Bond and James: Postrelease movements of Dermochelys coriacea in the Atlantic Ocean 257 
(Table 1), and they presented with rope wrapped multiple 
times around the front flippers, or the flippers and neck, as 
is commonly documented among leatherbacks entangled 
in fixed-gear fisheries in Atlantic Canada (Hamelin et al., 
2017). Following complete removal of all entangling fish- 
ing gear, each turtle was visually examined for injuries, 
and its condition was assessed. Turtles were measured 
and photographed. Sex was determined for individuals 
with curved carapace length (CCL) 2145 cm on the basis of 
phallus display or tail morphology, and turtles with CCL 
<145 cm were classified as juveniles (Eckert, 2002). Tis- 
sue samples were obtained by using a 5-mm biopsy punch 
(Acuderm Inc.!, Fort Lauderdale, FL), and identification 
tags (Monel flipper tags and passive integrated transpon- 
ders) were applied. 
Turtles were equipped with satellite transmitters 
(models SSC3 [n=1], SPOTS [n=1], or MK10-AF [n=2], 
Wildlife Computers Inc., Redmond, WA), by using har- 
nesses (n=2) or direct attachment (n=2) (Hamelin and 
James, 2018). After tagging, turtles were immediately 
released. Location data were transmitted through the 
Argos satellite network, and locations classified as LC3, 
LC2, LC1, and LCO and estimated to be within 150 m, 
150-350 m, 350-1000 m, and >1000 m of true locations 
were retained for analysis (Fig. 1). Data processing and 
analyses were conducted by using statistical software R, 
vers. 3.6.1 (R Core Team, 2019), and tracking data were 
plotted by using ArcMap 10.7 (Esri, Redlands, CA). Pro- 
tocols for disentanglement, sampling, and satellite-tag 
attachment were approved by the Dalhousie University 
Committee on Laboratory Animals or the Fisheries and 
Oceans Canada Maritimes Animal Care Committee to 
meet standards established by the Canadian Council 
on Animal Care. Data and interaction details for turtles 
E-S (Table 1) were obtained from previously published 
tracks of satellite-tagged leatherbacks following their 
release from fishing gear. 
Results and discussion 
Turtles A-D were active and responsive at the time of 
release; they displayed only minor abrasions and vigorous 
movements. Satellite tracking durations spanned 210-— 
537 d, with an average of 9754 km (standard deviation [SD] 
3790.6) travelled and mean travel rates from 1.130 km/h 
(SD 0.791) to 1.430 km/h (SD 0.960) (Table 1). Turtle B 
immediately swam south and departed continental shelf 
waters after release. However, the other turtles remained 
in northern continental shelf waters off Canada and the 
United States throughout the summer-fall foraging sea- 
son, before eventually migrating to low latitudes for the 
winter (Fig. 1). Such behavior is consistent with move- 
ment patterns exhibited by free-swimming leatherbacks 
tracked following directed-capture sampling in Canada 
' Mention of trade names or commercial companies is for identi- 
fication purposes only and does not imply endorsement by the 
National Marine Fisheries Service, NOAA. 
or from nesting beaches (James et al., 2005). Tags on 
3 turtles ceased transmitting data during the winter 
following tag deployment; however, turtle A was tracked 
through a second foraging season in waters off Atlantic 
Canada (for a total tracking duration of 537 d). 
Travel rates for turtles A-D were similar to those 
of leatherbacks tracked following directed capture off 
Nova Scotia (Jonsen et al., 2006) and after departing 
nesting beaches in Trinidad (Eckert, 2006) and French 
Guiana (Fossette et al., 2008). Three of the 4 turtles 
were not observed again after tagging. However, Turtle D 
was subsequently recorded nesting at Matura Beach, 
Trinidad, in 2014, 2017, and 2019 (when replacement 
satellite tags were deployed) and was tracked back to 
waters off Atlantic Canada in 2017, 2019, and 2020. Tur- 
tle D’s foraging, migratory, and nesting history spanning 
8 years from the first tag deployment is compelling evi- 
dence for a lack of long-term behavioral or fitness effects 
associated with the original capture and tagging of this 
individual. 
The mean tracking duration for leatherbacks after 
they were disentangled and released (all deploy- 
ments, Table 1) was 232.58 d (SD 165.61; n=19). Most 
(74%) leatherbacks were tracked for over 100 d, with 
many completing large-scale migrations throughout the 
deployment period (Doyle et al., 2008; Almeida et al., 
2011; Dodge et al., 2014) (Fig. 1). The mean tracking dura- 
tion of leatherbacks after disentanglement and release 
in our analysis was not significantly different from the 
tracking durations of live-captured leatherbacks docu- 
mented by Hamelin and James (2018) (P=0.538). Impor- 
tantly, the sample considered here includes leatherbacks 
interacting with a variety of fisheries throughout the 
Atlantic Ocean and encompasses turtles that presented 
as vigorous and lacking apparent external injuries at 
the time of tagging (turtles A-D) (Doyle et al., 2008) and 
others that had clearly sustained injuries (Innis et al., 
2010; Dodge et al., 2014). The tracking results here (tur- 
tles A-S, Table 1), coupled with the high rate of scarring 
likely caused by fishery interactions observed among 
nesting and foraging leatherbacks (Archibald and James, 
2018), indicate that many leatherbacks can recover from 
entanglement events. Dodge et al. (2014) established 
that some of the turtles they tracked were previously 
entangled, and at least one tagged turtle had sustained 
injuries from constricting and cutting lines (Innis et al., 
2010). Others, however, only had minor abrasions. It is 
unclear if the short tracking durations (<50 d, Table 1) 
among the leatherbacks considered from other studies 
correspond to turtles that had severe entanglement inju- 
ries and were judged by Innis et al. (2010) to be in rela- 
tively poor health. 
The satellite tracking data reviewed and presented here 
are from a variety of satellite transmitter models with 
varying sensor options, sampling and transmission 
regimes, and battery capacities. Biofouling, broken anten- 
nas, and premature detachment can contribute to cessa- 
tion of satellite tag transmissions, affecting tracking 
durations (Hays et al., 2007). These confounding factors, 
