402 
Fishery Bulletin 118(4) 
Table 2 
Summary of fishery-dependent data by life stage and sex as well as the range of associated sea-surface 
temperatures (SST) and depths from capture records 
for common thresher sharks (Alopias vulpinus) 
in the western North Atlantic Ocean between 1964 and 2019. Ranges and means, with standard devi- 
ations in parentheses, are presented for SST and depth. YOY=young of the year; unknown=unknown 
life stage or sex. 
Number of records 
Life stage Male Female Unknown 
YOY 425 432 279 
Juvenile 338 376 369 
Adult 182 83 158 
Unknown 90 148 598 
Overall 1035 1039 1404 
Bottom longline Haul seine 
Gear type 
Percentage of records 
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AAS 
Year 
Figure 
SST (°C) Depth (m) 
Range Mean Range Mean 
6-26 16 (3) 1—2077 21 (86) 
6-31 17 (4) 1—4535 262 (556) 
5-30 18 (4) 1-5401 414 (902) 
4-30 18 (4) 1-5427 1197 (1581) 
4-31 17 (4) 1-5427 434 (1039) 
Otter trawl | Purse seine 
Gill net Mid-water trawl | Pelagic longline | Rod and reel 
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TANNNAANNANNANANANNNNANAOAOAN 
1 
Percentage of the total number of capture records from fishery-dependent data, by gear type, and 
the total number of records, by year, for common thresher sharks (Alopias vulpinus) in the western 
North Atlantic Ocean from 1964 through 2019. The shade or pattern of each bar indicates gear 
type, and the solid line indicates number of records. 
records obtained per year ranged from 1 to 538 (mean: 76 
[standard deviation (SD) 109]) with 48.7% of all records 
occurring between 2015 and 2019 (Fig. 1). Lengths were 
available for 3072 (88.3%) individuals, including 1720 
(49.4%) sharks that were measured and 1352 (38.9%) 
sharks whose lengths were estimated either at the time of 
capture or by a length conversion. Measured FLs ranged 
from 59 to 320 cm (mean: 125 cm [SD 48]), and estimated 
FLs ranged from 60 to 330 cm (mean: 160 cm [SD 56]) 
(Fig. 2). Five length records were eliminated because of 
biologically implausible length estimates or measure- 
ments. Life stage was assigned to 2642 (76.0%) sharks of 
which 1136 (32.7%) were YOY, 1083 (31.1%) were juvenile, 
and 423 (16.0%) were adult (Table 2, Fig. 2). Sex was noted 
for only 21 of the sharks captured in Canada; therefore, 
any comparisons among sexes and juvenile and adult life 
