FISHERY BULLETIN: VOL. 71, NO. 2 



tribution of 421 special logs to fishermen in 

 Oregon, Washington, and California prior to 

 the 1969 albacore season. These logs were 

 unique in that they were designed to obtain 

 several entries per day from fishermen so that 

 variations of catch rate over small spatial 

 areas could be examined. In addition, the 

 Fish Commission of Oregon obtained 116 jig 

 boat and 8 bait boat logs, California Depart- 

 ment of Fish and Game made available 45 

 jig boat and 8 bait boat logs, and the Inter- 

 American Tropical Tuna Commission provided 

 2 jig boat and 11 bait boat logs. 



The catches of each type of boat were aver- 

 aged for each day regardless of fishing loca- 

 tion off Oregon. Catches of jig boats were 

 also assigned to 10' latitude X 10' longitude 

 blocks based on their reported loran positions. 

 Generally catches could be assigned to a 

 specific block. If a boat cruised over a large 

 area and catches could not be assigned to 

 specific blocks, the data were not plotted. No 

 adjustment was made for the effect of boat 

 size or number of lines on catches. It should 

 be pointed out that our catch data do not 

 necessarily represent average catches made 

 by the fleet in an area because they are from 

 only part of the fleet. 



Sea-surface temperature was measured on 

 remote sensing overflights using a Barnes 

 PRT-5 infrared radiometer^ at an altitude of 

 150 m or 500 ft (Pearcy and Mueller, 1970). 

 A total of 15 flights were made from 22 July 

 to 15 September on HU-16 aircraft either 

 from the U.S. Air Force 304th Aerospace 

 Rescue and Recovery Squadron, Portland, 

 Oreg., or from the U.S. Coast Guard Station, 

 Port Angeles, Wash. 



On two RV Cayuse cruises, temperature 

 was measured with bathythermographs, and 

 temperature and salinity with a Salinity- 

 Temperature-Depth system. Stations were 

 usually 10 miles apart. On the 27 July- 

 2 August cruise, water transparency was deter- 

 mined with a submarine photometer, and 6-ft 

 Isaacs-Kidd midwater trawl collections were 

 taken at 5 knots to a depth of about 100 m 



along the cruise track at night. Volume of 

 water filtered was estimated from flowmeters 

 mounted in the mouth of the trawl. 



Albacore were caught from the Cayuse by 

 fishing between hydro stations using standard 

 trolling methods with a maximum of eight 

 lines. Time and location of catches during 

 daylight hours were recorded. All fish collected 

 were measured in fork length; stomachs re- 

 moved and preserved immediately with Forma- 

 lin for subsequent examination of their contents. 



CATCHES AND EFFORT 



Statistics on catches and effort of jig and bait 

 boats reporting to us are summarized in 

 Figure 1. The 1970 Oregon jig season got 

 off to an early and intense start. The first 

 albacore of the season were reported on 

 15 July, the day that fishermen and processors 

 reached a price agreement. Thereafter, three 

 , peaks of excellent fishing success occurred 

 for jig boats: on 17, 22, and 28 July. Catches 

 on these days averaged between 300 and 

 400 fish per boat day. The catch rate then 

 declined drastically to about 55 fish per day 

 between 28 and 31 July and never fully re- 

 covered during the remainder of the season, 

 although success improved from 17-20 August. 



•'' Reference to trade names does not imply endorse- 

 ment by the National Marine Fisheries Service, NOAA. 



Figure 1. — Average number of albacore caught per day 

 by jig boats and bait boats that submitted log sheets 

 (above) and the number of reporting boats (below), 

 15 July-20 October 1970. 



The number of jig boats reporting catches 

 increased rapidly after the season began and 

 then declined steadily from 27 July to mid- 

 August (Figure 1). According to Laurs (see 

 footnote 2), as jig fishing deteriorated off 



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