ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00816.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThis paper presents some characteristics (length, weight and age) of adult Atlantic salmon in rivers of Brittany.The data were derived from 1,578 fish caught mainly by rod and line; the remainder being from net catches in estuaries and small samples taken outside the fishing season.The bulk of the fish spent 1 or 2 years in freshwater before smoltifying. Those fish becoming smolts at the end of 1 year were the most numerous (54%). The majority of the fish sampled were spring fish (82.4%). Very few summer fish were identified and those found were mainly grilse. The high proportion of spring fish in the sample is due to the high proportion of rod‐caught fish. Probably a complete census over the year would show a larger proportion of grilse and summer fish as these are not subject to heavy rod‐fishing the season being closed at the beginning of June.The relationship between sea age and river age and the influence of freshwater life upon the sea life were tested in four rivers. It seems probable that sea life depends chiefly on the river and the year of smoltification rather than on the freshwater stage.The biometric characteristics of Brittany salmon were compared with data from some foreign rivers.The angling exploitation of the spring Atlantic salmon in Brittany and the lack of data about summer migrations are discussed in regard to the future of this st

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00817.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe practical problems encountered by the Severn Trent Water Authority in setting up a cage rearing unit on a water supply reservoir are described. Rearing trials with rainbow trout and brown trout were undertaken over a two‐year period.The results indicate that a higher stock density of fish per unit volume can be held in a cage than at an available fish farm. Feeding techniques and general management methods are discussed as food conversion ratios are approximately twice those at the fish farm, with growth and survival rates slightly lower. The capital and operating costs are considered to be less expensive than those for setting up a land based operation. A credit on total expenditure is recorded on a twenty year cash/flow analysis, with contrasted operating costs of £1,340 per tonne of rainbow trout produced at the cages and £1,562 at the fish f

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00818.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe Brokopondo reservoir is situated in north‐east Surinam and has a surface area of 150,000 ha. The dam was completed in 1964 for providing hydroelectric power. During the filling stage of the reservoir. 1964–1967, the composition of the fish fauna was studied. From 1967 to the present, no fishery research has been carried out in the reservoir. The aim of a mission, which was conducted in December 1978, was to obtain fundamental information on the fishery potential and fish fauna. Thirty‐seven species have been collected with various fishing techniques; of these the characidSerrasalmus rhambeus(Linnaeus, 1766) and the cichlidCichla ocellarisBlock&Schneider, 1801 are possibly exploitable. The potential yeild of the reservoir is estimated at 3500 tonne yr‐1. Gill nets with large mesh sizes proved to give the best results of the different fishery techniques tried. A comparison of the recent ichthyofauna with the fish species composition during 1966–1967 is provided and

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00819.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTSalmon catch and effort data for 1977 from ten private fisheries on the River Wye are analysed and discussed. The 555 salmon caught represent 10.7% of the total Wye rod catch and the mean angling success rate of 0.045 ± 0.022 salmon per angler‐hour, equivalent to about 22 h per salmon, compares favourably with that for other rivers in Britain and Canada. Over 75% of all salmon caught were 2 sea‐winter fish, the age distribution of salmon caught in the sample being similar to those for the whole river. Angling success in the upper reaches during July and August may have been reduced by limited availability affected by water temperatures too high for migration, Flows most suitable for successful angling in each fishery are compared in relation to distance from the estuary and long‐term average daily flows. Salmon appeared to be caught nearer the crest of a spate in the upper compared with the lower reaches of the river and this difference is dis

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00820.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00821.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Book reviewed in this articles:Advances in AquacultureEdited by: T. V. R. PILLAY and W. A. DILL.The Complete Freshwater Fishes of the British IslesBy JONATHAN NEWDICK. A.&C.A Key to the British Freshwater LeechesJ. M. ELLIOTT and K. H. MANN.ReservoirsBy BRIAN HENDERSON‐SELLERS.TroutBy ERNEST SCHWIEBE

ISSN:1355-557X    

DOI:10.1111/j.1365-2109.1980.tb00822.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY