,,3 PATH 



^1 '4 PATH 



Figure 1. --Schematic view of one basket of the 

 longline gear used in albacore fishing by 

 POFI vessels. 



noon and was done in the reverse order of set- 

 ting. The hauling time varied from station to 

 station depending on the number of baskets 

 fished and on the prevailing weather conditions 

 (tables 14 to 16, Appendix) but usually took 

 about 4 hours. 



Three types of trolling--incidental sur- 

 face, deliberate surface, and experimental deep 

 trolling--were used to sample the albacore in 

 this survey. Incidental surface trolling was 

 done at a vessel speed of about 8 knots on the 

 hydrographic and fishing cruises during all day- 

 light runs between stations. Two to five lines 

 were fished, with a boom rigged out annidships 

 when more than three lines were used. The 

 trolling lines, of No. 261 hard-laid cotton line, 

 trailed from 15 to 25 fathonns beyond the stern. 

 The inboard end of the line was secured to a 

 shock-absorber made of a pair of galvanized 

 steel springs 12 inches long ajid 1-1/2 inches 

 in outside dijimeter. The outboard end of the 

 line was joined by a swivel to 1-1/2 fathoms of 

 No. 18 stainless steel wire leader. During the 

 course of each cruise, a variety of lures were 

 used. These included red, white, and amber- 

 colored plastic jigs and feather jigs with plastic 

 or lead heads . Several combinations of white, 

 red, green, and brown feathers were used. 



Deliberate surface trolling with five lines 

 {three from the stern and two from the trolling 

 boom) was done at each longline fishing station 



for 2 hours along the "soaking" line. The 

 makeup of the trolling gear was exactly as 

 described for incidental trolling, but the vessel 

 was slowed to 6 - 6-1/2 knots. 



Deep trolling at a vessel speed of 3 to 

 5 knots was tried at seven longline stations on 

 Manning cruise 23 {December 1954-February 

 1955). The gear had four 10-fathom branch 

 lines {261 cotton line with 1-1/2 fathoms of No. 

 18 wire leader) spaced at 15-fathom intervals 

 on a mainline of 5/32-inch cable. The main- 

 line was weighted with either a 50-pound semi- 

 depressor or a "kite-type" depressor. Both 

 feather lures and fresh frozen sardine were 

 used as bait, the latter being secured to the 

 hook with linen twine, 



WEATHER 



The success of fishing depends to a 

 certain extent on the prevailing weather condi- 

 tions. Longlining becomes hazardous and 

 therefore is generally not attempted in very 

 rough seas or when the winds reach 20 to 30 

 knots. During the three longline cruises storms 

 were encountered which interrupted fishing for 



I to 7 days at a time, and of a total of 91 days 

 spent north of 30 N. latitude, 39 days {43 per- 

 cent) were considered too rough for longlining 

 {table 2). 



ALBACORE 



Distribution and Abundance 



Longline Catches . A total of 52 longline 

 stations were fished during the three cruises. 

 Albacore were taken at 20 stations but the catch 

 on any one station was generally small {tables 



II to 13, Appendix). A notable exception was 



a catch of 42 albacore at station 8 {33 58'N. , 



o 

 159 44'W. ) on Manning cruise 19. 



Two things are apparent from the alba- 

 core catch distribution {fig. 2). First, the 

 northern limit of the albacore distribution was 

 not defined because a combination of adverse 



Table 2. --Sumnmary of weather conditions encountered on POFI 

 cruises north of 30 N. latitude 



