490 
Fishery Bulletin 11 5(4) 
Figure 4 
Before-and-after images of hook wounds, with scale (in millimeters), that resulted from use of 
the poker-and-hook tool to capture nurse sharks (Ginglymostoma cirratum) in Florida during 
2014. (A) Wound shows minimal blood (a few drops), then (B) healthy mucus secretion after 
9 days; (C) a wound with no blood, then (D) epidermal regeneration and repair scales present 
after 22 days; and (E) a wound with residual blood, then (F) fully formed mineralized scales 
present in the scar after 42 days. 
Szedlmayer, 2004; Braccini et al., 2012; Danylchuk et 
al., 2014), low levels are still arguably of concern for 
important apex predators such as sharks. Local popu¬ 
lations of sharks are likely highly susceptible to even 
low levels of postcapture mortality because of life his¬ 
tory characteristics such as low reproductive output 
(e.g., litter size) and late age-at-maturity (Stevens et 
al., 2000; Dulvy and Forrest, 2012). 
The intake canal at the Florida Power and Light 
St. Lucie Nuclear Power Plant provided an ideal envi¬ 
ronment to monitor nurse sharks over time after their 
capture by the poker-and-hook method. All 20 nurse 
sharks captured by this method showed no immediate 
ill effects and the 9 individuals monitored between 9 
and 42 days survived with no observed abnormal be¬ 
havior (although behavior was not evaluated in a sys¬ 
tematic way). All wounds from the poker-and-hook cap¬ 
ture method were either healing well or fully healed 
during this period and no signs of inflammation of tis¬ 
sue deterioration occurred. 
The 4 nurse sharks whose weights were recorded be¬ 
fore and after 22-24 days all increased in weight. This 
further corroborates evidence of a quick recovery and 
minimal postcapture stress. When the 3 nurse sharks 
were put into the tank, they fed immediately, as well 
as voraciously, and continued to do so at each feeding 
every 3-4 days. The sharks were fed to satiation and 
any uneaten food (freshly chopped fish) or small live 
fish that we stunned and that settled on the tank bot¬ 
tom would be eaten overnight, thereby suggesting that 
no injury occurred to the lateral line system (which is 
used in prey detection and contributes to the localiza¬ 
tion of food by the olfactory organs; see Kleerekoper 
and Gruber, 1975; Gardiner and Atema, 2007; Gardin¬ 
er, 2012) or that any resulting injury to the lateral line 
could be deemed negligible. 
An important stage in wound healing in sharks is 
the continual replacement of their dermal denticles 
(scales) (Reif, 1978). The extraordinarily tough skin of 
nurse sharks further makes them well suited for the 
poker-and-hook capture method. Both male and female 
nurse sharks are characterized by their thick, dense 
integument known to withstand multiple bites during 
mating (Klimley, 1980; Pratt and Carrier, 2001) and to 
resist damage while living in typical habitats of rock 
and coral (i.e., sustaining collisions with reef substrate 
during pursuit of prey; Campagno, 2002; senior author, 
personal observ.). The sides of the tail base are also 
without lateral keels or precaudal pits that could af¬ 
fect hooking efficacy or injury (or both). More impor¬ 
tantly, the main circulatory vessels taper at the tail 
base (Rosenzweig, 1988), which is dense in muscle and 
is reported as damage tolerant (Naresh et al., 1997; 
Towner et al., 2012). The caudal area further appears 
to be well suited for this capture method because evi¬ 
dence suggests that drawing blood from this area is 
also less physiologically taxing (Cooper and Morris, 
1998; Mandelman and Skomal, 2009) and the upper- 
and-lower targeted part of the tail base (away from the 
lateral line) has very little vascularization (Shadwick 
and Goldbogen, 2012). 
Of the 23 hook wounds resulting by this capture 
method, 9 hook wounds did not bleed and 14 hook 
wounds showed only minimal bleeding (a couple drops 
