Belly depth studies for shrimp trawls - Part III

Earlier investigations with 13.69 m (45') four seam shrimp trawl indicated the optimum depth of belly to be 70 meshes. Present communication details further experiments on similar lines with a bigger shrimp trawl of size 17.07 m (56') without overhang. The results obtained have not only given corroborating evidence in support of the earlier findings but also helped in arriving at a relationship that for a given stretched width of belly ‘L’ the stretched depth of belly could be either 2L/5 or 40% of ‘L’ with an allowance of ± 2 meshes.

Studies on arsenical creosote as a wood preservative for marine structures. Part 1. Incorporation of arsenic in creosote at various temperatures

A detailed study of the fortification of normal creosote and low temperature creosote with As sub(2) O sub(3) at 40°C, 50°C, 60°C, 70°C, 80°C and 90°C was carried out. When compared to normal creosote, low temperature creosote has been found to combine more easily with As sub(2) O sub(3) when temperature was . raised from 40 to 90°C. The incorporated arsenic values obtained shows that low temperature creosote with high phenolic content, retains considerably more As sub(2) O sub(3) and a maximum of 0.2180% w/w can be incorporated in low temperature creosote at 90°C.

Studies on arsenical creosote as a wood preservative for marine structures. Part 2. Observation on leaching, corrosion and resistance to borer attack

A detailed study on arsenical creosote with reference to leaching, corrosion and anti-borer properties was carried out. Results showed that aging had very little effect on the preservative which suggested better fixation of the preservative into the wood. Corrosion of mild steel, galvanised iron, aluminium-magnesium alloy (M57S) and copper panels in the preservative was found to be negligible. Normal creosote and low temperature creosote of Regional Research Laboratory, Hyderabad, both fortified with arsenic trioxide resisted borer damage on wooden panels for a period of over five months in the port of Cochin. The performance of low temperature creosote fortified with arsenic was found to be equally satisfactory when compared to normal creosote fortified in the same manner. A loading of 208.6 Kgs/ml³ for Haldu (Adina cordifolia) and 138 Kgs/m³ for Mango (Mangifera indica) in the case of normal creosote and 177 Kgs/m³ for Mango the case of RRL creosote were found to be sufficient for treating the wood.

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.

Freeze drying of fishery products: Part IV - Biochemical changes occurring in prawn muscle during freezing, freeze drying and prolonged storage of the freeze dried product

The changes occurring in water and salt extractable protein and non-protein fractions in prawn muscle of different species during freezing, freeze drying and subsequent prolonged storage have been studied. There is no denaturation of water extractable proteins, whereas salt extractable proteins were rendered insoluble to the extent of 21% due to freeze drying. The freeze dried products remained in good edible condition for 32 months of storage up to which storage characteristics were followed.

Freeze drying of fishery products: Part V - Storage characteristics of ready-to-serve freeze dried foods

Behaviour of freeze dried ready-to-serve fish based food preparations during prolonged storage at room temp has been studied and reported in this paper. Storage life of such products under the conditions employed in this study can be reckoned in years at our ambient temps.

Shore seines for reservoirs - Part 1 - Design and performance

Based on the studies to introduce active gears in reservoirs, a prototype shore seine was designed and tested, the details of which are presented in this communication. The results revealed that the operation of this gear could effectively control the proliferation of under-exploited species.

Shore seines for reservoirs - Part 2 - Studies on optimum mesh size

Fish landings by shore seines operated in the Hirakud reservoir were analysed species wise and their morphometrical details were recorded. Based on the above investigation proportionality coefficients in respect of important species of fish were worked out in order to detetmine the optimum mesh size as this was important from the conservation point of view. This communication discusses the significance of mesh regulation for shore seines.

Preservation of Sardinella longiceps in iced and chilled seawater. Part 1 - Changes during storage with particular reference to bacterial load and nitrogenous compounds

Oil sardines in prime condition were subjected to onboard chilling. Two lots were chilled in CSW (samples C and CI), a third lot was chilled in crushed ice (sample I) and a fourth lot left not iced on deck (Sample AI). Upon landing sample AI was iced and sample CI was removed from the CSW and iced. All the four samples were kept in a chilled room for storage studies. The fish chilled and stored in CSW recorded the least, and the fish subjected to delayed icing, the highest values for all the indices of spoilage namely, free amino nitrogen, trimethylamine (TMA) and total volatile base nitrogen (TVBN). The total psychrophilic bacterial number also showed a similar trend. The organoleptic assessment of the cooked samples revealed C I, CI, AI to be the order of preference throughout the storage. This assessment was found to hold good for the rest of the parameters as well. The CSW held fishes were found to be distinctly superior to the iced ones for the first five days of storage. Such a marked prevalence in quality for five days would suffice for the fish to fetch a premium in the market over other landings of the same fish whether chilled or not chilled. Chilling on board in CSW and icing the same after landings, did not show encouraging results.

Preservation of Indian oil sardine (Sardinella longiceps) in iced and chilled seawater. Part 2 - Changes during storage with particular reference to salt penetration and lipid deterioration during CSW holding

Oil sardines in prime condition were chilled on board. Two lots were chilled in CSW (samples C & CI), one lot ice (sample I) and a fourth lot was left un-iced on deck (sample AI). Sample AI was iced after landing and sample CI was taken out of the chilled seawater and. iced. All the four samples were kept in a chilled room for storage studies. Sample C, chilled and stored in CSW, recorded a gradual gain in weight and an increase in salt content of the muscle. Presence of salt did not seem to cause any excessive protein denaturation. Salt extractability decreased at a gradual rate in all cases. Presence of salt seemed to wield no noticeable influence on lipid hydrolysis and subsequent peroxidation. Results of chemical and sensory evaluations highlight this. Holding sardines in CSW gave a product of excellent quality for the first four to five days of storage. Beyond the fifth day of storage quality deteriorated rapidly and there was no noticeable superiority for this sample (sample C) over the on board iced fish. This was evident in the sensory evaluation as well. However, a storage life of five days in a readily acceptable state is sufficient for the fish to be disposed in the market at a premium sale price over other landings of the same species.

Import substitution of combination wire rope. Part 1. Design, production and evaluation of a prototype combination wire rope

Model combination wire ropes with different covering materials were prepared and worked out specification for the prototype. A table model hand operated wire rope twisting machine was also developed for this. Prototype combination wire rope was twisted in collaboration with M/s South India Wire Ropes Ltd., Alwaye. Specification details, properties and field performance of the prototype studied are reported.

Import substitution of combination wire rope. Part 2. Production and standardisation of 17 mm dia combination wire rope.

The prototype combination wire rope (Cift-CWR 1) developed for deep sea trawling was further studied for improvement, optimisation of efficiency and standardization. A series of improved prototype combination wire ropes (Cift-CWR 2 to 6) were twisted and evaluated their mechanical properties and reported in this paper with recommendations for a standard 17mm dia combination wire rope of 6S (7C+8+1 Scr) + 6 Crs(6+1+1 Crc) construction.

Import substitution of combination wire rope. Part 3: Comparison of standard Cift-CWR and imported combination wire rope

Tensile and extension properties of standard Cift-CWR and imported combination wire ropes from Japan, Norway and Denmark are studied and the analysis is presented in the paper. Tensile and chemical properties of steel wire, tensile and abrasive properties of PP covering, effect of twist on material at different stages are worked out and reported.

An illustrated key to the Malacostraca (Crustacea) of the northern Arabian Sea. Part 6: Decapoda anomura

The key deals with the Decapoda, Anomura of the northern Arabian Sea, belonging to 3 super-families, 10 families, 32 genera and 104 species. With few exceptions, each species is accompanied by illustrations of taxonomic importance; its first reporter is referenced, supplemented by a subsequent record from the area. Necessary schematic diagrams explaining terminologies are also included.