VAN CLEVE and BEVAN: DECLINE OF KARLUK SALMON RUNS 



1500 



1500 



I I I I 

 I960 



Figure 3. — Total Karluk sockeye salmon returns from 

 each year's spawning computed from ages obtained from 

 samples taken at the weir. 1943-61. Both catch and es- 

 capement included. 



reduced to 76,834 in 1953 and to 21,000 in 1955. 

 Finally, fishing of Karluk sockeye salmon was 

 prohibited in 1971. Nevertheless the Karluk 

 weir count of about 143,000 sockeye salmon in 

 that year was the lowest on record. 



Beginning in 1950, the total number of fish 

 returning from each year's spawning increased, 

 reaching a high of about 1,100.000 from the 1957 

 spawning. Thereafter the returns fell. This is 

 shown on a different time scale in Figure 4 in 

 which the total run including both the spawning 

 escapement and catch are plotted. This shows a 

 decline in total Karluk run to a low point in 

 1956 with a subsequent rise to 1962 after which 

 the run declined again to the present. This figure 

 agrees with the former and also illustrates the 

 dominance of the 5-yr-old fish in the returns. 



As indicated above there are many causes of 

 the changes in size of the Karluk runs, but one 

 obvious factor must be the amount of fishing in 

 the Karluk area along the beach on either side 

 of the mouth of the Karluk River and about 1 

 mile offshore. The open fishing periods are plot- 

 ted in Figure 5 from 1941 through 1972 to show 



Figure 4. — Total Karluk sockeye salmon run, including 

 spawning escapement and catch for each year from 1950 

 to 1971. 



periods closed to fishing in June, July, August, 

 and September. 



The greatest numbers of consecutive closed 

 days were in the latter half of August and in 

 all of September in 1929, 1930, 1934, 1935, 

 1936, 1938, 1939, 1941, 1944, 1946, 1947, and 

 1949. None occurred in 1928 and 1931 and none 

 occurred in August in 1932, 1933. 1937, 1940, 

 1943, and after 1960. The period of 1928 to 1950 

 shows a declining run. From 1951 to 1957 the 

 Karluk run increased in total numbers of fish 

 returning from those spawning years as shown 

 in Figure 3 (i.e., from 1956 to 1962 in total size 

 of run in Figure 4). The primary difference be- 

 tween the fishing season in the years 1950 

 through 1956 and all other years is the in- 

 creased number of consecutive days of closure 

 shown in Figure 5, especially in August and 

 September in 1951 through 1956 and in July in 

 1951 through 1955. Beginning in 1956 escape- 

 ment was obtained by reducing the weekly fish- 

 ing time and increasing the length of weekly 

 closures except that closed periods of 12 to 34 

 days were used in 1965 and 1967, respectively. 

 In 1971 only 14,000 Karluk sockeye salmon were 

 taken from a total run of about 175,000 fish, so 

 that this method of control apparently was not 

 effective in arresting the decline in runs. 



641 



