Figure 4.- -Production of domestic dogfish and other 

 shark oils as related to imports. 



excellent prices continued through 1949, al- 

 though catches had fallen to less than 30 per- 

 cent of the record 1937-38 period. 



Landings in Oregon rose quickly in 1941-42 

 and reached a peak in 1943. The market de- 

 mand was good, and prices for shark livers 

 continued to rise until 1949 when $18 a pound 

 was paid for high-test (vitamin A) livers. The 

 catches did not follow the upward trend in 

 prices, but declined rapidly from 1942 on. 

 By 1946, total landings of soupfin shark 

 livers in Oregon had fallen to about 30 per- 

 cent of peak year landings. 



The trend in soupfin liver landings in 

 Oregon closely parallels the history of the 

 dogfish shark fishery. Together, the his- 

 tories of the dogfish and soupfin shark fish- 

 eries demonstrate that intense exploitation 

 can quickly reduce the cumulative stock levels 

 of these sharks. 



Concern for the dwindling number of dog- 

 fish and soupfin sharks was expressed as 

 early as 1943, and in October 1944 a meeting 

 was called in Victoria, British Columbia, to 

 consider the necessity of regulations and to 

 recommend methods of avoiding wasteful prac- 

 tices in exploiting soupfin and dogfish sharks. 



Biological Evidence of Stock 

 Reduction 



grounds. Statements by zoologists have also 

 pointed to a considerable reduction in cumu- 

 lative stock levels following development of 

 the fisheries in the 1940's. According to K, S. 

 Ketchen of the Fisheries Research Board of 

 Canada (personal conversation with the senior 

 author), dogfish became extremely scarce 

 on traditional British Columbia grounds by 

 1949. Holland (1957) noted that although the 

 average total landings of trawlers remained 

 fairly constant from 1941-46, fishing time 

 increased. He also observed a decrease in 

 the average catch per effort of longline. 



The Fisheries Research Board of Canada 

 studied changes in availability and abundance 

 of dogfish in Hecate Strait from 1943-46 by 

 examining tally slips or the fish receipts of 

 those fishermen that used sunken gill nets 

 during the May-October period (Barraclough, 

 1948). Catches in sink gill nets for boats 

 fishing in 1944, 1945, and 1946 were com- 

 pared monthly with catches from boats fish- 

 ing in 1943. Link relations were thus obtained. 

 Barraclough's data indicate a decline in avail- 

 ability of dogfish for each month compared, 

 except October, from 1943 through 1946. 



When the total yearly landings of dogfish 

 livers from the same boats were compared 

 (fig. 6), a reduction of 50 percent in relative 

 availability of dogfish was indicated. The 

 decrease, which occurred in 4 years, indi- 

 cates that a considerable reduction in cumu- 

 lative stock level, at least in a localized 



Fishermen have indicated that during tne 

 latter years of the fishery the availability of 

 dogfish was much reduced on known fishing 



Figure 5.- -Tota Handings of dogfish livers in Washington, 

 Oregon, California, British Columbia, and Alaska-- 



1940-59. 



