Preservation of cotton fish net twines by tanning 2. Fixation of tannin

Fixative behaviour of tannin belonging to three functional groups was stud1ed m deta1l using copper sulphate and potassium dichromate as oxidising agents.

Utilization of treated wood, steel, fibreglass, ferrocement and aluminium in the construction of modern fishing boats and their comparative cost analysis

Modern fishing boats have to be built not only on perfect lines but also with sound and strong construction materials that will ensure a long lasting trouble free service commensurate with the heavy capital investment involved. Choice of construction materials for fishing boats need careful scrutiny as they have to perform too well under most aggressive environments-sea-water and marine atmosphere. A number of alternative boat-building materials are now available whose comparative merits and demerits as well as comparative costs are brought out in this paper.

Utilization of sardines

Oil sardine Sardinella longiceps stands out as the single largest pelagic fishery in India contributing to about 30% of total marine fish landings. Commensurate with the volume of the fishery, efforts at proper utilization of the fish by processing into canned and frozen products or by distributing in fresh state to internal consuming centres by quick transport have remained rather very poor. The paper presents the problems and prospects with regard to the utilization of the fish on the above lines. Results of investigations made at C.I.F.T. on the utilization of sardine body oil into industrially useful products such as factice, vehicle for paints, additive in lubricating oil and base for printing ink have also been discussed.

Effect of weight of otter boards on the horizontal opening of trawl nets

The paper gives briefly the experiments carried out to determine the optimum weight of otter board that should be used for a trawl gear for better efficiency.

Ecology and production in two sandy beaches of Goa. Part (A) Distribution of bacteria in Colva and Siridaon in relation to certain environmental parameters

Qualitative and quantitative studies on the bacterial flora of two beaches viz., Colva and Siridaon at high tide, mid-tide and low tide levels during the pre-monsoon period were made. Estimations of important nutrients, like inorganic phosphates and nitrates and organic carbon have been made and correlation with the bacterial counts is being attempted. Definite correlation between bacterial population and organic carbon is seen however, no correlation is observed between bacterial counts and other physicochemical parameters.

Observations on the fouling characteristics of four bryozoans in Cochin harbour

The occurrence of the four species of bryozoans under study showed that Electra crustulenta PALLAS and Victorella pavida KENT are brackish water forms, Electra bengalensis stoliczka and Schizoporella cochinensis Menon and Nair are typical marine forms. It is interesting to note the seasonal succession of these species in Cochin harbour correspond to the distribution of salinity in this area.

Faecal streptococci in fresh frozen shrimp

Present limit of faecal streptococci as 100/g in fresh frozen shrimp was found to be too strict a standard commercially prepared products. Statistical analysis of the data collected indicates that fixing the maximum permissible limit as 1000/g will be a more workable proposition.

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.

On the design, operation and efficiency of 11 m dual purpose trawl for small machanised [i.e. mechanised] boats

Preliminary midwater fishing trials were conducted off Cochin with an 11m dual purpose trawl during the monsoon months when the prawns were available in the column layers. Further, with a view to assess its suitability as bottom trawl, the gear with suitable modifications in the rigging was towed in comparison with a 15m bottom trawl along the depth ranges of 5-10m and 10-20m and the fishing operations were found satisfactory.

Quality tolerances for water for use in fish processing

A survey on the sources and quality of water used in prawn processing factories has revealed much non-uniformity in the chemical quality. An attempt has been made to study the effect of varying concentrations of chemical constituents in the water used for prawn freezing and its influence on the quality of the prawn after freezing and during cold storage. The results of the study are reported in this communication, together with recommendations on the quality tolerances for water used in fish processing industry.

Development of trawling in India

Of the three main methods of capturing fish, namely luring, attacking and snaring, the last mentioned has hitherto proved to be relatively more effective and apparently yielded better returns. Trawling falls under this method. The trawl is an economic gear, in terms of investment and yield, even in spite of the fact that the total trawl catches come only second to that of the seines. Commercial trawling in Indian seas is of recent origin and seems to have been initially introduced for the purpose of ground resources survey.

Biochemical investigations on the edible molluscs of Kerala 2. A study on the nutritional value of some gastropods and cephalopods

Data on the biochemical composition and food value of the edible portions of two gastropods, Pila virens and Achatina fulica and two cephalopods, Sepiella inermis and Loigo indica have been presented. These molluscs possess nutritive meat very rich in protein and minerals, which compare favourably with popular food fishes in caloric value. The significance of the variations met with in the biochemical constituents of the different species has been discussed.

On the results of bottom-drift-long-lines operated off Veraval with particular reference to selective action of baits and hooks used

Hither to comprehensive data on the various types of baits used for capture of predatory fish and selective action of different hooks for bottom-drift-long lines is conspicuous by its absence. In the present studies attempts were made to evaluate the effectiveness of three types of baits and four sizes of hooks. Significant results obtained during the course of these investigations are presented in this communication.

Experimental preservation of sardines (Sardinella longiceps), using Chlortetracycline

Effects of dips in 10 and 50 ppm Chlortetracycline solution on the storage-life of sardines in ice have been studied. 5 ppm-CTC-ice in conjunction with dip in 10 ppm CTC-solution has also been tried. CTC-treatment considerably reduced bacterial number and gave a better appearance to the fish. The high fat content in sardines resulted in rapid development of rancidity. CTC has been found to have no control on the development of rancidity. Hence, CTC treatment of sardines is found to be of limited advantage in extending the storage-life of the fish in ice.

Eradication of predatory fishes in fish ponds and nursery ponds using electricity

Prior to stocking economic species in tanks and nursery ponds, all the unwanted and predatory fishes in them will have to be removed. Even though most of them can be caught with ordinary gear such as cast net, drag net, scoop net etc. Total or absolute eradication is not possible and those left over are sufficient to destroy all the fingerlings introduced. Development of an electrical method for killing predatory fishes at reasonable cost is therefore, expected to provide a solution. This paper deals with a few methods, based on the use of electricity and which are suitable for different ponds.