- Fish/Shellfish Research and Management
- Fish/Shellfish Research and Management -- Management and Conservation
Published: August 2002
The following tables are updated from the 1999 volume. An attempt has been made to standardize the sources and methods of computation. These are variable, depending to a large extent on the type and amount of biological work done in the past. The information since 1951 is more reliable than that for earlier periods. The format and information in tables are under constant revision to make the publication an accurate and valuable handbook for fishery workers.
Sources of Landing Statistics
Landing statistics for the earlier period were, whenever possible, published values from Craig and Hacker (1940), Cleaver (1951), Smith (1956), and FCO and WDF (1971). Commercial landing statistics since 1948 were obtained from tabulation of the combined Oregon and Washington fish receiving tickets provided to and returned by fish buyers. Recreational catch and effort statistics are obtained from sampling programs or tabulation of angler-returned catch records. Treaty Indian ceremonial and subsistence catches are provided by the tribes. The values that are preliminary are listed with parentheses in the tables.
Sources of Average Weight Values
The average weight values required to calculate numbers of fish landed from poundage records were obtained from several sources. During 1938-1950, constant values were used for Zones 1-5 and Zone 6. Between 1951 and 1956, the research staffs of WDF and FCO conducted a sampling program that included counts and corresponding weights of large numbers of salmon and steelhead by week of fishing and zone of landing. During 1957-1967, we calculated average weights for chinook and sockeye salmon from length-weight formulae for some seasons and most years. When neither length nor average weight data were collected, the most appropriate 1951-1956 overall average weights were used.
Since 1967, the average weight values required to calculate numbers of commercial fish landed from fish receiving tickets were obtained from weights of fish sampled randomly at various buyers.
Computation of Run Size and Escapement
The estimates of the size of upriver runs were obtained by adding the lower river landings to the appropriate Bonneville Dam counts. Beginning in 1980, various stocks of fall chinook, and, in 1981, various stocks of spring chinook, were estimated on the basis of CWT recoveries or GSI analyses, not timing of catches. The escapement is estimated by subtracting the treaty Indian landings from the count at Bonneville Dam.