FORTY-FOURTH BIENNIAL REPORT 



61 



tion of this fishery in California is not being proposed, 

 for the present. 



Five-Way Study 



Studies on sablefish were made by California, Ore- 

 gon, Washington, Canada, and Alaska. Additional data 

 w as supplied by the International Pacific Halibut Com- 

 mission. The work was coordinated by the Pacific 

 Marine Fisheries Commission and culminated in the 

 publication of the Commission's Bulletin 3. The work 

 showed that the sablefish stocks are divided into sev- 

 eral diff'erent populations, that California's populations 

 appeared to be in good condition but that some of 

 those farther north were not. 



Boat catch studies conducted since the publication 

 of Bulletin 3 have indicated that California's sablefish 

 stocks are still in good condition. 



RESEARCH VESSELS 



During the biennium the N. B. Scofield completed 

 nine cruises in 412 operating days. These cruises cov- 

 ered the coast between \'ancouver Island, British Co- 

 lumbia and the Gulf of Panama and offshore to the 

 Galapagos Islands on the equator. The vessel also 

 w orked as much as 500 miles offshore from Southern 

 California. 



Three trips were made into the waters off Mexico, 

 and Central and South America to investigate sub- 

 surface populations of yellowfin tuna by means of 

 long-line gear. Two other cruises, in which long-line 

 gear was used, were made oft" the Pacific Coast to 

 determine the albacore's migratory routes. 



Three trips utilized trawl gear, two to investigate 

 flatfish populations in the Northern California area 

 and one to carry out exploratory work on shrimp off 

 Central California. A cruise was conducted in South- 

 ern California waters to tag and release abalones. 



Yellowfin 



The Yello\\fin completed 18 cruises during the 

 biennium in 411 days of operations. All but two of 

 these cruises were made to carry out pelagic fish 

 investigations on the commercially important sardines, 

 anchovies and mackerel. For the most part these in- 

 vestigations were made in the coastal waters of Cali- 

 fornia and Baja California, between San Francisco and 

 Alagdalena Bay. 



Yellowtail and ahalone tagging were accomplished 

 on the two "nonpelagic fish" trips. Pioneer experi- 

 mental work in the development of electro-fishing 

 collection devices were conducted aboard the vessel 

 with excellent results. Fish were positively attracted 

 from relatively long distances in salt water, presaging 

 the advent of more efficient operation in marine 

 surveys. 



In Ma>% 1956, extensive dry rot was found through- 

 out the Yelloivfin, rendering the vessel unsafe for fur- 



ther offshore biological research. It was removed from 

 offshore service and preparation made to decommis- 

 sion and replace it. 



Mo/lusk 



The 26-foot diving boat Mollusk is designed for 

 working close to rocks in shallow water where it can 

 operate in rock\- areas which would result in the 

 destruction of less maneuverable craft. The boat has 

 been used exclusively in the abalone investigation. 

 Equipped w ith compressor, diving stage and ladder, 

 deep sea diving equipment, hose and underwater tele- 

 phone, it enables department personnel to work in 

 comparative safety while conducting underwater sur- 

 veys and operations. 



Nautilus 



The primary function of the NmitUiis has been that 

 of mothership and base operations for the abalone 

 investigation. Because the Mollusk is small and has no 

 accommodations to sleep or feed the necessary crew, 

 the 50-foot Nautilus goes along whenever the investi- 

 gation is so far from a port that it is not practical to 

 return to harbor each evening. 



The Nautilus is equipped with an electrical gener- 

 ating s\stem which is used to supply the power for 

 underwater lights used by personnel in the study of 

 night time habits of abalone and for underwater pho- 

 tography. Occasionally, aqualung diving is conducted 

 from the Nautilus but for the major portion of the 

 underwater work conventional diving gear is used. 



The Nautilus is well equipped for other investiga- 

 tional work and during the biennium was used in the 

 following investigations: 



Herring: The herring schools in San Francisco Bay 

 were charted with the electronic underwater gear. 

 Gillnets and blanket nets were used in sampling the 

 herring schools. 



Crab: Experimental crab traps were used to test the 

 effectiveness of different sized escape openings for 

 releasing undersized crabs. Beam trawls were used to 

 collect crabs in the very small sizes. 



Shrimp and Prawn: Shrimp surveys and some ex- 

 perimental fishing with prawn traps were carried on 

 from the Nautibis. 



Survey vesse/ N B. Scofield h designed for use wifh many types of gear. 



(Photo by Claude M. Krcider) 



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