A Review of World Salmon Culture

World farmed salmon production reached 145,000 metric tons (t) in 1988 and an estimated 217,000 t in 1989. The latter figure is comparable to the U. S. annual salmon catch (about 250,000 t) and is approaching one-third the size of the world wild salmon catch (about 700,000 t). The rapid expansion of farmed salmon supplies in the late 1980's has led to sharp price decreases. Lower prices have forced some farmers out of business, but at the same time, a large number of farmers first began harvesting salmon on a commercial scale as the 1980's ended. Farmed salmon production could exceed 270,000 t in 1990.

Size-related Hooking Mortality of Incidentally Caught Chinook Salmon, Oncorhynchus tshawytscha

Mortality associated with the incidental catch and release by commercial trollers of two size classes of chinook salmon, Oncorhynchus tshawytscha, was assessed. Observed cumulative mortality 4-6 days after hooking was 18.3 percent for sublegal-sizefish « 66 cm FL) and 19.0 percent for legal-sizefish. Size of fish was not significantly related to mortality; however, when the results were combined with data from a previous experiment, there was a significant inverse relationship between fish length and mortality. Hooking mortality estimates calculated from tagging experiments and observed relative mortality of legal-and sublegal-size fish held in net pens, were used to derive a range for total hooking mortality of 22.0-26.4 percent for sublegal-size chinook salmon and 18.5-26.4 percent for legal-size chinook salmon.

River Dart Salmon Project. Summary of Phase I report.

This is the River Dart Salmon Project Summary of Phase I Report (2002) by the Westcountry Rivers Trust. The report contains sections on the introduction to Dart Salmon, factors affecting salmon numbers, salmon rod catch and salmon electro-fishing data, and a summary and discussion of the next phase. It also contains two tables with time series analysis on fry/parr numbers in representative section of the River Dart and figures with trends in fry/parrs numbers at juveniles electro-fishing sites. The section on salmon rod catch data includes trend analysis, cross-correlation of catches in different rivers and a general conclusion.

River Dart Salmon Project. Summary of Phase II report.

This is the River Dart Salmon Project Summary of Phase II Report (2002) by the Westcountry Rivers Trust. The report contains sections on the project introduction, methods, habitat utilisation (predicted densities) and distribution at Walla Brook, Swincombe and Strane, bio-monitoring of water chemistry and suggested action at local, catchment and research scale. The attached maps show spawing, fry and juveniles habitats in the lower or upper Walla Brook.

Salmon Scale Reading Investigation 1972

This is the Salmon Scale Reading Investigation from 1972 by Cornwall River Authority. The object of this investigation is to examine, by means of scale reading, the biology of age classes of the salmon populations of the River Tamar, River Tavy, River Lynher, River Fowey, River Camel and River Plym. It contains for each river the numbers of caught salmon, number of scales received and which were unreadable and percentages in each age group separately for net and rod caught. Length and weight frequency distribution histograms have been plotted to show the size distribution of the various sea age group.

Effects of water quality in Bassenthwaite Lake on anglers' catches of salmon and sea-trout in the River Derwent

This is the report on the Effects of Water Quality in the Bassenthwaite Lake on Anglers Catches of Salmon and Sea-trout in the River Derwent April 1993 by the Institute of Freshwater Ecology. An analysis of the catch statistics for salmon and sea-trout in the Rivers Derwent and Cocker was undertaken in relation to available information on the algal water quality in Bassenthwaite Lake to test the hypothesis that poor catch returns were associated with a deterioration of water quality within the lake. Analysis of the catch statistics failed to reveal any correlation between water quality and catch returns for either species of fish and it is concluded that any water deterioration in Bassenthwaite Lake has not caused any major damage to the salmon and sea trout fisheries of the Derwent/Cocker system. This conclusion is supported by the analysis of the Windermere/Leven and Crake system, where no correlation could be found between lake water quality and downstream catches of migratory salmonid fish. However, the possibility still exists and such an effect might be detected by further field work on the macroinvertebrates and on the composition of potential salmonid spawning in the area.

Salmon stocks and fisheries in England and Wales, 2001. Preliminary assessment prepared for ICES, April 2002

This report presents a preliminary assessment of the state of salmon stocks and fisheries in England and Wales in 2001 to assist ICES in providing scientific advice to NASCO and to provide early feedback to fishery managers and anglers. The chief indicators of the state o f salmon stocks are normally the catches taken by rod and net fisheries. However, in 2001 angling was affected by the outbreak of foot and mouth disease (FMD), which restricted angling opportunities and access to rod fisheries in many parts of the country for lengthy periods. It is impossible to quantify the impact that FMD had on rod catches, although these were undoubtedly significantly reduced; net fisheries were unaffected by FMD. The declared salmon catch for 2001 (including those fish released alive by anglers) is provisionally estimated at 209 tonnes, representing some 57,000 fish, and comprising 153 tonnes (-43,000 fish) by nets and fixed engines and 56 tonnes (-14,000 fish) by rods. For direct comparison with previous years, it should be noted that the declared catch prior to the issue of a second reminder was about 49 tonnes (see below). An estimated 26 tonnes (43%) of the rod catch was released alive. These figures do not take account of catches of salmon which go unreported (including those taken illegally), and it is estimated that there may have been a total of 33 tonnes of additional fish caught in 2001; approximately 15% of all fish killed.