337 
National Marine 
Spencer F. Baird / ' V 
Fisheries Service 
Fishery Bulletin 
First U S Commissioner \ " 
NOAA 
established in 1881 
of Fisheries and founder * 
of Fishery Bulletin fjjjjy 
Distribution of angel sharks (Squatinidae) in United 
States waters of the western North Atlantic Ocean 
Email address for contact author: william.driggers@noaa.gov 
Abstract- —The distributions of 
sharks inhabiting deepwater eco¬ 
systems (>200 m) remain largely 
speculative because of limited collec¬ 
tion efforts for species of relatively 
low commercial value and because 
of difficulties associated with sam¬ 
pling in deepwater habitats. As a 
result, ranges of deepwater shark 
species are often considered con¬ 
tinuous across broad expanses de¬ 
spite records of occurrence, in many 
cases, being spatially fragmented. 
Within United States (US) waters 
of the western North Atlantic Ocean 
(WNA), the range of angel sharks 
(Squatinidae) in continental shelf 
and slope waters has been various¬ 
ly reported as both continuous and 
disjunct. The objective of this study 
was to use fishery-independent 
data to describe the range of angel 
sharks in US waters of the WNA 
and identify potential spatial dis¬ 
continuities that could be consistent 
with the idea of multiple species or 
populations in the region. Results 
indicate that angel sharks in US 
waters of the WNA have a disjunct 
distribution and discontinuities oc¬ 
cur from approximately Georgia 
through southern Florida and within 
a well-defined area off the coast of 
Louisiana. Evidence suggests spatial 
discontinuities could be related to 
thermal, salinity or current veloc¬ 
ity barriers, or to a combination of 
these factors. 
Manuscript submitted 2 July 2018. 
Manuscript accepted 13 September 2018. 
Fish. Bull. 116:337-347 (2018). 
Online publication date: 2 October 2018. 
doi: 10.7755/FB.116.3-4.11 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
William B. Driggers III (contact author) 1 
Matthew D. Campbell 1 
David S. Hanisko 1 
Kristin M. Hannan 1 
Eric R. Hoffmayer 1 
Christian M. Jones 1 
Adam G. Pollack 1 
David S. Portnoy 2 
1 Mississippi Laboratories 
Southeast Fisheries Science Center 
National Marine Fisheries Service, NOAA 
P.O. Drawer 1207 
Pascagoula, Mississippi 39567 
2 Marine Genomics Laboratory 
Department of Life Sciences 
Texas A&M University—Corpus Christi 
6300 Ocean Drive 
Corpus Christi, Texas 78412 
Historically, distributions of shark 
species were based on the amalga¬ 
mation of observational and fish¬ 
ery-dependent data (e.g., Jordan 
and Evermann, 1896; Bigelow and 
Schroeder, 1948). Since the advent 
of fishery-independent surveys, the 
true spatial extent of shark distri¬ 
butions has come into greater focus, 
particularly for species occupying 
neritic habitats. However, distribu¬ 
tions of sharks inhabiting deepwater 
ecosystems (>200 m) remain largely 
speculative owing to limited collec¬ 
tions because of their relatively low 
commercial value and difficulties as¬ 
sociated with sampling in deepwa¬ 
ter habitats. Additionally, the use 
of satellite tagging technology is of 
limited applicability for monitoring 
movements of species found beyond 
the photic zone because of the de¬ 
pendence on light-based geolocation. 
As a result, the ranges of deepwater 
shark species are often considered 
continuous across broad expanses 
despite occurrence records being spa¬ 
tially fragmented. 
Within United States (US) wa¬ 
ters of the western North Atlantic 
Ocean (WNA), sharks from the or¬ 
ders Hexanchiformes, Squaliformes, 
Lamniformes, Squatiniformes, and 
Carcharhiniformes occur in ben¬ 
thic habitats of the outer continen¬ 
tal shelf and slope (Castro, 2011). 
Of these fishes, angel sharks are of 
particular concern because the fam¬ 
ily Squatinidae is reported to be the 
most threatened family of sharks 
globally (Dulvy et ah, 2014). Con¬ 
servation concern for angel sharks 
results from high bycatch rates, 
regional extinctions, relatively k- 
selected life history characteristics, 
data deficiencies (e.g., Colonello et 
ah, 2007; Baremore, 2010; Tagliafico 
et al., 2017), and, importantly, the 
