Dagorn et al.: Association of Thunnus albacores with tracking vessels 
43 
15CT54W 
1 8° 1 0 S 
06 00 
Day 20 April 
1000 14:00 
B 
1800 18:00 
06:00 
0 
Day 21 April 
10:00 14:00 
50 
100 
150 
t 2 
200 
Depth (m) 
Night 20/21 April 
22.00 02:00 
06 00 
0 
50 
100 
150 
200 
Depth (m) 
D Night 21/22 April 
18:00 18:00 22:00 02:00 06:00 
1 >vf 
J 
50 
100 -f- 
150 
200 
Depth (m) 
06:00 
0 
Day 22 April 
1000 1400 
18:00 
50 
100 4 
150 -4 f 
200 -L 4 5 
Depth (m) 
G 
06 00 
10:00 
14:00 
18 00 
18.00 
Depth (m) 
H 
18:00 
Night 22/23 April 
22:00 02:00 06 00 
22 00 
02 00 
06 00 
Figure 3 
Horizontal and vertical movements of yellowfin tuna 3, 108 cm FL. Tracking lasted 91 h (April 
1998). This fish was always associated with the tracking vessel. Arrows indicate the direction of 
horizontal movement in the upper graph. Changes in the movements of the tracking vessel are rep- 
resented by vertical arrows on the graphs representing the vertical movements of the fish. 1 = the 
vessel left FAD1 to move to FAD2 during the night; 2 = the vessel arrived at FAJD2; 3 = the vessel 
left FAD2 to go to FAD3; 4 = the vessel arrived at FAD3. 5 = the vessel left the FAD to go close to 
the Maiao island; 6 = the vessel came back to FAD3 and start drifting; 7 = the vessel moved away 
from FAD to conduct trawl and acoustic survey operations. 
