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IV. B. Current Research Efforts 



IV.B.l. Research Conducted by SWFC 



Research efforts in 1980 were directed toward: 1) 

 assessment of the stock using conventional techniques such as cohort, 

 yield-per-recruit, and spawner/recruitment analyses, and 2) development of 

 a fishery/environment simulation model intended to describe mathematically 

 the fish- fishery interaction and test hypotheses on the effects of 

 management actions on the stock. This model is also intended to guide 

 future research. Additional research efforts are being conducted by the 

 Albacore Fisheries Investigation in the Coastal Fisheries Resources 

 Division of the SWFC, La Jolla. 



A1 bacore Oceanography Research --This research is 

 designed to gain understanding of the environmental effects on albacore 

 distribution, availability, migration, vulnerability, and possible 

 abundance. The goal of the research is to develop quantifiable indices of 

 key environmental processes that may be used in fish/fishery/environment 

 models for use in providing advice for eventual international management of 

 the North Pacific albacore resource. Specific studies include 1) the 

 influence of North Pacific Transition Zone frontal structure on albacore 

 migration, distribution, and availability, with studies being conducted 

 using data from research cruises, cooperating fishing vessels through joint 

 studies with AFRF and others, and historical data files; 2) acoustic 

 tracking studies to determine albacore depth distribution and optimal ocean 

 temperature relationships that may affect availability and vulnerability; 

 3) the influence of coastal upwelling on availability and vulnerability, 

 using fishery data from logbooks and upwelling indices from PEG; 4) 

 satellite-oceanography studies to evaluate the use of ocean measurements 

 made from space to monitor key oceanographic conditions that influence 

 albacore distribution, migration, and availability; and 5) the development 

 of indices of environmental conditions affecting albacore for use in 

 fish/fishery/environment models, using historical data bases and data from 

 research vessels and cooperating fishery vessels. 



Albacore Biology Research --The objective of this 

 research is to gain knowledge and understanding of selected areas of 

 albacore biology for use in albacore oceanography research and population 

 assessment studies. Specific research areas include: 



1) Age and Growth Studies- -These are being conducted using 

 albacore tag release and recovery data from the coopera- 

 tive NMFS/AFRF albacore tagging program, and the otolith 

 daily ring increment method of ageing fish. The latter, 

 which is part of the tagging program, involves a field/ 

 laboratory study to evaluate the rate of otolith ring for- 

 mation in albacore, using injection of tetracycline to 

 "mark" otoliths at time of release of tagged albacore. In 

 addition, a study is being conducted in cooperation with 



