Keisham Geenita, Sonam Angmo and Bejawada Chanikya Naidu
Northeast India is one of the most biodiverse regions in India, having many rare and endemic fish species. The unparalleled diversity with vast water resources proves this region can be a hotspot for capture and culture-based fisheries.
North-East India, comprising of 8 states, i.e., Assam, Sikkim, Meghalaya, Tripura, Manipur, Arunachal Pradesh, Nagaland, Mizoram, is a region with rich biological diversity. The prosperous bio-diversity of this region can be attributed to its geomorphology and the collision of the Indo-Chinese and Myanmar plates, which helps in the formation of Himalayas & Indo-Burman ranges1.
This region is one of the 12 mega biodiversity rich zones of the world and a part of the Indo-Burma Hotspot, which is one amongst the 34 biodiversity hotspots of the world, is home to various endemic aquatic biota such as Aborichthys, Akysis, Badis, Bangana, Chaca, Conta, Erethistoides, Erethistis, Exostoma, Myerglanis, Olyra, Parachiloglanis, Pareuchiloglanis, Pseudecheneis, Pseudolaguvia etc.Unfortunately, many of these species are threatened now due to the natural and anthropogenic hazards.
Fish diversity, fishery resources and their management
In total, there are 422 species of fish belonging to 133 genera and 38 families from NE India, which represents food fish, ornamental fish, recreational, and sport fish1. Cyprinidae family has the largest diversity among the north-east fishes consisting of 154 species. Hillstream fishes such as Psilorhynchus, Garra, Glyptothorax, Pseudocheineis, Pseudolaguvia, Myerglanis, Exostoma, Erethistes, Parachiloglanis, Pareuchiloglanis, etc. with the most remarkable adaptations are found in this region. The other families found in this region include Anguillidae, Engraulidae, Heteropneustidae, Chacidae, Aplocheilidae, Syngnathidae, Sciaenidae, Osphronemidae, Ophichthidae, Pristigastiridae, and Tetraodontidae. Estuarine fishes such as Tenualosa ilisha, Rhinomugil corsula, Johnius coitor are also can be observed during their migration to the Brahmaputra river system for breeding. Further, the occurrence of the unique pipe fish Microphis deocata of the family Syngnathidae, which usually occurs in the marine environment, is also reported in this region.
Exotic species such as Cyprinus carpio, Ctenopharyngodon idella, Puntius gonionotus, Hypophthalmichthys molitrix, Hypophthalmichthy nobilis, Oreochromis mossambicus, etc. have invaded the natural water bodies, and their culture in ponds commercially has been practiced. The intrusion of C. gariepinus, Piatractus brachypomus (locally called Pacu or Rupchada) in different wetlands, river tributaries, and river systems have emerged as a serious matter of concern. A complete database of species available in this region is lacking due to difficulty in accessing because of topography, terrain features, inaccessibility, and lack of proper language communication. To take up a successful conservation program, correct identification of species, an evaluation of the degree of threats to species available in this region is essential.
NE region is bestowed with vast water resources in the form of torrential hill streams, rivers, lakes, floodplain wetlands, reservoirs, mini-barrages, etc. which can be substantially utilized for fisheries and aquaculture purposes and provide ample scope for fisheries development in this region. The floodplain wetlands (Beels) of Assam support many species of resident and migratory waterfowls, air-breathing, insectivorous, and other economic sized fishes. However, due to the diversion of river courses, siltation, habitat destruction, macrophyte infestation, change in the water regime of the floodplains occurred, which significantly reduced the productivity of such ecosystems3. If scientifically managed, fish production in such ecosystems can be enhanced significantly.
The Loktak lake of Manipur is the largest freshwater lake in NE India and the only floating lake in the world acts as a source of livelihood for people residing in and around the lake. Although the culture of freshwater fishes in cages has been initiated in this region recently, mostly capture-based fisheries practices are carried out. However, lack of proper management measures for the lake, almost no fishing ban season, the proliferation of Phumdis, construction of Ithai barrage, etc. have resulted in declined productivity of the lake4. The reports of the disappearance of indigenous fishes previously present in the lake are a serious matter of concern. For the conservation, development, improvement of the lake environment, the Government of Manipur established the Loktak Development Authority5.
NE India is also home for endemic ornamental fishes, and at least 250 species of fish have vivid ornamental value. The majority of these fishes marketed are wild-caught, and about 85 % of the ornamental fish export from India is from the NE region. The endemic ornamental fishes such as Channa spp., Trichogaster spp., Nandus spp., Lepidocephalus spp., Amblypharyngodon spp.,Acanthopthalmuspangia, Balitorabrucei, B. tileo, Batasiotengana, Erethistespussilus, etc. are of good demand6. Lack of standardized breeding technology for the indigenous ornamental fishes has led to their overexploitation in the wild. Furthermore, various natural and anthropogenic factors like the construction of dams on river systems, which leads to the disruption in water flow and water exchange along with climate change factors, have caused a threat to the endemic fish population. The current status of the fish species is needed to be surveyed and evaluated for their conservation and for developing conservation strategies.
Owing to the immense, untapped, pristine aquatic resources in the form of rivers, streams, and lakes, Northeast India offers a tremendous opportunity for recreational/ sports fishery and eco-tourism. The NE being home to various game fishes like mahseer, trout, snow trout, carps, catfishes, featherbacks, and other fishes, attracts anglers from all over the country, and they are highly interested in this region.
They employ various methods to catch fish such as fly fishing, spoon fishing, bait casting for mahseers; noose and line method for capturing snow trout; traps (Seppa), lift nets (Porongijal), pole and line (Boroxi), drift lines (Nolboroxi) and plunge baskets (Polo, Juluki), etc. in the Brahmaputra drainage and floodplain wetlands. Angling Competitions and expeditions are conducted regularly, based on the principles and guidelines of catch and release of the state of Arunachal Pradesh7. Stocking of seeds, establishing trout hatcheries, construction of trout raceways to expand trout fisheries has also been done in various states of NE India in recent years. Various angling associations (The Assam Bhoreli Angling and Conservation Association; Anglers Association Nagaland, etc.) are being formed to popularize sport fishing and to create awareness to conserve and preserve endemic and indigenous fishes.
More than 90% of the population in North East India are fish eaters, while most of the time, the demand exceeds the supply. The total fish production from NE states was 4.11 lakh tons during 2015-2016, of which Assam contributes the major share, followed by Tripura and other states8. On an average, 0.214 million tons of fish are produced annually from this region, of which 50% comes from aquaculture. According to an estimate, 6 kg of fish is available per person per year, while the quantity to meet the nutritional requirement is assumed to be 11 kg per person9. Among the NE states, the highest per capita fish consumption was reported in Tripura.
NE region contributes only 5.9% to the Indian fishery sector (DAHDF,2014). Indian major carps and Chinese carps are major species cultured, mainly in composite fish culture practice, while other species being cultivated include Pengba (Osteobramabelangiri– state fish of Manipur), Ompoksps, minor and medium carps, and other fish. Fish seeds are produced mainly using the traditional “hapa” breeding technique. For large scale production of seed, Chinese circular ecohatchery is used, and at times IMC seeds used in culture are procured from West Bengal. Integrated fish farming such as paddy-cum-fish culture, pig-cum-fish culture,poultry-cum- fish culture, etc.is being practiced in the state of Manipur, Tripura, Nagaland, and Arunachal Pradesh. Culture potential and breeding technique of indigenous fish species such as Puntius gonionatus, L.gonius, P.sarana, O. belangiri by using inducing agents and hormones have been realized.
Challenges, constraints, and future directions
Since the majority of the people in NE states consume fish and to meet their demand, fishes are imported from other parts like West Bengal, Andhra Pradesh, Bangladesh, Myanmar, etc. Though the NE region has the utmost potential for development, it is not properly understood and realized. Expansion of aquaculture vertically as well as horizontally, diversification of fish species being cultured, pen and cage culture practices in the floodplain wetlands, utilizing low-lying waterlogged areas for the culture of air-breathing fishes, and adopting periphyton- based aquaculture system may help in boosting the fish production and meeting the demand for food fishes.
The illegal introduction of exotic fishes by fish farmers have caused several ecological impacts and is threatening the local fish population. Exotic species such as Pangasiussutchi, O.niloticus, hybrid catfishes like Clarius gariepinus, and C.macrocephalus have already invaded the natural ecosystem and are now becoming very popular among farmers.
Besides, one of the major constraints in enhancing fish production in the NE region is the lack of good quality seed. Other constraints include lack of proper transportation facilities, infrastructure facilities, inadequate transfer of technologies, lack of active extension personnel, etc.
(The authors are Post Graduated from Indian Council of Agricultural
Research (ICAR) – Central Institute of Fisheries Education, Mumbai. Views
expressed are personal.)