Campaign to wipe out African catfish from Periyar lake
The African catfish that thrived in the waters of the state, at the expense of many native fish species that they gobbled up, is finally meeting its nemesis – the Conservation Research Group (CRG) of the St Alberts College in Kochi.
The CRG, as part of its drive against exotic fish species invading our water bodies, is launching a campaign against African catfish in the Periyar Lake. On April 29 and 30, they will lead a mass programme to catch the African catfish from the Lake, as an initial step towards an ‘Exotic fish-free Periyar Tiger Reserve.’
“The waters of the Periyar Tiger Reserve have evolutionary distinct and globally endangered freshwater fish. As it is, they are threatened by many factors and even in these last few habitats they are predated upon by these relatively alien species. As part of protection and conservation measures, we are going in for mass removal of the catfish from the Periyar Lake,’’ said K Kishnakumar, who is the programme co-ordinator of the CRG, Kochi.
Although aquaculture of this alien fish species is banned in the country, ease of rearing the fish, the low operational costs and high profits have led to intensive culture. The African catfishes are known to escape from the ponds that they are reared to larger water bodies and predate on the native fish species.
’Another important aspect of the predatory catfish is its ability to switch from one prey to another, indicating a grave threat to a number of native fish and not just any one fish. Introduction and subsequent colonisation of these catfishes in new environments have led to decline and extermination of local species,’’ said Krishnakumar.
Depletion of as many as 56 species of native fish in Bangladesh has been linked to the introduction of the African catfish.
The scientists warn that the same thing could happen here too. There are several fish species that have extremely restricted distribution inside the Periyar Tiger Reserve. Some of them include Garra periyarensis, Garra mlaparensis, Nemacheilus menoni, Nemacheilus periyarensis, Homaloptera silasi, Hyselobarbus eriyarensis, Crosscheilus periyarensis and Lepidoygopsis typus.
These local fish species are under threat, not only because the alien catfish species predate on them but also because they compete for food.
The CRG from St Alberts College believes that there was no other way but eradication of the African catfish, to protect the native species.
Along with the eradication, they intend to carry out awareness campaigns to stop such introductions in future and possible escapes.
The team will start with Anavachal canal, which is reported to have the highest density of exotic fish. First, the canal will be cleaned by removing the water hyacinth and plastic. Then with the help of the EDC members and volunteers, African catfish will be selectively caught using drag nets and scoop nets. They will subsequently be taken out of the reserve and sold through the EDC stalls of the Forest Department.
Source : The New Indian Express