Appendix B Temperate Tuna Forecast for 1968' 



The statements which follow constitute the eighth consecutive annual prediction to be issued for the 

 summer season albacore and bluefin tuna fisheries off the Pacific Coast. 



The merger of the former California Current Resources Laboratory and the Tuna Resources 

 Laboratory to form the Fishery -Oceanography Center (see August, 1967, issue of this publication) has 

 placed the former Tuna Forecasting Program as a project within a new Fishery-Oceanography Program. 

 Although the mandate of the new program is broader than previously, our staff has yet to realize 

 significant gains to date in either personnel or funds because of restrictions presently affecting Federal 

 activities. Nevertheless, advances during the past year were made in the areas of environmental 

 monitoring and prediction; these advances were in heat budget studies, the analysis of sea temperature 

 anomalies, and in the interpretation and apphcation of the wealth of data made available to us through 

 the cooperative data exchange program between the Fishery-Oceanography Center and the Naval 

 Weather Service's Fleet Numerical Weather Central at Monterey, California. 



Satisfactory measurement of biological aspects of the temperate tuna populations and the effects of 

 varying economic conditions has continued to lag far behind our progress in monitoring and 

 understanding the environment. No meaningful progress has been made on the estimation of year-class 

 strength, apparent fish abundance, and fishing effort for either albacore or bluefin tuna. 



Early subscribers to this publication should note that these 1 968 forecast statements are being made 

 about 3-4 weeks later than in previous years. The delay in issuance of our predictions arises from 

 experience accumulated during the past 8 years, which has shown that prediction techniques once 

 thought to be valid have not withstood the test of time satisfactorily. Our prediction techniques were 

 based upon the expected persistence of large-scale sea surface temperature anomaly patterns; 

 consequently, the offshore thermal trends observed in April of each year were assumed to persist at least 

 through the following month of July. Last year, this assumption failed: the abnormally cold conditions 

 observed in April, 1967, were the basis for our predicting a late, more southern fishery than in 1966. 

 Subsequently, intense early-summer warming completely overtook the previous cooling trend, and by 

 July 15, abnormally warm conditions were established in the Pacific Northwest and then persisted for 

 the remainder of the season. The albacore responded rapidly to these dynamic changes, producing 

 near-record catches off Oregon and Washington while California experienced very poor fishing. 



This experience dictates that we substantially alter our approach for the 1968 season. One major 

 change will be the temporary suspension of long-term quantitative landings and area forecasts. The 

 second major change will be to make heavier use of short-term projections of conditions based on 

 current information issued in the form of outlooks and occasional bulletins. These bulletins which 

 received highly favorable response last year, will include: changes in oceanographic and atmospheric 

 trends; changes in location of productive fishing areas; changes in total fishing effort; and other data that 

 are pertinent to the fishing community. As in previous years, the success of these operations necessarily 

 depends upon the input of first-hand information from the fishermen at sea, dock operators and 

 processors. Our staff continues to be hampered by a scarcity of timely information of this kind. 



ALBACORE TUNA 



Previous knowledge of the high correlation between catch and sea temperature, combined with an 

 8-year experience in observing and summarizing sea surface temperatures at 15 -day intervals from April 

 to October, provides us with the basis for depicting the shaded areas in Figure 1 The isotherm fields for 

 the first and second halves of July represent our long-term averages for each interval. The shaded areas 



Bureau of Commercial Fisheries, Department of the Interior, California Fishery Market News Monthly Summary, 

 Part II, Fishing Information, May 1968, pp. 1-5. 



11-71 



