Ashburn (Dart catchment) fisheries survey 1978

This is the Ashburn (Dart catchment) fisheries survey 1978 report produced by South West Water Authority in 1978. This report focuses on an exploratory survey to determine the population and distribution of all fish species and in particular salmonid species of the Ashburn stream. This survey is primarily intended for future reference on completion of the proposed Flood Alleviation Scheme of the Ashburn where it passes through the centre of Ashburton. Three sections were electro fished using D.C. Current Sections were chosen as easily accessible and through their relation in position to the intended scheme.

River Avon (including Glazebrook) fisheries survey 1978

This is the River Avon (including Glazebrook) fisheries survey 1978 report produced by South West Water Authority in 1978. This report aims to determine the penetration of Salmon into the River Avon system and to a lesser degree estimate the population of resident salmonids and other indigenous species. Six sections were electro fished at accessible points as detailed below. All fish were identified and measured. Each section was fished through three times to take the majority of the resident species. Small specimens of salmonid fry, eels and lamprey were common in almost all River Avon sections with the exception of Shipley bridge and Avon Dam but due to the mesh size of the standard dip nets used, many slipped through making accurate number estimation impossible.

River Bovey (main Teign tributary) fisheries survey 1978

This is the River Bovey (main Teign tributary) fisheries survey 1978 report produced by South West Water Authority in 1978. The aim of this report is to confirm or disprove the presence of alien coarse fish species thought present in the Bovey system. A chosen site was electro fished using D.C. methods wading upstream. All fish taken were measured and identified. Since it was not possible to distinguish between the young parr stages of migratory and non migratory trout, all parr taken have been included under the heading of Brown trout whereas in fact some of these parr may become migratory later in their life cycle.

River Bray fisheries survey 1978-80

This is the River Bray fisheries survey 1978-80 report produced by South West Water Authority in 1981. This report aims to assess the possible effects of new abstraction conditions at Leahamford on the fish communities of the River Bray, surveys have been carried out in 1978, 197S and 1980. Field work was done in August and September each; year. Abstraction began in summer 1979. On the River Bray one site upstream and three downstream of Leahamford were chosen. One site on the River Mole was surveyed and is considered as a control site, being not directly affected by abstraction. The sketch map shows these sites in relation to Leahamford.

Trade of live brooders of the black tiger shrimp, Penaeus Monodon Fabricius 1978, at Visakhapatnam, Andhra Pradesh

The demand for brooders of Penaeus monodon by the hatcheries, which are solely dependant on wild brooders for their seed production, has resulted in a vigorous fishery and trade for this species, especially along the Visakhapatnam coast. More than three hundred brooders are brought in per day for trading during the peak landing season from December to March every year. The price of gravid brooders has been declining over the years but on an average is about Rs. 30,000 per brooder. The total length of male brooders ranged from 190 to 246 mm during the three years under study and for females it varied between 210 and 330 mm. A specialized methodology for transportation, storage and trade of P. monodon brooders has been evolved over the years at Visakhapatnam Fishing Harbour. Concentrated exploitation of brooders from the wild and presence of pathogens in them makes a strong case for development of specific pathogen free brooders and conservation of wild stock.

Experiments on the induced breeding of milkfish, Chanos chanos (Forsskal) in 1978

Results indicated that a female having eggs with an average diameter of < 0.7 mm did not respond well to the hormone injections.

Effects of gamma radiation and freezing on the chemical and sensory changes in shrimp Penaeus monodon (Fabricius, 1978)

Gamma radiation (3, 6 and 9 kGy) in combination with low temperature (-20°C) were applied to retain the quality and shelf-life of shrimp, Penaeus monodon for a longer period. The quality was assessed by monitoring the chemical (TVN, TMA) and sensory changes in irradiated and non-irradiated (control) samples. Among chemical indicators of spoilage, total volatile nitrogen (TVN) values for irradiated shrimps were found to be 2.26, 2.18 and 1.57 mg N/100g of sample at 3, 6 and 9 kGy respectively after 90 days whereas for non-irradiated samples it was found 2.45mg N/100 g of sample. Trimethylamine (TMA) value for non-irradiated samples after 90 days were found 2.30mg N/100 g sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 2.10, 2.08 and 1.98 mg N/100 g sample respectively. The sensory scores of control sample were gradually decreased with the progress of storage period. From this study, it was clear that gamma radiation in combination with low temperature showed shelf-life extension (90 days) in each dose of radiation used but during the use of 9 kGy radiation, P. monodon showed best quality.