AQUACULTURE - INTRODUCTION
Aquaculture, also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other aquatic organisms. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the harvesting of wild fish. Mariculture refers to aquaculture practiced in marine environments and in underwater habitats.
SUMMARY [AQUACULTURE IN PAKISTAN]
Aquaculture is a rather recent activity in Pakistan and is still in its infancy; nevertheless there is immense potential for development of the sector. Despite its vast fresh, brackish and marine water resources only carp culture is practiced in inland waters and only on a limited scale, carp are cultured in earthen ponds, using mostly extensive farming practices with very little inputs. In Pakistan, the fish fauna is rich but only seven warm water species and two cold water species are cultivated on a commercial scale. Trials experimenting with shrimp culture have been carried out in the Indus delta region but it did not succeed due to the non-availability of hatchery-produced seed.
The fisheries sector as a whole contributes to about 1 percent to the country's GDP and provides jobs for about 1percent of the country's labour force. Freshwater carp farming is the major aquaculture activity in three of the country's four provinces (Punjab, Sindh and North West Frontier Province [NWFP]). The northern mountains of Pakistan have good potential for trout culture but production in these colder regions is still very small.
Aquaculture in Pakistan is basically a provincial responsibility; at the central level fisheries is the responsibility of the office of the Fisheries Development Commissioner (FDC) working under the Ministry of Food, Agriculture and Livestock (MINFAL). The office of the FDC is responsible for policy, planning and coordination with provincial fisheries departments and other national and international agencies. The Pakistan Agricultural Research Council (PARC) is the country's largest research organisation and is responsible to MINFAL. Some universities in the country are also involved in basic fisheries research.
About 13000 fish farms have so far been established across Pakistan, the size of these farms varies considerably, however, the average farm size ranges form 5-10 ha. No direct data on the number of fish farmers employed in this sector is available as fish farming in most parts of the country is carried out as an integral part of crop farming. According to a best estimates, about 50000 people are either directly or indirectly employed in the sector.
FARMING SYSTEMS DISTRIBUTION AND CHARACTERISTICS
Pakistan has substantial areas of inland waters as a result of its location as the drainage basin for the Himalayas. The region between 33 o N and 20 o N consists of a network of rivers, canals, reservoirs, lakes, waterlogged areas and village ponds, etc. with a total area of about 8.6 million ha. Of this total, some 30000 ha correspond to the area utilized for cold-water trout production and other commercially important sport fishes such as mahseer (Tor tor) and snow trout (Schizothorax richardsonii).
About 110000 ha comprise the warm water natural lakes found in Pakistan of which the majority (101000 ha) are found in Sindh Province, which has a mix of both freshwater and saline lakes. In some of these saline lakes, the salinity levels are higher than sea water thereby limiting their potential for fisheries production.
While these resources possess great development potential to help meet the increasing demand for protein from the population, fish farming has never been a major economic activity neither have freshwater fish ever been a major food source for the inland population. The per capita consumption of fish products is currently around 1.9 kg which is amongst the lowest in the world.
The provinces with the greatest potential for development are Punjab, Sindh and to a lesser extent NWFP, the total number of farms in all provinces being approximately 13000. Although the fish farming through culture in ponds and other natural water bodies has been practiced for several decades, it is only during the last two decades that any impetus for further development can be seen with about 60470 ha of freshwater ponds being used for fish culture.
In Sindh Province, the majority of the farms are located in Thatta, Badin and Dadu, the three districts through which the River Indus passes. Badin and Thatta have water logged floodplain areas which are suitable for fish farming. In Punjab Province, farms are located mostly in irrigated areas or where there is abundant rain and the soil is alluvial. As a result, Sheikhpura, Gujranwala, and Attock districts have larger number of farms and constitute around three quarters of the total number of farms in Punjab.
The NWFP has comparatively fewer farms, because of the cold climate in the mountainous areas. Trout farms are located in Chitral, Swat, Dir, Malakand, Mansehra, Federally Administered Tribal Area (FATA) and other parts of NA. Carp culture is practiced in Dera Ismail Khan, Kohat, Mardan, Swabi and the Abbotabad districts of NWFP.
Inland fish farming is under the control of the provincial governments, who supply seed, operate hatcheries, provide extension services, collect primary data and promote fisheries through extension manuals, brochures and by arranging seminars, etc. Existing farming methods have not developed. However, as a result of a steady stream of newcomers to the sector, there is a slow but steady improvement in technology over time.
In the past, most fish farmers stocked their ponds only with indigenous species such as catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala) and common carp (Cyprinus carpio). More recently, two fast growing species, the grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix), have been introduced for culture under modern polyculture systems to increase the fish yield per unit area. These two species have good economic values; have gained a reputation and became popular amongst the producers as well as consumers. Two species of trout namely brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) are cultured in NWFP, AJK and NA.
ANIMALS OF AQUACULTURAL IMPORTANCE
The following organisms are suitable for culture in an aquatic body in addition to fishes.
1. Rana catesbiana 2. R. hexadactyla 3. R. tigrina
2. SHRIMPS AND PRAWNS:
1. Penaeus mondon 2. P. indicus 3. P. carinatus 4. P. setiferus 5. Palaemon styliferus 6. Metapenaeus monoceros 7. M. brevicornis 8. M. ensis
1. Homarus americanus 2. H. vulgaris
1. Scyila serrata 2. Portunus trituberculatus 3. cancer products
1. Crassostrea madrasensis 2. C. angulata 3. C. commercialis 4. C. gigas 5. Ostrea edulis
1. Mytlius edulis 2. M. galloprovincialis
1. Sepia sabaculeata 2. Sepioteuthis sepioidea