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Fishery Bulletin 106(4) 
Table 1 
Overview of recaptured (Rec.) archival tags from Greenland halibut (Reinhardtius hippoglossoides) . Fish total length (TL, cm) 
measured during tagging. F=female; M=male. 
Rec. no. 
Interval between 
recording (min) 
Release date 
No. of days 
recording 
Fish TL 
Fish sex 
1 
60 
30.11.02 
687 
67 

2 
60 
08.12.02 
334 
64 
F 
3 
60 
08.12.02 
24 
68 
— 
4 
60 
08.12.02 
188 
61 
— 
5 
60 
08.12.02 
12 
54 
M 
6 
60 
12.12.02 
18 
67 
F 
7 
60 
13.12.02 
16 
67 
F 
8 
60 
13.12.02 
70 
74 
F 
9 
10 
12.08.03 
151 
57 
— 
10 
10 
14.08.03 
149 
57 
— 
11 
15 
14.08.05 
306 
76 
F 
12 
15 
14.08.05 
120 
63 
F 
13 
15 
15.08.05 
54 
66 
F 
14 
15 
15.08.05 
67 
77 
F 
15 
15 
15.08.05 
296 
74 
F 
16 
15 
15.08.05 
10 
57 
— 
17 
15 
15.08.05 
8 
73 
F 
18 
15 
15.08.05 
51 
55 
F 
19 
15 
16.08.05 
54 
63 
F 
20 
15 
16.08.05 
61 
75 
F 
21 
15 
16.08.05 
177 
77 
— 
22 
15 
16.05.06 
261 
67 
— 
23 
15 
16.05.06 
261 
47 
F 
24 
15 
16.05.06 
99 
68 
F 
25 
15 
17.05.06 
196 
65 
— 
Total effort within ij was the sum of E ljk for k=(\ to AL), 
where N i; is the number of vertical longlines in ij. 
Demersal longlines 
Length-frequency distribution data of Greenland halibut 
on the bottom (separated by sex) were collected by using 
demersal longlines. In August 2005 the demersal long- 
lines were 3.5 km long and were deployed in an east-west 
direction perpendicular to the continental slope. Fishing 
depth ranged from 450 to 950 m (mean of 655 [±155] 
m). Soak time ranged from 3 to 22 hours (mean of 10.7 
[±5.2] hours). The hooked section on demersal longlines 
was identical to that of vertical longlines. 
Archival tags 
On four occasions (November 2002, August 2003, August 
2005, and May 2006) a total of 503 Greenland halibut 
were tagged with archival tags (DST milli or DST Pitch 
and Roll, Star-Oddi, Reykjavik, Iceland). All individuals 
were tagged from demersal longlines within the central 
study area. The longlines were carefully hauled and only 
individual fish in apparently good shape were tagged 
and then immediately released. Recaptures were made 
with bottom trawls, mainly along the continental slope 
(Fig. 1). The tags were programmed to record time and 
ambient depth (pressure) every 10, 15, or 60 minutes, 
and the depth trajectories were recovered after recap- 
ture. Up to October 2007, a total of 38 (7.6%) of the 
released tags were recaptured. Of the recaptured tags, 
13 had been destroyed and there was no possibility of 
data extraction. Of the 25 tags containing data, three 
tags had stopped recording after being exposed to depths 
greater than 1000 m, and six tags had stopped record- 
ing because the memory was full. For the remaining 
16 tags, data were recovered for the whole period from 
release to recapture. Table 1 shows recording sequence, 
number of data sampled, as well as sex and length of the 
tagged individual for all 25 tags used in the analysis. 
These tagging experiments will form the basis for more 
detailed future publications; here we restrict ourselves 
to consider the vertical activity and compare it with the 
results from the vertical longline experiments. 
The tags, by design, conveyed no direct information 
on bottom depth or the distance from the bottom. How- 
ever, it was assumed that readings of constant ambient 
depth can only occur when the fish are on the bottom, 
