Fisheries hydrography

The article is based on a talk given before a meeting of the Society of Fisheries Technologists, India

Studies on the biochemical composition of some freshwater fishes. Pt. 3. Ovary

Biochemical composition of the spent ovaries of 23 different species of freshwater fishes showed a much lower value for protein and fat with higher moisture content than those of the ripe eggs, suggesting an inverse relationship between fat and moisture. Ovaries during the recovering phase showed fairly high values of phosphorus, but lower than those for the ripe eggs. Higher values of calcium and iron in spent ovaries than those in ripe eggs probably suggest that there is a greater requirement of calcium and iron during the spent phase of the gonads

Studies on the biochemical composition of some freshwater fishes. Pt. 2. Liver

Although considerable work has been done on the composition of fish liver oils, most of which includes the study of various vitamins and fatty acids, little attention has been paid towards the composition of fish liver as a whole

Studies on the biochemical composition of some freshwater fishes. Pt. 1. Muscle

Twenty five different species belonging to 16 genera of freshwater fishes were analysed for protein, fat, moisture, ash, carbohydrate, phosphorus, calcium and total iron content in their muscle. Calorific value for protein, fat and carbohydrate fractions and total calories for each species were also calculated

Phytoplankton in a temperate-zone salt marsh: Net production and exchanges with coastal waters

Phytoplankton production and associated variables were measured in Flax Pond, a 52 ha salt marsh on the north shore of Long Island, New York, from July 1972 to October 1973. Measurements made up to five times per day, once per week, yielded a mean annual net primary production, determined by the 14 C technique, of 20.5 mg C/m 3 /h; daily means were as high as 60.0 mg C/m 3 /h. However, when productivity was calculated for the entire marsh ecosystem, the shallow water in the salt marsh produced only 11.7 g C/m 2 of marsh/year. There was a net flux of phytoplankton from the coastal waters into the marsh; during the summer up to 0.2 g chlorophy 11/m 2 of marsh was carried in with the tides daily and remained in the marsh. Analysis of the productivity data, as well as variables associated with productivity (pH, standing crop, nutrients, extinction coefficient), indicated that the aquatic portion of the marsh behaved more as a net consumer rather than a net producer of phytoplankton.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46630/1/227_2004_Article_BF00391561.pd

Aquaculture of green mussel <i>Mytilus viridis</i> L.: Cultivation on ropes from floating rafts

15-25M. viridis is a fairly widely distributed species along the coastline of India. In Goa, rich beds of this mussel are found in inshore waters and estuaries. Rope culture of green mussel in Goa has been started in 1974. Mussel seeds are transplanted from the natural bed at Velsao to Dona Paula, about 20 km away, and are allowed to grow on nylon ropes suspended from floating rafts. Environmental conditions both at Velsao and Dona Paula are almost similar. Growth of mussels on ropes is much faster than in natural beds. Mussels grow at a rate of about 8 mm/month on ropes and attain marketable size in approximately 5 months. The most difficult period for mussel culture is the monsoon season, when because of turbulent sea conditions, the rafts require constant attention. Total caloric content of cultured mussels is higher than those from the natural beds. Fouling of mussels on ropes by bryozoans and barnacles is common. Annual production of mussels is of the order of 23 kg mussel meat per rope or approximately 1150 kg of mussel meat per raft. In terms of yield in area, it works out to be 480 tonnes of mussels/ha/year approximately. Cost of production is about Rs. 2500/raft and the value of mussels produced is about Rs.6900. Rope culture thus gives high rate of returns of about 181%. Various constraints and advantages of mussel culture have been indicated and the potential of mussel farming in Goa has been compared with that of the other regions of the world where mussel culture is being practised. For the production of high quality protein food, mussel culture is perhaps the simplest and the easiest form of farming