Aquaculture

Aqua” means water and “culture” means practice. Aquaculture means culture of any commercially important aquatic organisms by deliberate manipulation of their growth,

According to FAO,

Aquaculture can be defined as the farming of aquatic organism including fish, mollusks, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process such as regular stocking, feeding, fertilization, harvesting etc.

Cost:

Also called shore, broad area of land that borders the sea.
 
Functional definition:
It generally means the land behind the seas.

Coastal aquaculture:

Coastal aquaculture means all types of aquaculture practice in the coastal region and coastal environment.

Types of coastal aquaculture:

         a) Raft culture
         b) Cage culture
         c) Pen culture
         d) Crop rotation culture
         e) On bottom culture

Objectives of coastal aquaculture:

1)       To get proper knowledge about the whole system of coastal aquaculture.

2)      To know the present condition of this culture system.

3)      To detect the problems that exists in the coastal aquaculture system.

4)      To know the prospects of coastal aquaculture.

5)      To adopt benefiting technique of hatchery and nursery management.

6)      To improve socio-economic condition.

7)      To improve socio-economic condition.

8)      To remove unemployment problems.

9)      To meet the demand of protein.

10)  To earn foreign exchange.

11)  To produce numerous fry in the hatchery to protect the extinction from the species.

12)  To get desirable species all the year round.

13)  To maintain biodiversity in coastal water body.

14)  To be self depended.

Site selection for a coastal farm (for Penaeus monodon)

The selection of a suitable site always plays a major role in shrimp farming. The suitability of a shrimp farm depends on several factors. These are as follows:

1. Accessibility: Accessibility is an important consideration in site selection. Coastal aqua farm should be accessible by land or by water for convenient marketing of shrimp product and for transporting supplies, materials, and other necessities. It is important that the farm be within 3-6 hours traveling time from the hatchery to avoid excessively long transportation time of the larvae and should be within 10 hours from the processing plant to avoid deterioration of the product.

2. Meteorological and hydrological information: All available meteorological and hydrological information about the area (generally available from meteorological and irrigation authorities), such as range and mean monthly air temperature, rainfall, evaporation, sunshine, speed and direction of winds, floods, water table etc, should be gathered.

3. Elevation: The land should be free from deep flooding and site also should be plain land. The best areas for shrimp farming are those with average natural ground elevations of about 1-3 meters above mean sea level or at least 1 meter above the highest high tide level to allow drainage and harvesting.

Low land or mangrove swamps are not ideal sites because of the following reasons:

1)      The low land may be made up of potential acid sulfate soils.

2)      Deeper ponds cannot be built and complete drainage is impossible.

3)       Construction costs in swamp land are always higher.

4. Climate: The coastal aqua farm should be located in areas with no pronounced dry and wet seasons, a short dry season, or with evenly distributed rainfall to avoid the risk of stunting or mass mortality of shrimp due to excessively high or low salinity.

5. Vegetation: The nature of the vegetation indicates the soil type and elevation of the water table. Lands under grass or low shrubs are better suited, as dense vegetation (tall trees) makes clearing more difficult and expensive.

6. The existing and future sources of pollution: Information on development plans is gathered for the neighborhood areas just to ascertain that there will be no adverse effects of pollutants (air, water or soil) on the fish to be cultured and other biota.

7. Soil characteristics: Following Conditions of soil are suitable for fish culture:

a)      Sandy clay to clayey-loam soils.

b)      Clay or loam-based soil containing more than 90% clay is preferable.

c)      pH between 6.5 to 8.5 preferable.

d)     Total nitrogen 0.1%; total phosphorus 0.1%; organic carbon> 1.0%; free CaCO3 5%.

8. Source of watch and its quality:

A dependable source of water supply must be available within or near the site.

Favorable physico-chemical properties of the water for fish culture are as follows:

a)      Water should be free from agricultural and industrial pollution.

b)      The pH of the water preferably ranges from 7.5 to 8.5.

c)      The dissolved oxygen level is preferably not lower than 4 ppm.

d)     The water is preferably to be rich in microorganisms.

e)      The water must not be too turbid.

f)       The salinity of the water for shrimp farm should be from 25 to 30 ppt.

9. Tidal fluctuations: The characteristics of the proposed site should be known.
Areas best suited for shrimp farming should have moderate tidal fluctuations preferably 2-3 meters. In areas where the tidal range is greater than 4 meters, the site may prove uneconomical to develop or operate as large and high pond dikes will be required. In areas where tidal range is less than one meter, water management will be expensive requiring the use of pumps.

10. Social issue: The need for the participation of the local community in aquaculture activities.

11. Seed supply: Proximity to sources of wild fry and/or hatcheries reduces transport costs of the farmer as well as transport stress of the fry.

12. Feed availability: Obtaining feed from the nearest source and transporting these feed to the farm site within the shortest possible time.

13. Marketing opportunity: The site is easily accessible by markets, fish ports. Processing plants, and ice plants, and linked by communication facilities to major centers.

14. Availability of manpower: Availability of manpower for construction and operation is needed.