FISHERY BULLETIN: VOL. 71, NO. 2 



along the southern edge of this tongue. Note 

 that three bait boats were also fishing this 

 same region. They reported scores of 245-387 

 fish per day, not much higher than the jig 

 boats which averaged 215 per day on 29 July, 

 and below the 400 fish averaged by jig boats 

 on 28 July. 



Infrared SST— 30 July 

 (Figure 9) 



The results of this SST flight show how 

 rapidly the surface conditions can change in 

 an area in 1 day. As a result of the onset 

 of northerly winds (see Figure 3), renewed 

 upwelling is now apparent along the coast 

 between Cape Lookout and Newport. Surface 

 temperatures near Newport were less than 

 10"C compared with 14 C on 29 July. More- 

 over, offshore temperatures were cooler on 

 the 30th than the 29th. and no 18 °C water 

 was found on 30 July. The cooler surface water 

 pro()ably resulted from mixing due to increased 

 wind stress. Note also the two separate areas 



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•oeSTRUCTION /. 



II' 



FiouRE 9. — Sea-surface temperatures and albacore catch 

 rates, 30 July 1970. See Figure 6 for explanation of 

 catch notation. 



of 16°C water along the southern flight lines. 

 Most of the fishing activity this day was 

 again located off the Columbia River. Catches 

 continued to decline, however, from an average 

 of 215 fish per boat on the 29th to only 65 

 fish per boat on the 30th. Best success on this 

 day (uj) to 17 fish/hr) was in the vicinity of 

 15.5 °C, blue water off the Columbia River. 



InfraredSST— 31 July 

 (Figure 10) 



Fishing success continued its decline on 

 31 July with no jig boats reporting catches 

 over 10 per hr and daily catches averaging 

 a meager 55 albacore. Two bait boats also 

 rei)orted low catches, 75 and 68 fish per day. 



Winds were again northerly (Figure 3) and 

 infrared coverage by the aircraft was inter- 

 mitted inshore because of the fijg along the 

 coast produced by cold, upwelled water. A 

 pool of cool (15°C), green water was found 

 65 miles offshore about the same distance 

 offshore that the band of cooler water was 

 located on 30 July (Figure 9). 



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TTT 



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I I I I I 



•DESTRUCTION 



Figure 10. — Sea -surface temperatures and albacore 

 catch rates, 31 July 1970. See Figure 6 for explanation 

 of catch notation. 



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