Aquaculture 1x2u60

INTRODUCTION TO AQUACULTURE

Definition of Aquaculture Aquaculture means; cultivation of the natural products of water such as fish, shellfish, crustaceans and plants under control conditions.

INTRODUCTION • •

•

The term aquaculture involves all forms of aquatic animals and plants in fresh, brackish and saltwater. In PNG, aquaculture's potential is highly regarded because it can complement wild fishery, provide for food security, especially in the central highlands. It has potential to be a great revenue earner for the nation; however production is limited to a number of species such as trout, carp and tilapia and recently pearl oyster, barramundi and marine prawns. In the last decade there has been rapid progress from the freshwater culture tilapia to Mariculture of barramundi, marine prawns and pearl oysters. Despite this the aquaculture development in PNG is constrained by poor coordination of research and development efforts, poor access to information and technology and chronic shortage for local aquaculture expertise.

SPECIES BACKGROUND • •

•

•

In 1960s, the freshwater fish farming began in PNG. Rainbow Trout (Oncorhynchus mykiss)was also introduced to PNG. –water temperature of 13˚C to 17˚C. Common carp (Cyprinus carpio) were introduced to PNG.Adaptable to harsh environment, disease resistance, omnivorous diet and fast grow. H2O 18˚C and distributed in both PNG Highlands and Lowlands. The tilapia (Oreochomis) have good characteristics for fish farming. They are fast growing and able to survive in poor water

cont`d…. •

The water temperature range for optimal growth and reproduction is between 20 and 30°C. Water temperatures as low as 12˚C a tolerated but water temperature below 10˚C a survived for prolonged period of time.

Parameters favorable for tilapia growth. Parameter Temperature

Level 25-30oc

comment Optimum for reproduction and growth Minimum for optimum growth Favor growth

DO (mg/L)

3

Salinity (ppt)

10-15

pH

6.5-9

CO2 (mg/L)

20

Total ammonia (mg/L)

0.02-0.5

Turbidity

30-35

Silt can damage

Water current

20

For intensive culture flow through system

Optimum for primary reproduction

Disadvantages of tilapia 1. Uncontrolled breeding in the ponds can lead to

overcrowding and stunted growth. They will not grow well if the water temperature is lower than 22˚C. Note: In all aspects of live, there are factors which have great effect on the species growth and reproduction for both internally and externally. Environmental factors and water quality adversely affects the growing and reproducing of the fish.

Water Quality There are two most important factors which determine the quality of water. 1. Temperature 2. Amount of oxygen dissolved in the water.

Temperature will affect all chemical& biological processes. Relationship

between growth and temperature.

Factors affecting the

species growth.

Fish nutrition There are two types; 1. Naturally produced food :- algae (phytoplankton)

and tiny animals (zooplankton) produced in the pond itself which can be increased by fertilizing the pond.

Fish nutrition 2. Supplement Food:-local waste products can be used as supplementary fish food. (broken rice, cereals, maize meals, fruits and vegetables, soybean etc.

Slides continue

Formulated feed for fish Fishmeal

Feeding guidelines for fish  Feed the fish at the same time in one corner of the pond. Fish will get

used to this and come near the surface of the water so it is easier to see if the fish are eating and growing well. Feeding should be done in the late morning or early afternoon when dissolved oxygen levels are high so the fish have enough time to recover from the high oxygendemanding feeding activity before nightfall  Do not over feed the fish. Too much food will decay and used up too much oxygen in the pond.  Do not feed fish in overcast day. Feed fish when the weather is fine.  Stop feeding fish for at least one day before breeding, harvesting or transporting them. This enables the fish to digest the food completely. In general, fry can be starved for 24 hours, fingerlings for 48 hours and adult fish to excrete waste making the water turbid.

Pond culture Good culture pond. Location

Select land with a gentle slope and layout ponds to take advantages of existing land contours. Construction Ponds may be dug into the ground, they may be partly above and partly in the ground, or they may be below original ground level; slopes and bottom should be well packed during construction to prevent erosion and seepage; soil should contain a minimum of 25% clay, rocks, grass, branches and other undesirable objects should be eliminated from the dikes

Pond depth

Depth should be 0.5- 1.0 m at shallow end, sloping to 1.5-2.0 m at the drain end; deeper ponds may be required in the lowland where temperature is very high.

Configuratio n Side Slopes

Best shape for ponds is rectangular or square

Drain

Gate valves, baffle boards or tilt-over standpipes should be provided.

Inflow lines

Inflow lines should be of sufficient capacity to fill each pond on within 3days; if surface water is used, incoming water should be filtered to remove undesirable plants or animals.

Total water volume

Sufficient water should be available to fill all ponds on the farm within a few weeks and to keep them full throughout the growing season.

Construct ponds with 2:1 or 3:1 slopes on all sides

Dikes

Dikes should be sufficient wide to mow; road dikes should be made of gravel; grass should be planted on all dikes.

Orientation

Situate ponds properly to take advantage of water mixing by the wind, or in areas where wind causes extensive wave erosion of dikes, place long sides of pond at right angles to the prevailing wind; use hedge or tree wind breaks when necessary.

Square pond

4 by 4; 1m shallow end

Circular pond Very hard for management.

Problems with earthen ponds • • • • • • • • •

Feed sinked in the pond resulted rise in bottom ground. Break top ground into the ponds. Dry season dries the ground water 2.5-3m deep ponds Tall grasses (bushy) Low pH of the soil Densely algae growth High turbidity Chemical deposition.

Questions to ASK?...?.....? What types of ponds do we have? How many ponds do we have? Am I progressing or dreaming? Am I helping myself or expecting miracles to happen to me? 5. How will I be improve on my farm work 6. How will I become VERY reliable person ? 7. When will I improve on my farm? 8. Where will I get help? 9. What is lacking? *I want to become somebody…………………………! 1. 2. 3. 4.

6. Tilapia broodstock

7. Technician checking fish in small tilapia hatchery facility

22

THANKYOU LONG HARIM BLO YUPELA…………

presented by: JBMari