On the resources of demersal fishes for bottom trawling in inshore waters off Kakinada by small mechanised boats

An attempt is made to assess the available resources of demersal fishes for bottom trawling off Kakinada, in inshore waters. From the experimental fishing operation during 1964-66, the average catch per hour was 52.79 kg for 9.13 m (30') OAL mechanised boat. The catch composition was dominated by prawns and sciaenids forming 45% of the total catch. The average catch per trawling hour was more during the quarter April - June. An assessment on productive depth range has indicated that catch rate is increasing with increase in the depth of fishing.

The Gjerstad kiln: a combined hot and cold smoking kiln

A combined hot and cold smoking kiln has been constructed for use at Lake Turkana, Kenya. Used for cold smoking, the kiln's main advantages over the traditional kilns used in this area are its greater smoking capacity and lower firewood consumption. Having the option of using the same smoke house for cold and hot smoking reduces the total construction costs for an operator producing both types of smoke cured product. The hot smoking process was found to require markedly less firewood than cold smoking, a fact of considerable importance in desert or semi-desert areas with sparse vegetation.

High temperature processing of fish sausage 4. - Heat penetration study

An examination was made of the rate of penetration of heat into fish sausage during processing at 115.6°C. Findings showed processing for 24 minutes to bring about complete destruction of Clostridium botulinum. A processing time of 30 minutes destroys almost all spoilage-causing organisms, thus prolonging the shelf life of the products.

Reliability of Escherichia coli and faecal streptococci as indicators of Salmonella in frozen fishery products

The results obtained in the present study suggest that Escherichia coli and faecal streptococci are of little value as indicators of the possible presence of Salmonella in frozen fishery products.

Trophic State Index, morphoedaphic index and fish yield prediction in a sub-tropical lake, Manchar (Sindh), Pakistan

Limnological factors of a sub-tropical lake Manchar were studied on seasonal basis. The mean values of various parameters were: transparency, (secchi disc reading): 90.5 cm, Orthophosphate: 0.257 mg/l, TDS: 3310,5 mg/l, Conductivity: 5232 µs/l, Total Chlorophyll (Planktonic): 31.3 µg/l Planktonic biomass: 5466 µg/l. Trophic state index (TSI) was calculated by using Carlson's (1977) equations. Mean TSI for transparency was 61, while for orthophosphate and chlorophyll, it was 82 and 64 respectively. TSI values indicate advanced eutrophic state of Manchar Lake. Morphoedaphic index (MEI) was also calculated on seasonal basis. The mean values were, TDS: 1103, conductivity: 1744, alkalinity: 60, transparency: 29 and biomass (plankton dry weight): 1746. Fish yield prediction for Manchar Lake (Z =3m, mean area=100 km²) was calculated by using MEI values. The results were quite different among various parameters. Conductivity (89.1mt/y), biomass (67.6 mt/y) and TDS (44.6 mt/y) were found to be good predictors of fish yield. Chlorophyll, transparency and alkalinity values gave very low estimate.

Studies on the growth and production of six major and exotic carps in Nasti baor, Jhenaidah, Bangladesh

An investigation on growth, production and fishery of three Indian major carps: rohu, Labeo rohita, catla, Catla catla and mrigal, Cirrhinus mrigala and three exotic carps: silver carp, Hypophthalmichthys molitrix, grass carp, Ctenopharyngodon idella, and common carp, Cyprinus carpio was carried out in Nasti baor during February to April months. In catch per unit effort (CPUE) study the highest catch/day/person (3.13 kg) and catch/day/gear (40.65 kg) was recorded in the month of March for kochal fishing. In komar fishing catch/day/person (15.08 kg) and catch/day/gear (1206 kg) was also found higher in March. Komar fishing was done only in March and April and its CPUE was greater in both the months than that of kochal. The average recovery rate (combination of all six species) was 37.80 considering the stocking from July month of the previous year. The recovery rate of common carp (54.1) was the highest and lowest (13.90) in case of silver carp. When the recovery was calculated on the basis of one year data and stocking, it was 55.6%. Analysis of production model revealed that the present production (54,806 kg/year) is less than both theoretical production (model I- 85,285 kg/year and model II -75,952 kg/year) estimated. Therefore, it may be concluded that the fish production from Nasti baor could still be increased from the present level of production.