Collaboration for Agriculture & Rural Development:" Development of clam culture for improvement and diversification of livelihoods of the poor coastal communities in Central Vietnam - MS2 " potx

Growth rate Width of M lyrata culture in Influent Pond, by Density Growth rate thickness of M.. Growth rate Thickness of M lyrata culture in Influent Pond, by Density Growth rate weigh

Ministry of Agriculture & Rural Development

CARD Project Progress Report

027/05VIE: Development of clam culture for

improvement and diversification of

livelihoods of the poor coastal communities

in Central Vietnam

MS2: First Six-Monthly Report

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 of North

Central Vietnam (ARSINC)

Vietnamese Project Team Leaders 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)

Completion date (original) February 2009

Completion date (revised)

Reporting period February 2006 – October 2006

In Australia: Administrative contact

Name: Position: Organisation

3.1 Project Implementation Progress

3 1.1 Key Highlights

• Technological and socioeconomic evaluation completed Report

submitted Report reviewed and accepted by CARD administration

• Clam culture in ponds (production) experiments involving prawn farm effluent and influent is progressing well

• Clam and prawn polyculture experiments is progressing well

• Preliminary experiments on clam spat production produced encouraging results

• Hatchery infrastructure established for spat production trials

3.1.2 Key outcome

a) Socio economic study completed

• Due to pollution as a result of poor water and nutrient management in the pond, shrimp culture is threatened with disease outbreaks Production cost is increasing

and profitability is being reduced due to the use of more chemicals, lime,

probiotic, etc for water and disease management

• Banks are reluctant to extend capital due to inconsistent aquaculture production due to unreliable culture technique in the case of clam culture Similarly banks are hesitant to provided loans for shrimp culture because of the high risk due to disease out break

• Lack of clam seed due to technology gaps is a major constraint, limiting the growth of clam farming development

• Although there is a ready market for clam, the middlemen exploit the farmer and generate a low price, which results in a low profit margin for the farmer Farmers indicated the need for cooperatives to play a major role in marketing

b) Production experiments made excellent progress Significant progress has been made

in this section Preliminary results from production experiment indicated that clam can be successfully cultured in ponds This is the very first successful production of clam in ponds carried out in Vietnam Although the experiment is still in progress, the

preliminary results indicated good clam growth and survival rate

C) Initial trials of spat production completed and encouraging results obtained

4 Introduction and Background

A summary of the project objective, outputs expected and approach and methodology

4.1 Objective

• The objectives of this project (027/05VIE) include the following:

• To develop and extend the clam culture technology (hatchery and

environment management using clam aquaculture to improve prawn farm effluent utilisation

4.2 Outputs Expected

In accordance with expected output proposed, the fist six months were focused on following aspects related to achieving the development of clam production

technology

and hatchery operational procedure

• Infrastructure establishment for clam production trials in ponds

• Construction of lab facilitates for spat production experiments

• Clam production in ponds started

• Initial experiments on spat production started

• Completion of Socioeconomic survey

Above mentioned activities were completed as per the proposed logfram

4.3 Methodology

Two visits by Australian Project Leader and scientists (one in April 2006 and the other August 2006) enabled to undertake major review of the project methodology, implementation strategy and resource and progress evaluation Scientific approach has been refined for implementing appropriate methodology for the experiments The advantages are:

• Incorporate information from preliminary research results into the

following experimental design

• Clear scientific comparisons are possible

• Avoid duplication of activities

• Ease of management

• Efficient use of resource

4.3.1 Summary for amendments and clarifications

• Clam culture experiments

a) It was decided to exclude the objective of determining optimum size from the first three experiments (Polyculture of Clam and Prawn, Clam culture in prawn farm

effluent, Clam culture in prawn farm influent) as this could be done in other two

experiments where objective of determining substrata will not be included The

experiments would instead now focus on the following two objectives:

i Determine suitable substrata

ii Determine optimum stocking density

b) Removal of Substrate Experimental Objective from the rotational clam culture in prawn farm and intertidal clam culture Experiment is recommended The Rotational Clam Culture experiment will instead focus on the following two objectives

i Determination of optimum size

ii Determination of optimum density

Rotational clam culture prawn has to wait until September 2006 During this period

of degree of risk, local support and collaboration, resource availability and degree of management difficulty Also the areas selected for the experiments are well known for

clam occurrence

d) Standardisation of sampling and measurement methods for all experiments to reduce data collection error was advised Due Standardisation of methods for measurement and use of measuring equipment, random sampling / sample selection from ponds, and rotational roster for data collection staff; Determination of sampling differences between staff was established

• Hatchery Experiments

Based on the preliminary results from the hatchery experiments the following sections

revised and refocused

i Brood Stock Conditioning

ii Breeding and Spawning techniques iii Larval Rearing / Culture Methods

iv Nursery (inclusive of Larval Settlement)

a) Experiments to determination of suitable temperature range for brood

stock conditioning will be further focused in the next experiment

b) Salinity Experiment to Hatchery Larvae Rearing Experiment A Salinity

Experiment to investigate the effect of salinity on growth and survival Each of 6 salinity concentrations between 10PPT and 35PPT were stocked with

25,000 larvae and measured for growth and survival rates until pediveliger

or late-umbo development stage (approximately 10 days)

c) Conduct of two larvae culture systems for comparison, in the larvae stocking density and water change component of the Larval Culture Experiment:

• Option one: the experiment will focus on larvae stocking density (with 3 level: 5 –

10 – 15 larvae/ml) with flow-through water system

• Option two: the experiment will focus on larvae stocking density (with 3 level: 5 –

10 – 15 larvae/ml) with water change every 24 hour, 36 hour and 48 hour

The two options were selected due to the need to determine the suitability of a single system for future experiments that would give a survival rate closer towards survival rates in literature

d) Introduction of a Nursery Experiment with the objective of determining optimal nursery conditions to maximize growth rate and survival rate of spat and juvenile of clam Specific objectives include:

• To determine feeding regime

• To determine optimum stocking density

• To determine optimum substrate (artificial bottom and solid bottom/nylon mesh only)

• To determine nursery type (comparison of the hatchery through system with floating raft in booming pond systems)

system/flow- • This experiment will be described in greater detail below

e) Nursery Experiment specifications were finalized and the specifications were as follows:

• Method: The clam spats in their first week after settlement will be

transferred to nylon meshed screens for grow out Different mesh size of screens will be used for grading the spats during growth out period Following two methods are

proposed for spat grow-out

• Option 1: Indoor flow-through system (consist of holding tanks with size of 0.6 x

1.2 x 2.4 m): Water with algae (food) from the blooming pond (algal pond) will be fed into holding tanks containing spats and then returned back to algal pond This

continuous feeding will be carried out using electric pump

• Option 2: Outdoor pond system: In this system, spats will be reared in

the floating rafts kept within the blooming pond Water quality in blooming pond will be managed by adopting strict pond fertilization regime and pond management measures including water levels may need to be controlled to make sure that there are enough algae for feeding spat during the nursing period

The experiment will be focused on the following parameters:

1 Substrate Screen substrate Screen substrate

Solid substrate Solid substrate

2 Stocking density 150g/m3 200g/m3 250g/3 150g/m3 200g/m3 250g/3

3 Selected species of Species Species Species

algal culture (plastic

bags)

During the experimental period water quality parameters such as oxygen (6-8 mg/l), pH (8-8.5), ammonia <0.2 mg/l and water flow rate (30 ml/minutes/g of spat) will be maintained Density (biomass) of spats considered for the

experiment are: 150g live weigh/m3, 200g live weigh/m3 and 250g live weigh/m3

(volume of tank units is 2 m3 with 10 screens holding)

The holding tanks will be drained and cleaned each every two days, in this time the spat holding screens be also cleaned

All treatments will be carried out in triplicates The growth and survival rate of spats will

be recorded weekly along with grading

5 Progresses to Date

5 1 Implementation Highlights

5.1.1 Socio-economic study

Initial phase socio economic study completed The report accepted after the review

profitable despite a low production rate However, clam culture has the disadvantage of mainly relying on capture of seed source from the wild At the same time, due to

disease outbreak in the prawn farming sector as a consequence of water deterioration, there has been an overall reduction in aquaculture production Clam is recognized as a water cleaning machine(filter feeder), thus water quality will be improved if clam can be incorporated into the shrimp farming system Therefore integrated clam and shrimp culture would reduce risk through better pond water quality management, and has the potential to improve shrimp and clam production

Banks are reluctant to provide capital funds to the clam industry due to

inconsistent production and unreliable technology The shrimp farming sector

suffers a similar fate because of it’s high risk due to disease outbreak

Currently the clam industry is restricted to tidal flats In order for the clam industry to grow, clam technology for ponds must be developed, as there are limited tidal flats available for clam culture

Farmers received low prices for clam due to exploitation by middle men Cooperatives need to play a major role in marketing the clams

Shrimp and clam culture systems are seen as the backbone of the coastal community Clam culture is making more profit than shrimp, due to less capital cost and reduced risk It’s successful expansion will definitely improve the family income and living

standards for the people in the provinces

• Key Results

a) Technology Issues

• Lack of Seed

• Lack of Clam Culture Method

• Lack of technical information

• Lack of information on species

• Lack of information on Polyculture of Clam and Prawn

b) Social factors

• Suitable education level of farmers (>88% secondary and above education) • High levels of attendance of aquaculture training (86%)

c) Economic Issues

• Finances from Banks and other Lending Institutions

• Funding from the Vietnamese Government

• Middlemen Margin Affecting Profits

• No Support Role by Cooperatives

• Key outcomes and Recommendations

• Clam culture can act to remediate the impacts of prawn farming so as to

increase sustainability of prawn farming in Vietnam

b) Recommendations

• Should develop hatchery technology

• Should develop grow-out and production technology

• Development of a business model to enable implementation by farmers

• Cooperatives and government should help in the marketing of Clam culture and Clam consumption

5.1.2 Production Experiment

Establishment of infrastructure and part of the results were included in this

section Experiments are in progress and complete results will be reported in

the next report

5.1.2.1 Infrastructure

a) Effluent and Influent pond systems set up in Thanh Hoa

An effluent system for two treatments – bottom treatment, there are 9 ponds for 3

triplicates of substrata such as sand bottom, clay-sand bottom and clay bottom and

Density treatment, there are 9 ponds for 3 triplicates of density levels (90clams/m2,

120clams/m2 and 150clams/m2 ) comprised of a total of eighteen 9m2 ponds were set up

in Thanh Hoa Province (Fig 1) An influent system built (similar to effluent) and

experiments is being conduced the same as treatment included in effluent (Fig 2)

b) Clam and prawn polyculture An polyculture system for one treatment – Density

treatment: there are nine 50m2 ponds for 3 triplicates of density levels such as

60clams/m2, 90clams/m2 and 120clams/m2 This experiment also set up in Thanh Hoa Province

Fig 3 Density – Influent / Effluent System: project staffs are checking growth rate of clam

in pond

.c) Results obtained so far Since this experiment is in progress, results presented here only up to September 2006 Analysis will be undertaken after the completion of the

experiments A comprehensive analysis and discussion and conclusion will be included

in the next report

Fig 4 Clam samples from the pond culture

• Density Experiment Growth Rate

During the initial phase of the experiments (when animal size is relatively small) the

growth rate appears to be similar in all three density treatments However, the growth difference became prominent as animal grow bigger Final data analysis and the results will be discussed in the next report This experiment is not yet completed

Figure 5 A to 5D show result of clam growth rate from influent pond system with

different stocking density

Growth rate (height) of M lyrata culture in influent pond by

Density Size of clam (in mm)

22.00 21.00 20.00 19.00 18.00 17.00 16.00 15.00

Days to culture

Figure 5 A Growth rate (Height) of M lyrata culture in Influent Pond, by Density

fluent pond by Density

0 15304560

Days to culture

Figure 5 B Growth rate (Width) of M lyrata culture in Influent Pond, by Density

Growth rate (thickness) of M lyrata culture in influent pond by Density

Days to culture

Figure 5C Growth rate (Thickness) of M lyrata culture in Influent Pond, by Density

Growth rate (weight) of M lyrata culture in influent pond by Density

0 15304560

Days to culture

Figure 5 D Growth rate (Weight) of M lyrata culture in Influent Pond, by

Density Figure 6A to 6D show result of clam growth rate from influent pond system with different substrate

Growth rate (height) of M lyrata culture in

influent pond, by Substrate

0 15304560

Days to culture

Figure 6 A.Growth rate (Height) of M lyrata culture in Influent Pond, by Substrate

Growth rate (width) of M lyrata culture in influent pond, by Substrate

0 15304560

Days to culture

Figure 6 B Growth rate (Width) of M lyrata culture in Influent Pond, by Substrate

Growth rate (thickness) of M lyrata culture in influent pond, by Substrate

0 15304560

Days to culture

Figure 6 C Growth rate (Thickness) of M lyrata culture in Influent Pond, by Substrate

Growth rate (weight) of M lyrata culture in

influent pond, by Substrate

Days to culture

Figure 6 D Growth rate (Weight) of M lyrata culture in Influent Pond, by

Substrate

Figure 7A to 7D show result of clam growth rate from effluent pond system with

different stocking density

Growth rate (height)of M lyrata culture in

effluent pond, by Density

0 15304560

Days to culture

Figure.7A Growth rate (Weight) of M lyrata culture in effluent Pond, by Density

Growth rate (width)of M lyrata culture in effluent pond, by Density

0 15304560

Days to culture

Figure.7B Growth rate (Width) of M.lyrata culture in effluent pond, by Density

Growth rate (thickness) of M lyrata in effluent

Growth rate (weight) of M lyrata culture in effluent pond, by Density

Grow rate (height) of M lyrata culture in

effluent pond, by Subtrate

0 153045 60

Days to culture

Figure.8A.Growth rate (height) of M lyrata in effluent Pond, by

Substrate

Development of clam culture for improvement and diversification of livelihoods of the

poor coastal communities in Central Vietnam

Growth rate (width) of M.lyrata culture in

effluent pond, by Substrate

0 153045 60

Days to culture

Figure 8B.Growth rate (width) of M lyrata in effluent Pond, by Substrate

Growth rate (thickness) of M.lyrata culture in effluent pond, by Sustrate

0 153045 60

Days to culture

Figure 8C Growth rate (thickness) of M lyrata in effluent Pond, by substrate

Grwoth rate (weight) of M.lyrata culture in effluent pond, by Substrate

5.1.3.1 Brood stock Conditioning

a) Infrastructure establishment

A triplicate system for two treatments – Sand bottom and Solid bottom was set up at ARSINC This comprised of a total of six 200L tanks in a recirculation system at

28.25°C

Fig 9 : Recirculation System (Constant Temperature) at ARSINC

A triplicate system for two treatments – Sand bottom and Solid bottom was set up at ARSINC This comprised of a total of six 400L tanks in a recirculation system with an automated heating system to increase the temperature from 26°C to 30.5°C

b) Conditioning methods

Gonad Development using stable temperature and gradually increasing temperature procedures were used in brood stock conditioning experiments The experiment

conducted in a stable temperature system, water temperature was constant at

28.250C in 10 days The experiment conducted in a Increasing temperature system,

water temperature was increasing from 260C up to 30,50C in 10 days

c) Key Results

Figure 11 and 12 show the status of gonad development in two experimental conditions

In stable experimental condition figure 11 shows that gonad of clam is developing at Stage but the development of egg cells is not uniformly progressing Fig 12 (increasing temperature) also shows that gonad of clam is developing at stage IV but the

development of egg cells is not uniformly progressing

Fig 11 gonad development under stable temperature 28.250C

Fig 12 Gonad development under increasing temperature 260C to 300C

• Stable Temperature Experiment

Minimum gonad development was observed for both the sand and solid bottom experiments at 28.5°C (Figure 11) An average overall decrease in gonad weight of 0.12g was observed for sand bottom stable temperature treatment and a decrease of 0.19g was observed for solid bottom treatment

There was no significant variation in soft weight of the samples, with a maximum variation of +/- 0.53g in the sand bottom treatment and a maximum variation of +/- 0.19g for solid bottom stable temperature treatment

Gonad Development of Clam (M.lyrata ) in Stable Temperature System

Weight (in gram) 2.5

T imes (in Days) to check Gonad Development

Figure 13 M lyrata Gonad Development at Stable Temperature, Sand and Solid

Bottom (Breeder Conditioning in Hatchery Experiment)

• Increasing Temperature Experiment

In random sampling of sand bottom and solid bottom environments for Increasing

Temperature treatments (26°C to 30.5°C), 15 samples were taken from each

environment per sampling Total weight (including shell), soft weight and gonad

weights were measured for variations in grams to two decimal places Similar to the previous experiment, an increase in ‘soft weight’ would correspond to gonad

development (Kraeuter and Castagna, 2001) An average overall decrease in soft

weight of 0.47g was observed for sand bottom and a decrease of 0.40g was observed for solid bottom

No gonad development was observed for both the sand and solid bottom experiments for the range of 26°C to 30.5°C (Figure 14) An average overall decrease in gonad weight of 0.12g was observed for sand bottom stable temperature treatment and a decrease of 0.19g was observed for solid bottom treatment

There was no significant variation in soft weight of the samples, with a maximum

variation of +/- 0.53g in the sand bottom treatment and a maximum variation of +/- 0.19g for solid bottom stable temperature treatment

Gonad Development of Clam (M.lyrata ) in Increas ing Temperature System