the clam in each treatment. The meat ratio (% of meat weight/ total weight) of clam estimated to understand meat yield. This parameter was measured by random sampling of clam and the total weight of the clam and meat weight was measured by separating the meat content. The excess water was removed by putting the sample on tissue papers. The fatty acids content of clam was determined from random samples, preserved in Liquid Nitrogen Biological Container (YDS-3, -196 o C). The samples then were analysed by extracting the fatty acid in methanol/toluene mixture (3:2 v/v) and analysed in Finnigan Trace GC untra, capilary collume BP-70 (50m x 0.32mm x 0.25µm) in the Laboratory of Vienamese Academy of Science and Technology. All data of the treatments were tested for significant differences (p<0.05 or p<0.01) using One-way ANOVA followed by Turky test for multiple comparisons of means. The data are expressed as Average ± SD and statistical analyzed was performed using GraphPad Prism version 4.0 and Microsoft Office EXCEL for Window. Results and discussions 1.1 The environment conditions of the experiments The experimental site in the intertidal area is situated in Hau Loc District, Thanh Hoa Province near the estuary where clam naturally occurred. The environment conditions such as DO, water temperature, pH and salinity (table 1) are regarded as the best conditions for clam development. The high levels of salinity fluctuation are typical for estuary ecological conditions. This means clam are not be affected by the marked variation in the salinity and good growth and survival rate noticed. The average water temperature was 23.59±2.40 o C s. Table 1. Environment conditions in the cultured areas Paramenters DO (ppm) Water temperature ( o C) pH Salinity (ppt) Turbidity (cm) Aver 6.25±0.42 23.59±2.40 25.65±2.84 9.05±3.13 Max 7.66 31.00 8.99 31.00 20.00 Min 5.50 19.50 7.21 20.00 5.00 1.2 Growth performance The growth performance of the two stocking sizes of clam at different stocking biomass expressed in specific growth rate, final length and final weight are shown in the table 2 and table 3. Table 2. Growth performance of clam at stocking size of 1.0cm Treatments T1 T2 T3 T4 SGR 1.25±0.05 a 1.13±0.05 a 1.08±0.10 ab 0.94±0.37 b Final length (cm) 2.04±0.13 a 2.01±0.09 ab 1.95±0.10 b 1.95±0.11 b Final weight (gr) 5.92±1.08 a 5.76±0.81 ab 5.46±0.76 ab 5.30±0.85 b % of meat/total weight 15.87±1.00 a 15.48±2.72 a 15.53±1.02 a 15.15±5.47 a CV% (weight) 28.72±2.55 a 23.07±0.24 b 23.73±1.55 b 27.78±2.11 ab Value (Mean±SD) followed by different superscript letters within a row are significantly different (P<0.05). T1, T2, T3, T4 are treatments of clam cultured at 0.5, 1.0, 2.0 and 3.0 tons/ha respectively. SGR = daily specific growth rate; CV = coeficient of variation 8 9 For the small size of clam (1.0cm), there was no significant difference in specific growth rate among T1, T2 and T3 treatments (table 2) indicating that growth of the clam was not be affected by the stocking biomass below 2 tons/ha. The final size of clam was more variable at low (T1) and high (T4) levels of stocking density compared to the medium ones. The meat yield expressed in percentage of meat per total weight, which regarded as the most valuable part of clam was not significant different (p>0.05) in all treatments. Table 3. Growth performance of clam at stocking size of 1.7cm Treatments T5 T6 T7 T8 SGR 0.62±0.04 a 0.46±0.03 b 0.33±0.02 c 0.32±0.02 cd Final length (mm) 2.36±0.17 ab 2.40±0.10 a 2.32±0.11 bc 2.27±0.10 c Final weight (gr) 9.24±1.20 a 9.33±0.95 a 8.90±1.12 a 8.21±1.01 b % of meat/total weight 14.53±1.89 a 15.78±2.35 a 16.53±0.62 a 15.48±1.31 a CV% (weight) 22.3±0.45 a 19.05±5.16 a 18.69±3.36 a 22.73±4.16 a Value (Mean±SD) followed by different superscript letters within a row are significantly different (P<0.05). T5, T6, T7 and T8 are treatments of clam cultured at 3.4, 6.8, 13.6 and 20.6 ton/ha respectively. SGR = daily specific growth rate; CV = coeficient of variation The growth performances of 1.7 cm clam stocked at different densities are provided in table 3. In the case of 1.7 cm clams, the increase in stocking biomass significantly impacted specific growth rate. At the stocking density higher than 3 tonnes/hectre, the SGR was relatively low and was not significantly different for T7 and T8 treatments. The final length and final weight of the T8 treatment were significantly smaller than the other treatments. Generally, at younger stage, animal grow at a faster rate. In the case of clam, the small size (1 cm) the growth was significantly better than the bigger size (1.7cm) if stocked at same biomass. In the intertidal areas, the natural feed and environmental factors are uncontrollable and are dependent of nature. Dynamics of tide, wave and current create the availability of algae, organic matter that regarded as feed for clam. However, clam is a filter feeder and passively dwells on the bottom therefore, increase in biomass beyond certain level, the natural feed might not be enough for growing. Results of growing performance (table 3) indicated that at high stocking biomass (3 ton/ha), the growing could be inhibited as it was evidenced that the grow rate was significantly reduced as in creasing of stocking biomass. It also is noted that the culture period is winter time of the year when water temperature normally is low and not appropriate for growing of M. lyrata, the tropical species. 1.3 Survival The stocking biomass impacted the survival rate in both sizes of clams stocked. Survival was very high in the low stocking biomass and was almost similar in the treatment T2 and T3. The survival rate in T1 and T4 treatment was significant different (P<0.05). In the bigger size groups, the T7 and T8 treatments resulted in very low survival and not significant different compared to the treatment T5 and T6. The environmental condition and food availability could be attributed as main reason for the impact stocking biomass on survival rate. T1 T2 T3 T4 50 60 70 80 90 100 110 a ab ab b Clam at stocking size of 1.0 cm Survival (%) T5 T6 T7 T8 50 60 70 80 90 100 110 a b c c Clam at stocking size of 1.7 cm Survival (%) Fig 1. Survival of clam size 1.0cm and 1.7cm rearing at different stocking biomass. Valu , T3 1.4 Production and quality ated from both growth and survival. There was a positive T3 T4 e (Average ± S.D) followed by different superscript letters are significantly different (P<0.05). T1, T2 and T4 are treatments of clam cultured at 0.5, 1.0, 2.0 and 3.0 tons/ha respectively; T5, T6, T7 and T8 are treatments of clam size 1.7cm cultured at 3.4, 6.8, 13.6 and 20.6 ton/ha respectively. The production of clam was estim relation noted on clam production and stocking biomass although the growth and survival were negatively affected. Among the small stocking size group, the final production increased accordingly with the increase stocking biomass and no significant difference (P>0.05) was detected between T1 and T2 nor T3 and T4. However, T1&T2 were significantly different in final production compared to T2 & T3. The percentage of biomass gained, in contrast, was showing reduction trend when increasing the stocking biomass and no significant difference between T1 and T4 was detected. This is due the fact that the increase in biomass negatively affected the growth and survival of the clams. Table 4. Biomass production of clam at stocking size of 1.0cm Treatments T1 T2 Final production (ton/ha) 4.14±0.57 a 6.82±0.56 a 12.62±2.16 b 14.84±0.91 b Biomass gained (ton/ha) 3.62±0.57 a 5.78±0.56 a 10.54±2.16 b 11.72±0.91 b % of biomass gained 6 5 5 97.1±109.4 a 55.8±53.6 ab 06.9±104.0 ab 375.8±29.3 b Value (Mean±SD) followed by differen letters with fferen were significantly mass production of clam at stocking size of 1.7cm T7 T8 t superscript in a row are significantly di t (P<0.05). T1, T2, T3 and T4 are treatments of clam cultured at 0.5, 1.0, 2.0 and 3.0 tons/ha respectively In the bigger stocking size (1.7cm), the final production in the treatments increased as increase in stocking biomass (p<0.05) while the biomass gained was not significant different (p>0.05) in the treatment T5 and T6. The percentage of biomass gained, in contrast, was reduced as increasing of stocking biomass in T5, T6 and T7. However, the treatments T7 and T8 were not significantly different in terms biomass gained during the experimental period. In both sizes the increase in biomass certainly impacted net production negatively. Table 5. Bio Treatments T5 T6 Final production (ton/ha) 9.49±0.68 a 14.46±0.69 b 23.58±0.68 c 34.80±1.00 d Biomass gained (ton/ha) 6.10±0.68 a 7.68±0.69 a 10.02±0.69 b 14.46±0.99 c % of biomass gained 180.0±20.0 a 113.3±10.1 b 73.9±5.1 c 71.1±4.8 c 1 [...]... availability in ponds was not the factor that limited the clam quality The presence of the number of fatty acids detected in this clam compared to those in the clam cultured in the intertidal area indicated that clam cultured in pond were not different in terms of quality as food for human consumption Table 12 Fatty acids of clam cultured at different stocking sizes and different stocking biomass in the rotational... Clam aquaculture in Vietnam, is a family or household activity Women undertake 5 0-6 0% of the work including husbandry, harvesting and marketing Therefore, aquaculture activities are very much a household duty If the proposed project is properly implemented through making relevant information more available and improving the skills of the information deliverers, the results will significantly increase... Feeding frequency was 4 times in 24 hours (6h, 11h, 16h, 21h) - The salinity was maintained at 25ppt during conditioning period, the bottoms of tanks were provided with sandy substrate B Spawning method - The matured brooders were transferred to spawning tank for the spawning The male and female were kept together in the same spawning tank (200 lit) with density at 150 clams per 200 litter tanks - The. .. T3 and T4 are treatments of clam cultured at 0.5, 1.0, 2.0 and 3.0 tons/ha respectively The The main cost in clam culture is the expenditure in seed purchase Cost of seed ranged between 46% to 81% in small size seed (1cm) for the four treatments ( T1, T2 T3 &T4) As all other costs are fixed the increase in stocking biomass increased the cost Although total production increased with the increase in. .. utilisation/treatment and simultaneous production of clams Developed method for prawn farm influent pre-treatment and simultaneous production of clams Developed clam culture technique in the intertidal area Performance Indicator Appropriate stocking size and density determined Suitable stocking size, density and substrate determined for each culture types Means of Verification At least each province and each culture. .. hatchery technical procedure and management • Training of two ASINC technicians o Live feed o Data processing and management Clam culture in the inter-tidal area Prawn and Clam (poly culture Effluent + clam culture Reservoir culture Hatchery manual prepared Training conducted Manual submitted Implementing Report submitted Development of skilled human resources Development of skilled human resources Development. .. cultured in the intertidal areas is showed in the table 6 and table 7 The net profit estimated based on the output cost and input cost and value/price of clam 3 Table 6 Economical evaluation of clam rearing at stocking size of 1.0cm Treatments Input Seed cost (35.000 VND/kg) Mesh and fencing (VND/ha) Labour cost for protection, cleaning (6monthsx1.200.000 VND/m) Hut for daily monitoring (VND/hut) Land lease... contribution in terms of income and food and therefore their importance and self esteem The Technological and socioeconomic study conducted by project team indicated that farmers received low prices for clam due to exploitation by middle men Cooperatives need to play a major role in marketing the clams Study further confirmed that shrimp and clam culture systems are seen as the backbone of the coastal community... personnel inputs have been delivered and the equipment and services identified above provided has been handed over to the Lead Vietnamese Institution Separate sheet attached 22 23 APPENDIX A - Project Progress against Proposed Objectives, Outputs, Activities and Inputs Project Title: Vietnamese Implementing Institution: Development of clam culture for improvement and diversification of Aquaculture Research... variation among the clam in each treatment: CV(%)=100*SD/ M where M is mean of weight and SD is standard deviation of the clam in each treatment The meat ratio (% of meat weight/ total weight) of clam in this experiment was evaluated to determine meat yield The total weight and the weight of meat (separating the meat from the shell) measured from the randomly selected samples All data of the treatments . 2 1. Institute Information Project Name Development of clam culture for improvement and diversification of livelihoods of the poor coastal communities in Central Vietnam. (Project No:. (027/05VIE) include the following: • to develop and extend the clam culture technology (hatchery and husbandry); • to sustain livelihoods of poor coastal farmers in the North Central provinces; and. the difference in the ammonia level in the ponds of the two treatments. Survival and grow performance of the clam Table 11. Survival and growth performance of clam in the rotational pond cultures