Site Selection for Aquaculture

I N T R O D U C T I O N Success or failure of any aquaculture venture largely depends on the right selection of the site. In choosing a site several factors other than the physical aspect of the site are to be considered. The factors to be considered cut through various disciplines and range from socio-economic aspects of aquaculture to all the physico- chemical and biological conditions of the environment.

Sites suited for aquaculture and culture types Several types of water bodies can be used for fish culture - the choice of a specific body depends on the objective of the investors and also the type of aquaculture. Among the sites suitable for aquaculture could be listed: land-swamps, rivers, stream beds; coastal areas - bays, estuaries backwaters, lagoons, salt marshes and mangrove swamps; lakes, reservoirs and other water bodies, including irrigation tanks and canals.

Contd.. The specific site to be chosen would be based on the requirement of the culture systems. Static water ponds are the most common. Most of these are confined to freshwater areas, but brackish water ponds are also becoming more common. Variety of culture systems which can be developed in open waters - the stocking and management of open waters themselves being major occupation, e.g. extensive stocking of man-made reservoirs and lakes.

Contd.. In the larger freshwater bodies and coastal areas cage and pen culture can be developed. Site selection for these culture systems has to be carefully done, based on the requirements of the species to be cultured and the structures to be erected.

Culture types (Systems) The different culture systems in vogue are listed below: Static water ponds, running water culture, culture in recirculation systems. Culture in rice fields and integrated culture systems, as the duck-cum-fish and pig-cum-fish culture - or any fish-livestock-crop combination; Culture in raceways, cages, pens and enclosures; also mollusc/oyster culture - hanging, on-bottom and stick methods

FACTORS AFFECTING SITE SELECTION IN AQUACULTURE There are several aspects to be considered for the selection of site for a culture system. Both technical and non-technical aspects will have to be considered, which are: Socio-economic, political and legal factors Climatic factors and Major environmental factors. Under the last category various aspects, such as, topography and ground elevation; soil; water supply, and dynamics, physical, chemical and biological features of water, land-vegetation etc will have to be considered.

Contd… The selection of a site and success of a project is much dependent on considerations which are non-technical - such as acceptability of the fish produced (consumer preference), marketing facilities, labour available etc, or certain political or legal considerations.

Main environmental factors Topography and ground elevations Soil Water supply, quantity and dynamics Physical and chemical features of Water Productivity Fouling/availability of spat (for mollusc culture) Type and density of vegetation

Socio-economic considerations Socio-economic aspects such as social and religious customs'; consumer preference ; nature of manpower (labour) - quality and quantity - available; transportation and communication facilities; i.e. infrastructure facilities; accessibility and nearness to market; and also costs and availability of construction materials.

Political and legal considerations The project can fit into the country's or provincial plan for development of industry and agriculture. Legal aspects, such as security of tenure, maritime laws controlling coastal waters, legal size limits with reference to the ponds/culture area, species under culture, and closed reasons, should also to be considered. Several countries already have certain regulations concerning these legal aspects, some of which are in force, much before aquaculture was thought of as an industry.

The importance of a good site The whole success of your enterprise depends on the selection of a good site for your fish farm. The layout and the management of your farm will largely be influenced by the kind of site you select. The site strongly affect the cost of construction, the ease with which the ponds can be managed, the amount of fish produced and, in general, the economics of your enterprise.

Preliminary decisions Before starting to look for a site, you should have a clear idea of the type of fish farm you wish to build. Some of the questions you should ask yourself are the following. (a) Which level of production do I plan to reach, subsistence or commercial? Which scale, if commercial? (b) Which culture system shall I adopt? extensive or intensive; one or several species; seasonal or year-round.

Contd… (c) Shall I use fertilizers or fish feeds or both? (d) Which species of fish shall I produce and at which size shall I sell them? (e) Shall I have to buy juveniles or produce them all myself? (f) Shall I try to integrate my fish farming activities with other agricultural productions I already have? Shall I also start raising animals on my farm? (g) Which area of the farm do I wish to develop immediately? Will I develop other areas later, as a second phase? 2. If you cannot answer these questions by yourself, you should look for assistance, for example from the local extension agent specialized in fish farming. You can also check with other farmers to find out what choices they made and why.

Major considerations The major factors to be considered when selecting a site for the construction of a freshwater fish farm are water supply, soil quality and local topography. It is essential that you have the required supply of good quality water at the time needed to operate your fish farm. Preferably, it should be available all year round. you should know about soil to be used for fish farming. Remember to: avoid sites with rock outcrops, gravel beds, sandstone and limestone; beware of sandy soils and termite mounds; give preference to soils such as sandy clay, silty clay loam and clayey loam.

How to begin planning your fish farm construction Now that you have selected the site of your fish farm, you should initiate the planning of the fish farm, which has two main related components: the organizational planning, in which you decide where, how and in which order you will build the farm. the physical planning, in which you decide on layouts, detailed design and earthwork.