Fishery forecasting- environmental prediction charts. 



G. Mattson 



After this prediction of cooler than normal water 

 was issued, the environmental monitoring system indica- 

 ted an unpredicted and anomalous warming of a very 

 large oceanic area to the north of California, due to ab- 

 normally liglit cloud cover and sliglrt winds over a great 

 part of the northeast Pacific Ocean. A bulletin was im- 

 mediately issued to the fishing community, warning that 

 the predicted trend had not materialized and that the 

 actual conditions were likely to result in a rapid move- 

 ment to the north of the main body of the migrating 

 albacore tuna population. Such a movement would 

 probably result in a bumper catch in the Oregon- 

 Washington area during the later part of the summer. 

 This prediction was realized, and that region experienced 

 its best albacore tuna season since 1944. The large land- 

 ings were in part due to the early warning received by the 

 fleet, to which a large number of the vessels responded. 

 Also, the arrival of the tuna in the area coincided with 

 spawning concentrations of saury, which tended to hold 

 them in the region of the fishery. California, on the 

 other hand, had a poor year and boats which, for one 

 reason or another remained there had an unprofitable 



season. 



Thus, two things were conclusively demonstrated 



during the summer of 1967: that the persistence of 

 large-scale ocean conditions more than 1 5 days ahead was 

 significantly more difficult to predict than had previously 

 supposed for this region, and that predictions for peri- 

 ods less than 15 days were of real value to the daily op- 

 erations of the fishing fleet. In addition, the 1967 ex- 

 periences had dictated that long-term forecasts of land- 

 ings and fishing areas should be temporarily suspended. 



to be replaced by heavier reliance on short-term bulletins 

 of predictions based on currently observed trends. 



Temperature anomaUes of sea surface from long-term 

 means: sliaded areas are negative anomalies. 



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