Hueter et al.: Horizontal and vertical movements of Isurus paucus in the northwestern Atlantic Ocean 
109 
B 
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50-100 
g, 100-200 
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m 200-300 
Q. 300-400 
<13 
Q 
400-500 
>500 
D 
27-30 - 
O 24-27 
O 
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£ 15-18 - 
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2 12-15 - 
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6-9 - 
3-6 - 
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Percent time 
Figure 6 
Depth and temperature histograms for 2 longfin makos (Isurus paucus) tracked with sat- 
ellite-linked tags in the northwestern Atlantic Ocean in 2012 and 2015; (A) mean time-at- 
depth comparison for the 2 sharks LFMl and LFM2, (B) time-at-temperature comparison for 
LFMl and LFM2, (C) day (0800-2000) versus night (2000-0800) comparison of time at depth 
for LFM2, and (D) day versus night comparison of time at temperature for LFM2. 
were from the MAB area (delineated as 35-43°N; 71- 
78°W) and that the greatest proportion were landed in 
July and August (combined 45%) (Cortes®). Of the 11 
geographic areas covered by the POP, only the GOM 
had a larger proportion of longfin mako captures (34%) 
than the MAB (Cortes®). 
Diel vertical movement 
The depth and temperature data from the tags of LFMl 
and LFM2 indicate a daily pattern of vertical movement 
® Cortes, E. 2015. Personal commun. Southeast Fish. Sci. 
Cent., Natl. Mar. Fish. Serv., 3500 Delwood Beach Rd., Pan- 
ama City, FL 32408-7403. 
® Cortes, E. 2015. Personal commun. Southeast Fish. Sci. 
Cent., Natl. Mar. Fish. Serv., 3500 Delwood Beach Rd., Pan- 
ama City, FL 32408-7403. 
between near-surface waters and the mesopelagic zone, 
with overall depth and temperature ranges of 0-1767 
m and 4.0-28.8° C. A pattern of DVM was evident with 
greater time at depth during the day and more time in 
the mixed layer at night. These observations are con- 
sistent with longline catches of longfin makos in that 
most captures occur during overnight sets with baits 
set at depths of 0-220 m below the surface (Dodrill 
and Gilmore, 1979; Queiroz et al., 2006; Hemida and 
Capape, 2008; Bustamante et al., 2009). Satellite track- 
ing results for its congener, the shortfin mako, indicate 
a similar DVM pattern, but shortfin makos do not ap- 
pear to have as great a tolerance for depth and cold 
temperatures. In the western North Atlantic Ocean, for 
example, a tagged shortfin mako had depth and temper- 
ature ranges of 0-556 m and 10.4-28.6° C (Loefer et al., 
2005), and results from tracking a shortfin mako in the 
