Fishes of Karnataka
Fresh water fishes of Karnataka
The geographical area of Karnataka is 192,204 sq. km which is about 5.85% of the total area of the Indian Union. The state lies between the latitudes 11° 12´ N and 18° 12´ N and longitudes 73° 48´ E and 78° 18´ E. The State has 4.57 lakh ha. of inland waters in the form of reservoirs (2.22 lakh ha.) ponds and tanks (2.35 lakh ha.) river stretches running to a total length of 5,813 km, 3,000 km of irrigation canals and a coast line of 320 km. It has a moderate climate and receives an annual average rainfall of 120 cm. It is said that the climate and rainfall of a region largely determines the land size pattern and the faunistic elements available in the aquatic ecosystem.
With the Western ghats (Sahyadri) forming a major water divide, there are short and swift flowing rivers in the west draining into the Arabian sea. Notable among them are Sharavati, Kali, Netravati, Bedthi/Gangavalli, Aghanashini, Varahi and Chakra. To the east of the major divide, flow the rivers rishna, and Cauvery. A major part of the upstream of river Krishna and its tributaries Tungabhadra, Ghataprabha, Malaprabha, Bhima and Vedavati flow through northern Karnataka, pass through Andhra Pradesh before joining the Bay of Bengal. The Cauvery river in the south flows down the eastern slopes of the ghats, passes through Tamil Nadu before joining the Bay of Bengal. The main tributaries Hemavati, Kabini, Arkavati, Shimsha, Palar, Uttara and Dakshina Pinakini, Manjira and Karanja are the only tributaries of river Godavari found within the state boundary.
Annual fish production in the state from the freshwater sector is about 1.2 lakh metric tonnes as against an estimated potential of 2.6 lakh metric tonnes. In order to boost the inland fish production to meet the ever growing demand, the State Department of Fisheries has laid more emphasis on the culture of fast-growing Indian major carps like Catla catla, Labeo rohita and Cirrhinus mrigala, as also exotic fish - Cyprinus carpio, Hypophthalmichthys molitrix and Ctenopharyngodon idella. These introduced fish species have adopted well in the various types of freshwater biotopes. Since few years, the introduced Cyprinus carpio (Common carp) and inadvertently entered Oreochromis mossambica (Tilapia) have dominated the inland water fishery, as they breed and multiply fast in a short span of time. The introduction of all these fish species, in a way, has resulted in the decline in the population of of indigenous fish species comprising of Labeo, Cirrhinus, Puntius, Catfish, Murrels, etc. The culture of African catfish - Clarias gariepinus undertaken by private entrepreneurs is going to damage the entire picture of indigenous fish fauna in particular if corrective measures are not implemented at the earliest.
The decline in indigenous fish population and fish production from freshwaters can also be attributed to the damage caused to their habitat through the construction of dams and anicuts, indiscriminate fishing, siltation, weed infestation, pollution by industrial and domestic effluents, etc. Therefore, urgent measures to restore the bio-diversity of indigenous fish and their habitats are required to be undertaken.
Until now in Karnataka, 201 freshwater fish species belonging to 9 Orders, 27 Families and 84 Genera have been recorded, of which 40 fish species are under 'threat' and urgent conservation measures need to implemented to ensure their survival. The systematics of freshwater fish species recorded from the inland waters of the State is based on the work carried out by Jayaram (1999).
Marine water fishes of Karnataka
Data on marine fishes is essential for identifying fish resources which in turn are of great help in formulating developmental plans or enhancing fish production as also adopt conservation measure. Implementation and monitoring of protective measures ensure rich biodiversity.
Karnataka state is endowed with vast marine and fresh water resources. The state has 300 km of coast line, 27,000 sq. km continental shelf and 87,000 sq. km of exclusive economic zone besides 8,000 ha of brackish water area. The marine fish production potential is estimated at around 4.25 lakh M.T. per annum. Prior to introduction of mechanical fishing crafts and gear, marine fish landings were around 0.18 lakh M.T. per annum. With the introduction of mechanized trawlers for harvesting bottom dwelling fishes, and purse seines for pelagic fishes and gill netters for mid water species, the fish landing recorded a high of 2.23 lakh M.T. (1996-97) in a span of about 22 years (1964-1996). In subsequent years, there was gradual decline in fish catches and a low of 1.28 lakh M.T. was recorded in 2001-2002.
During the 1997-2002 there has been decline in fish catches have been observed and the average fish production was around 1.70 lakh M.T. per annum, though a fleet of 7,000 mechanised and 19,000 non-mechanised fishing vessels are engaged in operating different types of fishing gear. The landings of some fish species have shown significantly declining trend and keeping these facts in mind, certain conservation measures are being enforced. Declaration of a 'closed season' for fishing during monsoon (June to August) under Karnataka Marine Regulation Act is a welcome measure. Similarly banning the operation of mechanised fishing vessels in a 10 KM radius of foreshore has set apart a 3,000 sq. km area for traditional fishing and thus prevent over exploitation in foreshore water. The ban on exploiting brood fishes during spawning season (Monsoon) and prevent catching of juveniles using small meshed fishing nets are measures aimed to improve fish production in years to come.
Decrease in fish production is attributed to discharge of domestic and untreated industrial effluents, detergents, oil spillage, indiscriminate fishing by foreign fishing vessels in E Z area etc. The marine environment should be protected by strict enforcement of the Marine Fishing Regulation Rules and other marine laws.
In Karnataka, mackerals, sardines, anchovics and other elupeids form the dominent pelagic fishing while catfishes, Sciaenids, Perches, sharks and rays etc. constitute the deep sea fishing. Soles, and prawns form the major demersal fishery.
For literature on marine fishes the published works of Day (1878-1889), Munro (1955), Misra (1962), Smith (1967), FAO (1974), Rajagopal et. al. (1978), Jones and Kumaran (1980), Talwar and Jhingran (1991), MPEDA (1998) and CMFRI (2000) have been referred. For classification of fishes, Berg (1940) has been followed.
There are 276 fishes inhabiting marine and estuarine waters along the West coast of Karnataka are described.
Last updated on: 01-01-2011 | Designed and developed by EMPRI