INLAND FISH PRODUCTION

The fish production system of inland open water have been classified as (i) Capture fisheries of rivers and estuaries, (ii) Culture fisheries of ponds, (iii) Culture-based fisheries of small reservoirs and floodplain wetlands and (iv) Enhancement fisheries of medium and large reservoirs. In Kerala however, the more significant ones being reservoir, estuarine, brackishwater and freshwater aquaculture.

The production of inland fish in the country during 2006-07 was at 3.9 million tonnes and placing the country as second largest producer of inland fish. The projected domestic requirement of fish in the country by 2020 is estimated at 12 million tonnes, more than three-forth of which has to come from inland sector. Inland sector of Kerala produced over 0.79 lakh tonnes of fish, which accounts for 12.3% of the total fish production of the state. However, at all India level, more than 50% of the total fish production is contributed by the inland sector.

Species-wise inland fish production of Kerala during the past three years is shown in table below. The results indicate that the percentage contribution of six commercially important fish groups listed below remained stagnant.

Species-wise Inland fish production in Kerala from 2003-04 to 2006-07

Reservoir fisheries

Reservoir constitutes the single largest inland fishery resource, both in terms of resource size and productive potential. Fish production from different categories of reservoir like small, medium and large has been estimated at about 50 kg/ha/yr, 12.3 kg/ha/yr and 11.5 kg/ha/ys, respectively, the average being about 20 kg/ha/yr.

In Kerala there are 30 reservoirs with a water spread of 43,000 ha suitable for fish culture. Fish culture is being carried out only in 10 reservoirs. The total catch reported in 8 reservoirs is 77.24 tonnes and the average productivity is 14.07 kg/ha. The important species accounting for major part of the catch are Catla, Rohu, Mrigal, Calbasu, Wallago, Puntius spp., Labeo spp., Mystus spp. etc.

Estuarine fisheries

The fisheries in estuaries of India are above the subsistence level and contribute significantly to the production. One of the peculiarities of the Kerala coastal zone is the presence of a number of backwater and estuaries.Vembanad lake is the largest estuary in Kerala. The estimated area of Kerala’s backwater is about 50000 ha, which produces 14,000-17,000 tonnes of fishes, 88000 tonnes of live clams and 170,000 tonnes of dead shells. Major fisheries group include prawns, mullets, seabass, pearlspot, milkfish etc.

Freshwater aquaculture

The freshwater aquaculture account for over 70% of the total inland fish production. This sector alone contributes to about one-third of the total fish production in the country. India has witnessed considerable advancement to achieve high rates of productivity in finfish and shellfish farming systems with productions up to 15 tonnes/ha/yr of carps, 54 tonnes/ha/5 months of catfishes and 6 tonnes/ha/year of rainbow trout. The average aquaculture production is around 2.2 million tonnes in India. Carps, catfishes, prawns etc form important components of culture practices in terms of cultivable species.

The three Indian major carps contribute to about 84% of India’s freshwater aquaculture production. Other candidate species being air-breathing (Clarius batrachus, Heteropneustes fossilis) and non-air breathing catfishes (Wallago attu, Mystus sp. and Pangassius sp.). Among crustaceans giant freshwater prawn Macrobrachium rosenbergii and M. malcolmsonii and freshwater bivalve, Lamellidens spp. have also received much attention among farmers.

Fish production range under different culture systems is given in table below.

Brackishwater aquaculture

Along the Indian coastline the potential area of 1909 million ha is amenable for brackishwater aquaculture out of which 0.152 million ha was brought under shrimp culture by 2002-03 (table below).

State-wise details of shrimp farming in India during 2002-03

About 52% of the farms are less than 2 ha holdings and are operated by small cultivators. Farms over 5 ha amount to only 19% of the total area under cultivation. In Kerala brackishwater area occupy about 2.43 lakh ha, which has a good potential for shrimp culture. Since the development of this sector, about 3 lakh persons have gained direct employment in aquafarming and about 6-7 lakh persons are employed in the ancillary units and activities.

In brackishwater aquaculture sector, main emphasis has been given to a single species Penaeus monodon by virtue of its excellent export value. Other species such as P. indicus, P. merguensis, P. semisulcatus and finfish species like seabass (Lates calcarifer), grouper (Epinephelus malabaricus), grey mullet (Mugil cephalus), pearl spot (Etroplus suratensis), milkfish (Chanos chanos), and mud crabs (Scylla serrata, S. tranquebarica) are also ideal for brackishwater  aquaculture. Along with this the popularity of mariculture of green (Perna viridis) and brown mussel (P. indica), edible oyster (Crassostrea madrassensis, Saccostrea cucculata) and clams (Villorita cyprinoides) is also growing in Kerala.

Last updated: 29-3-2008