IMPHAL, July 6 - Environmental changes, pollution, developmental activities and introduction of non-local fish species for pisciculture have led to depletion of indigenous fish in Manipur.
The hydrological system of the State has changed due to human pressure while the quality of wetlands has also degraded due to lack of awareness, former Vice Chancellor of Manipur University Prof H Tombi said.
The State had more than 300 wetlands across the valley and hills some time in 1947, but except a few including Loktak, most of them have vanished now.
As a result, many native fishes including the migratory ones from the Chindwin river (Myanmar) have disappeared from Loktak and other wetlands, Prof Tombi added.
Some experts, when contacted, said that farming of high-yielding fish varieties and drying up of wetlands are responsible for the decline in the numbers of native and indigenous fish varieties.
Many indigenous fish species have been endangered, according to Prof W Vishwanath of the Life Sciences department of the Manipur University, who has discovered around 80 new fish species in Manipur, home to 210 fish species under 33 families including around 100 indigenous species.
The International Union for Conservation of Nature has also listed seven local fishes of Manipur as �endangered freshwater fish species�. These include ngakha meingangbi (Puntius manipurensis), ngatup 1 (Schistura kanjupkhulensis), ngatup 2 (Schistura minutes), ngatup 3 (Schistura reticula), ching-ngakra (Pterocryptis barakensis), ching-ukabi (Badis tuivaiei) and nung-nga (Psilorhynchus microphthalamus).
Besides, nganap, ngahei, sareng khoibi, ngasep, etc., are also under strain.
The State fish, pengba, which was found in abundance in the Loktak lake and Nambul river, has become extinct in its wild habitat and is only bred in farms now.
Besides their food value, local fish species play a vital role in preserving the rich culture and traditions of the State. Traditionally, ngahei was given to young babies on �chak-umba�, the first solid food feeding day for babies in the Manipuri society, while the tiny nganap forms part of the meals of newly-wed Manipuris.
�Earlier, we used to get these fishes in lakes, but it is very hard to find them now,� said Ibemu, a fish vendor in the busy women�s market here. Nowadays some vendors sell dried nganap for social and religious occasions, she added.
Upstream areas of major rivers of the State are the breeding ground of indigenous fish species, including those flowing from Myanmar. But dumping of waste and sewage into rivers and rampant use of fertilisers and pesticides in agriculture, have led to the disappearance of many local species from the markets in the past two decades.
Stating that indiscriminate fishing of fingerlings and excessive use of chemicals in agriculture are the key reasons for the disappearance of the local fish varieties, Lokeshwar of the USTM added,
Prof Tombi, recommended opening Moramba Marin, a stream connecting Chindwin river (Myanmar) and Pumlen, an associated wetland of Loktak, to help revival of the native fish species in the State instead of making a fish ladder at the Ithai barrage, a 35-foot dam built across the Manipur river to generate 105 MW of power.
Fishmongers have taken to selling fingerlings of indigenous local species in the markets without any restrictions from the authorities concerned. The State Fisheries department is also slowly waking up to the dangers posed by mass production of non-local rohu, grass carp and common carp to meet the State�s annual shortfall of 10,000 metric tonnes, and is now encouraging farming of native and endangered fish varieties.
�We have taken up breeding and culture of five local fish varieties including nganap, ngaton, ngakrijou, ngakra and pengba, while some of the farmers have already started commercial production of pengba and ngaton annually,� Director (in-charge) of the State Fisheries department H Biramani said. But most fish farmers are not ready to take up nganap and ngakrijou farming considering their present market value.
