dogfish fishery of the 1940's. Harrison and 

 Samson (1942) report that in the United States 

 shark livers were first used as a source 

 of vitamin A in 1936-37. California proc- 

 essors of sardine oils became interested in 

 fortifying biologically tested sardine oils with 

 low cost vitamin A. Dogfish livers were 

 found satisfactory, but soupfin shark livers, 

 yielding a very high-potency vitamin A, and 

 cheap vitamin-rich oils from Europe were 

 preferred. Unable to compete, the dogfish 

 fishery developed slowly until European 

 sources of liver oil were cut off with the 

 outbreak of World War 11. 



Demand for domestic oil sources during 

 the war led to technological advances in 

 extraction of vitamin A from oils. A process 

 was developed that made it economical to 

 concentrate vitamin A from oils of relatively 

 low vitamin potency (such as dogfish liver 

 oil). With European competition cut off and 

 with a means of competing with the higher 

 potency soupfin liver sources, the dogfish 

 fishery was given impetus necessary to de- 

 velop into a large-scale industry. Vitamin 

 oils from dogfish and soupfin sharks became 

 the major sources of vitamin A in the United 

 States and Canada. The processed oils were 

 used by pharmaceutical houses, food proc- 

 essors, and stock and poultry feed manu- 

 facturers (Holland, 1957). 



The dogfish fishery of the Pacific Northwest 

 built up rapidly to a peak in 1944, when almost 

 133 million pounds of whole fish were caught 

 between California and Alaska. In the 9 years, 

 1941-49 (table 1), annual catches exceeded 

 40 million pounds, and the cumulative catch 

 exceeded one-half billion pounds. 



The fishermen were paid for the livers at 

 a price dependent on vitamin potency. Aver- 

 age prices paid are shown in table 2. Excellent 

 prices, obtained by fishermen between 1944 

 and 1949, reached a high of 56.6 cents a 

 pound in 1948. 



During the early phases of the fishery, 

 the largest portion of the catch was taken on 

 longline gear in coastal waters, but otter 

 trawling and diver (sink) gill nets soon domi- 

 nated the fishing. Holland (1957) reports that 



"following 1941, the ocean fisheries became 

 the dominant source of dogfish caught by 

 Washington fishermen, producing between 64 

 and 79 percent of the total state's landings." 

 Otter trawl catches comprised from 63 to 89 

 percent of the catches from the offshore 

 grounds. 



Major grounds fished by Washington fisher- 

 men in the 1940's were in Puget Sound, in the 

 Gulf of Georgia, between Destruction Island 

 and Cape Flattery, on Swiftsure Bank, on 

 40-Mile Bank, and in Hecate Strait. Canadian 

 fishermen operated off lower Vancouver Island, 

 in inside waters east of Vancouver Island, 

 and in Hecate Strait. Most of the fish were 

 gutted at sea (except in California), and only 

 the livers were landed. The livers, stored in 

 5-gallon tins, were sometimes salted for 

 preservation. 



Since 1949 imports of dogfish oils (fig. 4) 

 and the production of synthetic vitamin oils 

 have sharply reduced the demand for dog- 

 fish livers and virtually eliminated the west 

 coast fishery. In recent years total landings 

 on the Pacific coast have amounted to only a 

 few million pounds annually. 



The Atlantic Fishery 



Dogfish have been used for human food in 

 Asiatic and European countries for many 

 years. A German trawl fishery, supplying 

 dogfish for human foods, existed in the North 

 Sea as early as 1906. In 1903 the English 

 government seriously considered a method of 

 eradicating or removing dogfish, which at 

 that time were considered a "scourge" to 

 other lucrative fisheries (Ford, 1921). The 

 government's solution was to encourage 

 capture through creation of a market for dog- 

 fish as a human food. Toward this end, the 

 government subsidized transportation costs 

 of dogfish, and a number of cookery experi- 

 ments were undertaken. Partial success was 

 achieved, and landings of dogfish increased 

 rapidly. 



On the east coast of the United States and 

 Canada similar attempts have been made to 

 encourage capture and develop markets for 

 dogfish. 



