ABSTRACTS OF PAPERS 



Alverson, Dayton L. 



Ocean temperatures and their relation- 

 ship to albacore tuna (Thunnus germo ) 

 distribution in waters off the coast of 

 the States of Oregon and Washington, 

 and the Province of British Columbia. 

 /Conference Paper V - Z.J ( See also 

 Alverson , Dayton L. 1961. Ocean 

 temperatures and their relationship to 

 albacore tuna (Thunnus germo) distri- 

 bution in waters off the coast of Ore- 

 gon, Washington, and British Colum- 

 bia. Journal of the Fisheries Research 

 Board of Canada, vol. 18, no. 6, 

 p. 1145-1152. ) 



Commercial albacore fishing offshore 

 from Pacific Northwest States and the Province 

 of British Columbia occurs during summer 

 months when offshore surface water tempera- 

 tures exceed 58° F. Fishermen have established 

 58° F. surface temperature as an indicator of 

 "tuna water," and this rule -of -thumb relationship 

 for surface water temperatures and albacore has 

 generally been substantiated by past qualitative 

 observations made during albacore investiga- 

 tions. Catch-per-hour data are also in accord 

 with this general relationship. However, catch- 

 per-unit-effort data do not indicate as marked a 

 decline in availability at temperatures between 

 54° and 58° F. as might be interpreted from qual- 

 itative observations. With the exception of one 

 albacore caught by gill net in 1956, all albacore 

 have been taken in Bureau of Commercial Fish- 

 eries investigations where surface temperatures 

 exceeded 54° F. , and the highest catch rates 

 have been obtained between 58° and 61° F. As 

 the thermocline depth averages about 60 feet in 

 the summer months offshore from the Pacific 

 Northwest States and temperatures fall well be- 

 low 50° F. at the bottom of the thermocline, 

 albacore probably inhabit o n 1 y the overlying 

 (mixed layer) lens of warm oceanic water. Con- 

 centrations of albacore appear to occur along 

 the interface of the warm oceanic waters and the 

 cooler waters adjacent to the coast. 



Austin, Thomas S. , and Richard A. Barkley 



Use of oceanographic monitoring stations 

 in fishery research. /Conference 

 Paper V - 97 



With the support of data from monitoring 

 stations established by the Bureau of Commer- 

 cial Fisheries Biological Laboratory, Honolulu, 



a plea is made for the establishment of simi- 

 lar monitoring station programs by other 

 laboratories. 



Oceanographic studies in support of fish- 

 eries investigations should normally begin with 

 investigations of local midwinter and midsummer 

 conditions, which establish extreme conditions 

 at times of minimal rates of temporal change. 

 These studies should be followed by similar 

 broad-scale surveys, preferably synoptic, dur- 

 ing periods of transition. Later, the results of 

 these surveys lead to research on particular 

 features of the ocean thought to be ecologically 

 significant. At this point oceanographic studies 

 should progress from the stage of exploratory 

 surveys to the stage of research into mechanisms 

 and rates of change in the ocean, and conven- 

 tional surveys per se cease to be economical or 

 practical means for gathering data. Logically, 

 it is at this stage that monitoring stations be - 

 come most useful, in that they provide time- 

 series data at a series of points in space, making 

 it possible to determine rates and study proc- 

 esses. The final choice of sampling locations 

 for monitoring purposes will be determined by the 

 results of surveys, but it is a worthwhile risk 

 to establish monitoring stations in likely loca- 

 tions at the same time oceanographic surveys 

 themselves are begun, knowing that some sta - 

 tions may have to be relocated or discontinued 

 as knowledge accumulates, but that some will 

 provide data of interest for periods between 

 surveys and perhaps for indefinite periods 

 thereafter. 



Examples of the value of data from moni- 

 toring stations are given. A station established 

 at Koko Head, on Oahu, Hawaii, has been in 

 operation for over 7 years. Data from this sta- 

 tion are now used to predict the year-to-year 

 changes in the catch of the Hawaiian skipjack 

 fishery, a prediction which has been successful 

 for the past 4 years and has been applied to 

 accurately hindcast the catches for 7 previous 

 consecutive years. A station at Christmas Is- 

 land was established in 1954, in time to detect 

 precisely the time at which unusual cooling of 

 the surface waters occurred, during 1955, and 

 the details of a subsequent warming trend which 

 reached a maximum in the early winter of 1957. 

 More recently, a networkof monitoring stations, 

 including eight island stations and two weather 

 ships, has yielded evidence of coherent changes 

 in surface salinity over distances of many thou- 

 sands of miles in the central North Pacific 

 Ocean. 



