Experimental fishing in Hirakud Reservoir, Orissa (1965-67)

The comparative efficiencies of simple gill net, vertical line net and framed net in exploiting the fishery of Hirakud Reservoir in Orissa were studied. Though comparatively costlier to fabricate, the framed net gave better results than the other two.

The morphometrics and the proximate composition of the edible fresh water mussel Lamellidens lamellatus (Lea) from Bathalagoda tank, a man made reservoir in Sri Lanka

Morphometric characteristics of Lamellidens lamellatus were studied using a random sample of 138 individuals collected from Bathalagoda reservoir in Kurunegala district. The largest number of individuals in the collection was between 40-50 mm in length. They had a body weight between 60-80 gm. The most abundant bio-chemical component in the adductor and in the foot was protein. Carbohydrate and lipid quantities were almost equal while ash showed the least value. The total protein content ranged from 48.8% to 73.4%; the carbohydrate content from 12.64% to 23.8%; and lipid content from 12.0% to 28.1% of their dry weight. It was found that there were significant relationships between the length and the body weight; and between length and volume.

Reservoir fishery resources of south-east Asia

Although the reservoir area in south-east Asia is considerable, the fish production is low in the majority of reservoirs. Although high fish production has been recorded in a number of reservoirs in Sri Lanka and Indonesia, high fish production in reservoirs has with few exceptions resulted from the introduction of typical lake species from Africa. Addition of further lake fish species especially into deeper reservoirs will probably increase present fish yields. Diversification of the lake fish fauna can be achieved by introduction of species indigenous to the region like Etroplus suratensis. In this introduction of fish species, three points may be noted with specific reference to Tilapia spp.: (a) Lakes without indigenous cyprinids show marked fluctuation in fish catch with the introduction of Tilapia, and this could be stabilised by the introduction of predators and more diverse species. (b) Lakes with a moderate diversity of fish fauna show a high stabilised production with the introduction of Tilapia, presumably because of the effect of predator pressure on excessive Tilapia breeding. (c) Lowland lakes with a rich diversity of indigenous fish species colonising lakes may not require the introduction of Tilapia. Introduction of invertebrates into reservoirs in south east-Asia has not been done deliberately so far. However, the experience in other parts of the world, notably the Soviet Union, indicates that such introductions are likely to prove beneficial and to increase fish production. The potential for a considerable increase in fish production from reservoirs exists in south-east Asia. Proper management is likely to cost less than what is required for fish culture. Rural areas are likely to benefit most from increased fish production in reservoirs, and this might be a way to provide cheap protein where it is most urgently needed.

Post impoundment changes in the fish fauna of Kaptai reservoir, Bangladesh

Based on the present investigation and reviewing the published and unpublished documents critically, this communication considers the post impoundment changes in the fish fauna of Kaptai reservoir. Investigation reveals that a total of 73 species of fish belongs to 47 genera, 25 families and 2 species of prawn are present in the reservoir. Of them, 31 are commercially important, 6 and 9 species are newly identified.

Rational exploitation of Catla catla (Ham) from Hirakud reservoir: a preliminary account

Frame nets and simple gill nets of identical mesh size were experimented to determine their comparative efficiency for exploiting economic size group of Catla catla. The results indicated that frame nets of 90 mm mesh bar as the most effective.

Eradication of uneconomical fishes with simple gill nets at Hirakud reservoir

Experiments with simple gill nets of mesh bar 25, 30, 35, 40 and 45 mm were carried out to determine the suitable mesh size for the eradication of the uneconomical fishes of Hirakud reservoir. Results show that net with 25 mm bar is more suitable particularly for Gudusia chapra (Ham), Rohtee cotio (Day) and Eutropichthys vacha (Ham).

Column set gill net fishing in Gobindsagar reservoir

Previous authors observed the influence of temperature variations in movement of fishes and noticed better catches in bottom set nets during summer in Tungabhadra reservoir. The present account reports on similar observations in Gobindsagar reservoir.

Estimation of fish production from Hirakud reservoir

A suitable procedure based broadly on stratified random sampling for estimation of fish production from Hirakud reservoir is described. The total fish production for the years 1978 and 1979 from Hirakud reservoir, along with seasonal variation of different species is discussed.

Fishing experiments with frame nets in Hirakud reservoir, Orissa

Experiments conducted with frame nets of sizes 1.0 m, 1.25 m 1.5 m, 1.75 m and 2.0 m in Hirakud reservoir showed that the net with 1.75 m frame gave the highest catches.

A note on the comparative catch efficiency of nylon over cotton gill nets in reservoir fishing

The authors conducted a series of experiments to evaluate the relative efficiency of nylon over cotton in tropical waters, particularly in reservoir fishing. The experiments were conducted in the Gobindsagar reservoir (Himachal Pradesh/Punjab). The nets made with both materials were identical in essential details like twine size, mesh size, number of floats arid sinkers and hanging coefficients.

Exploratory fishing experiments in Hirakud reservoir - Orissa State (1967-70)

Suitable areas for fishing have been located in the middle and upper regions of the Mahanadi course of Hirakud reservoir. In the former the suitable period is during summer and beginning of monsoons, and in the latter in summer and winter months. The fishery of the reservoir is contributed by four species namely S. silondia, L. fimbriatus, C. mirgala and C. catla.

Note on an abnormal catch of Catla catla in Hirakud reservoir

During the 1973 experimental fishing operations in the Hirakud Reservoir, it was found that though 11 species of fish occur in the reservoir only four species (Silondia silondia, Labeo fimbriatus, Cirrhina mrigala and Catla catla) predominate the catch in the order of abundance. This paper gives details of fishing operations and gears utilised.

Productivity and seasonal abundance of commercially important fishes of Gobindsagar Reservoir

Fishing experiments with gill nets were carried out at different centres of Gobindsagar reservoir through the years 1964-70. The seasonal abundance of main species of fishes and their zone of distribution were studied. Labeo diplostoma, Labeo bata, Barbus tor and Mystus seenghala are the main fish species of the reservoir. The abundance of the above species were observed to be the highest towards the Lunkhar arm of the reservoir.

Coloured gill nets for reservoir fishing

Experimental fishing with different coloured nets has shown that white net yields better catch. The efficiency of the coloured nets was in the order yellow, grey, green and blue. Though there is little evidence to show some species preference to a particular colour, the results were not conclusive as the analysis of variance indicated that interaction between species and colour is significant only at 5% level.

Experimental trawling in Hirakud reservoir

Results of trawl fishing experiments conducted in Hirakud reservoir are discussed. Trawling has been found to be efficient than conventional gear in removing predators and trash fishes especially of the bottom. This method can be of much help in controlling the proliferation of such fishes in many Indian reservoirs.