49 research outputs found
The assessment of the flow requirements for upstream migration of salmonids in some rivers of North West England
This is the assessment of the flow requirements for upstream migration of salmonids in some rivers of North West England produced by the North West Water Authority in 1985. This report focuses on the automatic fish counters operating on the resistivity principle used for several years in North West England. This report aims to investigate the flow requirements for upstream migration of salmon and migratory trout. The data obtained confirmed that during summer months most fish movement occurs in the higher range of the available flows, but the migration flow range varied from year to year, depending on prevailing river levels. Of the other environmental variables measured, only water temperature and incident light intensity appear to have any direct association with fish movement. Information on migration flow ranges were used in conjunction with computer simulations of the effects of abstraction proposals on historical flows to assess the implications of these proposals for migratory fish
Episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystem, with particular reference to fish populations in N.W. England
This is the episodic variations in stream water chemistry associated with acid rainfall and run-off and the effect on aquatic ecosystems, with particular reference to fish populations in North West England produced by the North West Water Authority in 1985. This report looks at the biological, physical and chemical information collected over a five year period from over 100 sites on upland streams in the North West Region of which drained rocks of low buffering capacity. In both Lake District and South Pennine sites striking differences were found between the composition of invertebrate communities inhabiting acid-stressed and less acid-stressed streams. Electric fishing surveys showed that acidic streams (geometric mean pH <5.5) generally had abnormally low densities of salmonids ( < 0 .2m2) and that 0+ fish were very few or absent. The latter indicates recruitment failure. Salmon were more sensitive than trout to low pH
Conservation of the Irish pollan, Coregonus autumnalis pollan Thompson, in Lough Neagh, Northern Ireland
Restoration of riverine salmon habitats A guidance manual
Also called Fisheries technical manual no. 4Available from British Library Document Supply Centre-DSC:7218.47425(44) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Survival of Brown Trout (Salmo trutta L.) Stocked as Summerlings and Autumn Fingerlings in Two Northern Ireland Lakes
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Management of habitat for rehabilitation and enhancement of salmonid stocks
Factorial analysis of an experimental comparison of three methods of fishing for rainbow trout, Salmo gairdneri Richardson, in still water
Acidification of surface waters in Cumbria and the South Pennines
Final report to the Department of the EnvironmentSIGLEAvailable from British Library Document Supply Centre- DSC:OP/LG-5416 / BLDSC - British Library Document Supply CentreGBUnited Kingdo