Sensitivity Analysis of the SDSU River Basin Model

The demand for water has increased continually in all parts of the world while the quantity available is essentially unchanged. Further, the projected increase in demand for different categories of use, particularly municipal consumption, manufacturing, mining and power generation will lead o a water shortage in the future. For example, by the year 2000 the effluent of municipal swage plants is expected in industrial wastes. The average annual streamflow that discharges into the ocean from the continental United States is essentially fixed and amounts to 1100 billion gallons of water per day. It is estimated that by the year 2000 withdrawals will total more than four fifths of this amount and the polluted return water will be about two thirds of the total streamflow. The awareness of the problem is highlighted by the establishment of the Office of Water Resources in the Department of Interior. From the research sponsored by this organization as well as others, there has been a substantial effort to improve management of water as a resource. Although the results of some research can be directly applied, the complex relations between the rivers and their basins necessitate a verification of the results on a hypothetical river basin before application to a real basin. An interdisciplinary team at the University of Missouri developed a computer model to relate the physical and economic aspects of the Blackwater River basin in central Missouri. One of the investigators of the Missouri team suggested that the Missouri model be modified for use on the Big Sioux River near Sioux Falls, South Dakota. The modification resulted in the development of the SDSU model

Technology upgradation in tuna fishery, diversification and changing pattern

Tuna and tuna-like fishes are under-exploited resources of Indian EEZ. Exploitation of oceanic tuna and billfishes are possible only by longlining and purse seining. Existing deep sea fishing vessels in India are mostly trawlers equipped for bottom trawling for shrimps and fishes. Most of them are stem trawlers and few are double riggers. Hence the deck layout is not suitable for either longlining or purse seining. Both longlining and purse seining for oceanic tuna and billfishes are specialized techniques which require special onboard facilities, deck layout and deck machineries like line haulers, chute, shooting and hauling accessories for longlining and special powerful purse winch, power block etc. for tuna piu'se seining

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

Development of trawls for medium sized trawlers for Veraval, north-west coast of India

Comparative fishing experiments with 25 m bulged belly and 25 m six seam trawls were carried out to study the relative efficiency of the gear. Bulged belly trawl was found more efficient than the other at depths below 40 m. The tension and horizontal opening were more in bulged belly and six seam trawl respectively. Bulged belly caught more of prawns and lobsters but there was no significant difference in the catch of sciaenids, cephalopods and ribbon fishes in the two nets

A new large mesh trawl for dermersal fishery

A new large mesh demersal trawl of 32 m head rope length is found more efficient for the exploitation of demersal fishes off Veraval. Increased catch with a proportionate increase of demersal fishes was obtained when compared to a standard bottom trawl of 32 m head rope length with small meshes, suggesting the possibility of increasing the mesh size of trawl nets in the forepart. This increases the mouth area of net which enhances the fishing power by covering a large area per tow. The net is simple in construction, easy to repair and maintain and fewer in the number of meshes

Purse-seines off Goa

The design, construction and operational details of the purse-seines operated from Goa, for sardines and mackerel are reported briefly. The deck equipment and details of vessel along with the fishing season, fishing grounds and catches are briefly accounted. The design has been compared with Japanese purse-seines operated for the same species of fishes. Based on the findings an improved design of purse-seine has been presented

Studies on the suitability of HDPE material for gill nets

The suitability of HDPE yarn and HDPE twine in place of nylon for gill nets has been studied. As regards total catch nylon gill net is found to be better than HDPE nets. However, statistical analysis of the catch in respect of quality fishes shows that HDPE yarn nets are equally efficient as nylon nets

A new high opening trawl for Veraval waters

The newly developed 25m high opening trawl possesses the properties of a high rising bottom trawl and a semi-pelagic trawl. The new gear is effective for the capture of demersal and semi-pelagic fishes. The net offered more horizontal opening and less resistance with significantly high catch of ribbon fish when compared with bulged belly trawl

Performance of 25m large mesh demersal trawl off Veraval, north west coast of India

Performance of a 25m large mesh demersal trawl, with 150mm mesh size in the fore parts of the trawl was evaluated in comparison with one boat high opening trawl of the Bay of Bengal Programme (BOBP) with 360 meshes of 160mm mesh size and 25.6m head rope length. An 8.2% increase in catch was obtained by 25m large mesh demersal trawl. The gear is comparatively cheaper, lighter in construction and offered better horizontal spread with significantly lower towing resistance. Commercial suitability of the gear for efficient harvesting of demersal fish resources of the region is discussed

A record of an unusually large specimen of Lactarius lactarius (Schneider)

A specimen of Lactarius lactarius (Schneider) measuring 350 mm in total length, the largest to be recorded so far, was caught off Veraval, northwest coast of India. The previous known record was that of a specimen measuring 330 mm in total length from Gulf of Mannar, southeast coast of India (Shanmughavelu 1973)