KEENE and PEARCY: COMPARISON OF SUCCESS OF ALBACORE TROLL FISHERMEN 



lowliners occurred in 1968 (Figure 2). Highliners 

 fished almost exclusively to the northwest and 

 southwest of the fleet center. When abundance 

 was low and effort high (26 July-3 August), high- 

 liners moved far from the fleet center, as seen in 

 the southwest quadrant. During 5 and 6 August, 

 when high catches coincided with high levels of 

 effort, highliners were found close to the fleet 

 center, but not as close as during periods of low 

 effort. Lowliners fished mainly to the south and 

 away from the fleet center during all levels of 

 abundance. When abundance was high (5-8 

 August), lowliners in the southeast quadrant 

 moved closer to the fleet center. Later as catches 

 declined, the lowliners moved away from the 

 center (southeast quadrant, 9-15 August). 



There was no obvious separation of highliners 

 and lowliners in 1969 (Figure 3) comparable to 

 1968. Highliners fished in all quadrants, as did 

 lowliners. Some highliners fished away from the 

 fleet center during periods of low abundance (31 

 July-2 August; 5-12 August), particularly in the 

 northwest and southwest quadrants when effort 

 was high (10-12 August). Lowliners again fished 

 more in the southern quadrants than did high- 

 liners but not exclusively so and not as far from 

 the fleet center as in 1968. In fact, most lowliners 

 were located near the fleet center until all catches 

 began decreasing after 5 August. Then, some 

 lowliners moved away from the fleet (southwest, 

 northeast; 10-11 August) but the majority 

 remained near the fleet center. 



The short 1970 season provided little informa- 

 tion on the responses of highliners and lowliners 

 (Figure 4). As the season began (19-21 July) 

 highliners were fishing at some distance from the 

 fleet center. During the period of very high catches 

 (22-29 July) both highliners and lowliners fished 

 within 40 miles of the fleet center. No boat 

 reported a location farther than 80 miles from the 

 center during this time. There was no indication 

 that either group dispersed in response to the high 

 levels of effort and aggregation of boats which 

 occurred. On 22 July, when separation distance 

 was lowest and on 26 July when effort was highest, 

 most highliners were fishing within 20 miles of the 

 fleet center. 



Most highliners did not fish Oregon waters after 

 30 July, the day catches dropped precipitously. The 

 lowliners that stayed were northwest of the fleet 

 center. Catches never returned to their original 

 high levels, and on 4 August the season was 

 essentially over for the troll boats. 



Some albacore fishermen believe that large 

 numbers of small fish are located in the offshore 

 fishing area and that highliners are able to exploit 

 these fish to a greater degree because of their 

 greater endurance and seaworthiness. To test this 

 hypothesis, the average weight of each fish per trip 

 reported by highliners during July and August 

 was compared with the average fish weight per 

 trip for lowliners. The results, given in Table 4, 

 show that highliners caught significantly smaller 

 fish than lowliners. This supports the fishermen's 

 belief that smaller fish are found along the 

 offshore margins of the fishery where highliners 

 often fish, while larger fish are found along the 

 inshore margins of the fishery where lowliners 

 expend more effort. 



The difference between average daily net travel 

 of highliners and lowliners, based on 2100 h PDT 

 positions, changed significantly within the 3 yr. 

 Highliners in 1968 moved 10 miles less per day 

 than did lowliners (Table 3). In 1969 and 1970 there 

 was no statistical difference between the average 

 distance traveled by the two groups. Travel dis- 

 tances in Table 3 can be compared with the daily 

 travel of the fleet center (Figure 5). The fleet 

 center moved an average of 14 miles per day in 

 1968, 29 miles per day in 1969, and 29 miles per day 

 in 1970. Highliners moved in a much closer rela- 

 tionship with the fleet in 1968 than did lowliners. 

 Lowliners in 1968 traveled twice as far as the 

 general fleet, yet lagged behind the fleet's north- 

 erly movement. This was much less apparent in 

 1969 and 1970. 



A comparison of average relative fishing powers 

 showed that highliners of 1968 and 1969 were 

 about three times more successful than lowliners in 

 catching fish (Table 3). Lowliner fishing power 

 decreased in 1969, even though lowliner and high- 

 liner boat lengths and daily distances traveled 

 were similar. In 1970 lowliner and highliner char- 

 acteristics were quite simlar to those of 1969, 

 except for calculated fishing power. In 1970 fishing 

 power of lowliners increased while that of high- 

 liners decreased. This was probably due to the 



Table 4.-Average weight (kilograms) of individual albacore per 

 trip taken by highliners and lowliners during July and August 

 1968, 1969, and 1970. 



981 



