534 
Fishery Bulletin 11 5(4) 
Charlotte Harbor and surrounding waters in the Gulf 
of Mexico (26°47'18"N, 82°7'23"W), and off Cape Ca¬ 
naveral (28°19'8"N, 80°20'6"W) in the Atlantic Ocean. 
At both study sites, specific fishing locations and 
practices were directed by recreational charter cap¬ 
tains to ensure methods were consistent with those 
commonly used in the recreational fishery. Sharks 
were caught between September 2011 and April 2013 
by using rod and reel with 10/0 circle-hooks (circle 
offset-point octopus hook; Gamakatsu USA, Inc., Ta¬ 
coma, WA) or 10/0 J-hooks (straight eye 4x strong 
offshore octopus hook; Gamakatsu USA, Inc.) baited 
with locally caught species, such as Spanish mack¬ 
erel (Scomberomorus maculatus) and Atlantic bo- 
nito (Sarda sarda) and identical angling practices 
were used regardless of hook type. Once sharks were 
hooked, they were angled until they could be handled 
alongside the boat, at which point they were roped 
by the tail and secured to the side of the vessel with 
the shark facing toward the bow. The sharks re¬ 
mained in the water to ensure that their gills were 
oxygenated. The time from when the shark initially 
was hooked until it was secured alongside the ves¬ 
sel was recorded as fight time. Once secured, precau- 
dal length, girth, and hooking location (jaw, mouth, 
gill, esophagus, gut, body) were recorded; and sharks 
were visually assessed for abrasions or bleeding. Af¬ 
ter initial assessments, an ADL was attached to the 
shark’s dorsal fin and a sample of blood was drawn 
by a caudal venipuncture. Once sampling and tag¬ 
ging were completed, the hooks were removed or the 
leaders were cut at the captain’s discretion. Blacktip 
sharks are obligate ram ventilators, but are able to 
endure short periods of restraint when their gills are 
flushed by ambient water movement alongside the 
vessel. If sharks were unresponsive after processing, 
they were revived by moving them forward and back¬ 
ward in the water to ventilate their gills—a standard 
practice among recreational fishermen and one rec¬ 
ommended in fishery guidelines issued by NOAA and 
others (e.g., NMFS 3 ). Sharks were assigned a behav¬ 
ioral release condition score (BRCS) between 1 and 5 
upon release (l=good: no revival time, swiftly swim¬ 
ming away; 2=fair: no revival time, slowly swimming 
away; 3=poor: short revival time <30 s; 4=very poor: 
long revival time >30 s; and 5=dead: unable to re¬ 
vive), which has been shown to correspond with sur¬ 
vival for this species on the basis of long-term recap¬ 
ture rates (see Hueter et ah, 2006). The time from 
when the shark was initially secured to the side of 
the vessel until it swam away was recorded as han¬ 
dling time. Immediately after release, environmen¬ 
tal parameters (temperature, dissolved oxygen) were 
measured by using a YSI Model 85 probe (YSI, Inc., 
Yellow Springs, OH). 
3 NMFS (National Marine Fisheries Service). 2013. Recre¬ 
ational shark fishing—healthy catch & release. [Available 
from website.] 
Blood sampling and analysis 
Once animals were restrained and measured, 1 cc of 
blood was drawn by caudal venipuncture with an 18- 
20 gauge 3.8-cm nonheparinized syringes (Mandelman 
and Farrington, 2007; Skomal, 2007). To avoid coagula¬ 
tion and not compromise blood gas accuracy after phle¬ 
botomy, sampled whole blood was immediately (within 
30 s) analyzed for pH, pC0 2 , and lactate concentra¬ 
tion (La - ) in a portable blood gas analyzer (VetScan 
i-STAT; Abaxis North America, Union City, CA) ther- 
mostatted to 37°C. These values were then corrected 
to environmental temperature according to Mandelman 
and Skomal (2009). 
Accelerometer deployment and recovery 
To monitor postrelease mortality and behavior, sharks 
were tagged with ADLs (G6a; Cefas Technology, Ltd., 
Lowestoft, UK) set to record tri-axial acceleration at 25 
Hz, depth at 1 Hz, and temperature at 0.033 Hz. Accel¬ 
eration data loggers and a VHF transmitter were em¬ 
bedded in a custom-made float (7x11 cm, 125 g in air, 
70 g positively buoyant in seawater; Fig. 1) and affixed 
to the left side of the dorsal fin with plastic cable ties 
and a galvanic timed release (International Fishing 
Devices, Inc., Northland, New Zealand; Whitmore et 
ah, 2016). After a predesignated period of time (12-72 
h), the galvanic release dissolved in seawater, releasing 
the ADL package and allowing it to float to the surface 
for recovery. Floating tag packages were detected with 
a hand-held VHF receiver (R4520C; Advanced Telem¬ 
etry Systems, Isanti, MN), then retrieved by vessel; for 
more information on tagging and recovery methods see 
Lear and Whitney (2016) and Whitmore et al. (2016). 
ADL data processing and analysis 
Data from the ADLs were analyzed with Igor Pro 
software, vers. 6.22 (WaveMetrics, Inc., Lake Oswego, 
OR) and Ethographer (Sakamoto et ah, 2009). Data 
for each individual’s ADL were visually inspected for 
postrelease mortality, indicated by a constant depth 
and cessation of tailbeats that were evidence of a 
lack of movement and, for an obligate ram-ventilating 
shark, ultimately death (Whitney et ah, 2016). Erratic 
tailbeats could continue for several minutes but, for 
consistency, time of death was considered to be the fi¬ 
nal time that the shark came to rest on the seafloor. 
Using the data from the ADLs, we generated 58 met¬ 
rics of swim performance according to Whitney et al. 
(2016). The metrics included tailbeat acceleration am¬ 
plitude (TBAA), tailbeat cycle (TBC), overall dynamic 
body acceleration (ODBA; Wilson et ah, 2006), and 
ODBA bursts, while from the depth information we 
derived number of dives, duration of dives, average 
depth, and average vertical velocity (W) for each hour 
(Whitney et ah, 2016). Because sharks are negatively 
buoyant, their swimming dynamics differ depending 
on their orientation and vertical direction of travel. 
